bluuebunny/crossref_metadata_2025 huggingface dataset:
Habitual walking speed and fatigue explain self‐reported functional capacity after stroke
Authors: Polese Janaine Cunha , Albuquerque Thaís Bueno Dias , Faria‐Fortini Iza , Teixeira‐Salmela Luci Fuscaldi
Published: December 2022

Introduction

Individuals after stroke present several motor impairments, which reduced the functional capacity. The understanding of modifiable factors which are related to functional capacity in individuals with chronic stroke could better direct clinical practice. However, the mechanisms that could influence functional capacity in individuals with chronic stroke are not fully understood.

Objective

This study aimed to determine which modifiable variables would best predict self‐reported functional capacity after stroke.

Design

Cross‐sectional.

Setting

Research laboratory setting.

Participants

Ninety two individuals with chronic stroke, who had a mean age of 60 (SD 13) years and a time since the onset of the stroke of 52 (67) months.

Main Outcome Measures

Regression analysis of cross‐sectional data was used to investigate whether body mass index, habitual walking speed, physical activity levels, fatigue, motor recovery, walking distance, and residual strength deficits of the lower limb muscles would predict self‐reported functional capacity.

Results

Habitual walking speed alone explained 48% of the variance in functional capacity. When fatigue was included in the model, the explained variance increased to 55%.

Conclusions

Habitual walking speed and fatigue were significant predictors of self‐reported functional capacity in individuals with chronic stroke. These individuals may increase their functional capacity with interventions aimed at increasing walking speed and reducing fatigue.
Robotic resection of paediatric solid tumours at a single institution
Authors: Pu Jiarui , Li Hang , Liu Yuan , Hong Mei , Li Shiwang , Tang Shaotao
Published: December 2022

Background

To explore the clinical application of robotic‐assisted surgery in paediatric solid tumours and to explore its feasibility.

Methods

From 2015 to 2022, 53 children with solid tumours underwent robotic‐assisted surgery in our centre were retrospectively analysed.

Results

The mean weight of the patients was 27.7 kg, and the mean age was 6.7 years. The average tumour volume was 5.5*4.6*3.7 cm. Two procedures (3.8%) were converted. The mean total operative time was 198.5 min. The mean estimated blood loss was 27.1 ml, and no intraoperative complications occurred. Two (3.8%) patients had postoperative complications. At a median follow‐up of 21.2 months, one (1.9%) patient with malignant tumours stopped treatment, and two (3.8%) patients developed tumour recurrence.

Conclusions

Robotic‐assisted tumour resection is feasible in highly selected cases of young age, light weight, huge tumour or malignant tumour.
Numerical simulation of transport phenomena and its effect on the weld profile and solute distribution during laser welding of dissimilar aluminium alloys with and without beam oscillation
Authors: Mohan Anand , Franciosa Pasquale , Ceglarek Dariusz , Auinger Michael
Published: December 2022

Remote Laser Welding (RLW) of Aluminium alloys has significant importance in lightweight manufacturing to decrease the weight of the body in white. It is critical to understand the physical process of transport phenomena during welding which is highly related to the mechanical performance of the joints. To investigate the underlying physics during welding and to understand the influence of beam oscillation on heat transfer, fluid flow and material mixing a transient three-dimensional Finite Element (FE) based Multiphysics model has been developed and validated from the experiments. The effect of welding speed, oscillation amplitude and oscillation frequency on the fusion zone dimensions, flow profile, vorticity profile, cooling rate and thermal gradient during the butt welding of Al-5754 to Al-6005, with sinusoidal beam oscillation, is analysed. It was found that one additional vortex is formed during beam oscillation welding due to the churning action of the oscillating beam. With the increase in oscillation amplitude, welds become wider and the depth of penetration decreases. An increase in oscillation frequency leads to an increase in the flow rate of the molten metal suggesting that the beam oscillation introduces a churning action that leads to an increase in mixing. It was highlighted that the material mixing depends on both diffusion and convection.
Antioxidant content and volatile composition of seedless table grape (Vitis vinifera L.) varieties
Authors: Blanch Gracia Patricia , Suarez-Coca Diana , de Pascual-Teresa Sonia , del Castillo María Luisa Ruiz
Published: December 2022

Grapes are important sources of phenolics, which are recognized to possess high biological value. In this work, we evaluated the total phenol content (TPC), total anthocyanin content (TAC), antioxidant activity (AA) and volatile composition of unstudied seedless table grape varieties (i.e., Autumn Crisp and Pristine as white cultivars, Scarlotta and Crimson as red cultivars and Adora and Melody as black cultivars). As a result, Adora and Melody exhibited higher TPCs, TACs and AA, measured by the 2,2-diphenyl-2-picrylhydrazil (DPPH) and photochemiluminescence (PCL) assays, than the rest of the varieties. A comparison between the two black cultivars proved that Adora possessed higher TPC (62.70 mg GAE 100 g−1), DPPH radical scavenging activity (IC50of 3.69 mg ml−1) and PCL antiradical activity (72.14 µg Trolox ml−1) than Melody (47.30 mg GAE 100 g−1, IC50of 5.0 mg ml−1and 42.36 µg Trolox ml−1, respectively). The volatile composition, determined by solid phase microextraction (SPME)–gas chromatography/mass spectrometry (GC/MS), indicated a similar qualitative aroma profile for all varieties. However, quantitative differences were measured among them, which were reflected in distinct sensory perception by sensorial testing. From these results, Adora was selected for its antioxidant properties and flavor characteristics.
On the Two-Point Function of the Potts Model in the Saturation Regime
Authors: Aoun Yacine , Ott Sébastien , Velenik Yvan
Published: December 2022

We consider the Random-Cluster model on$${\mathbb {Z}}^d$$Zdwith interactions of infinite range of the form$$J_x = \psi (x){\mathsf {\scriptstyle e}}^{-\rho (x)}$$Jx=ψ(x)e-ρ(x)with$$\rho $$ρa norm on$${\mathbb {Z}}^d$$Zdand$$\psi $$ψa subexponential correction. We first provide an optimal criterion ensuring the existence of a nontrivialsaturationregime (that is, the existence of$$\beta _{\textrm{sat}}(s)>0$$βsat(s)>0such that the inverse correlation length in the directionsis constant on$$[0,\beta _{\textrm{sat}}(s)$$[0,βsat(s))), thus removing a regularity assumption used in our previous work (Aoun et al. in Commun Math Phys 386:433–467, 2021). Then, under suitable assumptions, we derive sharp asymptotics (which are not of Ornstein–Zernike form) for the two-point function in the whole saturation regime$$(0,\beta _{\textrm{sat}}(s))$$(0,βsat(s)). We also obtain a number of additional results for this class of models, including sharpness of the phase transition, mixing above the critical temperature and the strict monotonicity of the inverse correlation length in$$\beta $$βin the regime$$(\beta _{\textrm{sat}}(s), \beta _{\mathrm {\scriptscriptstyle c}})$$(βsat(s),βc).
Development of eco-friendly colored/multifunctionalized cellulose/polyester blended fabrics using plasma preactivation and subsequent coloration/multifunctionalization in single stage
Authors: Ibrahim Nabil A. , Eid Basma M. , El-Zairy Enas M. , Abd Almaksoud Sara E. , Khalil Heba M.
Published: December 2022

A new green approach was developed in the present study to pre-activate and modify the cellulose/polyester blended fabrics surfaces using atmospheric plasma, as a green alternative to non-eco-friendly conventional chemical modification processes, followed by post-dyeing/functional finishing to obtain high value-added, multifunctional, protective and colored blended fabrics. The obtained results demonstrated that the imparted antibacterial and anti-UV functional properties and the increase in color strength are greatly improved owing to plasma pre-modification step. Type of plasma gas, O2− or N2−, blended substrate, cotton/polyester (C/PET) or viscose/polyester (V/PET), kind of coloring agent: pigment, basic dye or curcumin natural dye, as well as the chemical nature of functional additive: thyme oil, clove oil, lavender, tulsi, ginger, vanillin, ascorbic acid or salicylic acid, ZnO − or Al2O3− NPs have a significant impact on extent of coloration and bi-functionalization of the final products. The extent of surface modification as well degree of fixation and immobilization of the used coloring and functional agents as well as the durability to wash were confirmed by SEM & EDX analysis and washing test, respectively.
Elevated fecal levels of the inflammatory biomarker calprotectin in early systemic sclerosis
Authors: Hamberg Viggo , Wallman Johan K. , Mogard Elisabeth , Lindqvist Elisabet , Olofsson Tor , Andréasson Kristofer
Published: December 2022

Knowledge on gastrointestinal manifestations in early systemic sclerosis (SSc) is limited. We have investigated gastrointestinal inflammation in SSc at the time of diagnosis using the inflammatory biomarker Fecal calprotectin (F-cal). Consecutive patients with suspected SSc were characterized in relation to the 2013 classification criteria for SSc and classified as SSc or SSc-like disease. F-cal levels were measured with a polyclonal ELISA (Calpro A/S, Lysaker, Norway) and levels above 50 µg/g were considered elevated. F-cal levels were compared to those of control subjects without rheumatic disease. Of 137 patients with suspected SSc, 92 were classified as SSc and 45 as SSc-like disease. Median (interquartile range) disease duration among the SSc participants was 2.5 (1.2, 4.6) years. A substantial proportion of participants classified as SSc (35/92, 38%) and SSc-like disease (14/45, 31%) exhibited elevated F-cal compared to the control group (3/41, 7.3%; p < 0.001 and p = 0.007, respectively). Elevated F-cal was associated with proton pump inhibitor usage (OR 7.14; 95% CI 2.56–29.93; p < 0.001). We conclude that elevated F-cal is present in a subgroup of patients with SSc at the time of diagnosis, suggesting that that GI inflammation may be present in this patient group early in the disease course. F-cal did not exhibit potential to differentiate SSc from SSc-like disease.
A systematic review of the impact of 7-keto-DHEA on body weight
Authors: Jeyaprakash Nishanthini , Maeder Sara , Janka Heidrun , Stute Petra
Published: December 2022

7-Keto-DHEA has been commercially advertised as a dietary supplement to support weight loss. The objective of the present systematic review it to summarize the evidence supporting the use of 7-keto-DHEA in overweight and obese population. The systematic search was conducted in Medline, Embase, Cochrane Library, CINAHL, Web of Science, Scopus, ICTRP, and ClinicalTrials.gov. Additionally, reference lists of eligible studies were considered, and authors of relevant studies were contacted. Two authors independently screened the studies against the inclusion criteria and assessed their risk of bias. In total, 4 out of 686 studies were included in the review. They all held a low risk of bias. Half of them showed a significant reduction in body weight. One study found a decrease in body fat percentage and another one reported a decrease in BMI. Two studies stated an increase in resting metabolic rate. No serious adverse effects were reported. Various possible mechanisms in favor of weight loss are discussed; however, with the evidence currently available, no clear answer can be given regarding 7-keto-DHEA and weight loss. Further studies need to be conducted to clarify the efficacy and safety of this drug before it can be recommended for therapeutic use.
The longitudinal association between working from home and musculoskeletal pain during the COVID-19 pandemic
Authors: Bosma Esmee , Loef Bette , van Oostrom Sandra H. ,   Lifelines Corona Research Initiative, Proper Karin I.
Published: December 2022

Objective

This study investigates the associations between working from home and the presence of MSP during the COVID-19 pandemic. Working from home often involves a lot of sedentary computer screen work and the home working environment might not be optimally equipped, which can lead to health problems, including musculoskeletal pain (MSP).

Methods

Longitudinal data from 16 questionnaire rounds of the Lifelines COVID-19 cohort during the first year of the COVID-19 pandemic (March 2020-February 2021) were used. In total, 40,702 Dutch workers were included. In every round, participants reported whether they worked on location, from home, or hybrid. Logistic Generalized Estimating Equations were used to study the association of work situation with the presence of MSP and the presence of severe MSP.

Results

Working from home was associated with higher risks of having MSP in the lower back (OR: 1.05, 95% CI 1.02–1.08), in the upper back (OR: 1.24, 95% CI 1.18–1.31), and in the neck, shoulder(s) and/or arm(s) (OR: 1.18, 95% CI 1.13–1.22). Hybrid working was associated with higher risks of having pain in the upper back (OR: 1.09, 95% CI 1.02–1.17) and in the neck, shoulder(s) and/or arm(s) (OR: 1.14, 95% CI 1.09–1.20). Both home and hybrid workers had higher risks of severe MSP in the different body areas.

Conclusion

Home workers, and to a smaller extent hybrid workers, had higher risks of having MSP than location workers during the first year of the COVID-19 pandemic. The results indicate the importance of measures to prevent MSP in future policies involving working from home.
A single-institution retrospective analysis of intraoperative radiation boost during breast-conservation treatment for breast cancer
Authors: Hochhertz Franka , Hass Peter , Röllich Burkard , Ochel Hans-Joachim , Gawish Ahmed
Published: December 2022

Background

As part of a breast-conservation strategy for breast cancer, there are presently no data from randomized controlled studies on the use of intraoperative radiation (IORT) as a tumor bed boost. The effectiveness and safety of IORT as a boost therapy at a tertiary cancer center were retrospectively reviewed in this study.

Methods

Patients had breast-conserving surgery from 2012 to 2016 that included staging of the axillary lymph nodes, a single dose of 20 Gy IORT with 50-kV photons, whole-breast irradiation (WBI), and (neo-)adjuvant systemic treatment (if applicable). During the follow-up patients were monitored for the assessment of acute and late toxicities (using the Common Terminology Criteria for Adverse Events version 4.03). Results included ipsilateral (IBTR), contralateral (CBE), and distant metastasis-free (DMFS) breast progression-free survival, as well as overall survival (OS).

Results

The 68 patients had a median follow-up of 91.5 months (with a range of 9–125). Most patients (n = 51) had T1 disease and were clinically node negative. Only a small number of individuals had triple negative or high-grade illness. The majority of patients had sentinel node biopsy, and three (4.4%) had to have their tumors removed again since their original margins were positive. Finally, there were no distinct tumor bed margins. Neoadjuvant chemotherapy was administered to ten (14.7%). The median duration from BCS to WBI was 54.5 days, and conventionally fractionated WBI was used to accomplish WBI most frequently (n = 57, 96.6%). IORT was administered in a single 20 Gy dosage. 50 Gy was the median WBI dosage (range 40.05–50.4 Gy). There were no grade 4 adverse events for any patients in. Toxicities following surgery were minimal. There were only one patient with grade 3 toxicity (radiation dermatitis) to observe. Five tumor bed recurrences and two contralateral breast incident each occurred.

Conclusion

This work adds to the preliminary evidence already in the literature and supports the use of IORT in boost settings. When randomized trials like TARGIT-B are eventually published, these hopeful findings should be prospectively evaluated.
Hypergraph-based importance assessment for binary classification data
Authors: Misiorek Pawel , Janowski Szymon
Published: December 2022

We present a novel hypergraph-based framework enabling an assessment of the importance of binary classification data elements. Specifically, we apply the hypergraph model to rate data samples’ and categorical feature values’ relevance to classification labels. The proposed Hypergraph-based Importance ratings are theoretically grounded on the hypergraph cut conductance minimization concept. As a result of using hypergraph representation, which is a lossless representation from the perspective of higher-order relationships in data, our approach allows for more precise exploitation of the information on feature and sample coincidences. The solution was tested using two scenarios: undersampling for imbalanced classification data and feature selection. The experimentation results have proven the good quality of the new approach when compared with other state-of-the-art and baseline methods for both scenarios measured using the average precision evaluation metric.
Ready for Failure? Irrational Beliefs, Perfectionism and Mental Health in Male Soccer Academy Players
Authors: Jordana Anna , Ramis Yago , Chamorro Jose L. , Pons Joan , Borrueco Marta , De Brandt Koen , Torregrossa Miquel
Published: December 2022

Since Junior-to-Senior Transition (JST) is only considered successful when soccer players become professionals, many junior athletes must cope with failure, and their sporting careers and mental health may be at risk. Therefore, the objectives of this study are to (a) identify different career expectancies of male soccer academy players, and (b) describe irrational beliefs, perfectionism and mental health levels associated with different career expectancies, identifying risk factors in the JST. A total of 515 male soccer players between 14 and 19 years old (M = 16.7; SD = 1.6) who played in Spanish professional youth academies during the 2020–2021 season, answered questionnaires on sports career model, beliefs, perfectionism and mental health (i.e., iPBI, MPS-2 and GHQ-12). The results suggest that the number of juniors who aspire to be professionals (57%) far exceeds the number of players who become professionals (10%; Dugdale in Scandinavian Journal of Medicine & Science in Sports 31:73–84, 2021). Also, results show that this population presents high levels of demandingness (M = 5.5), low frustration tolerance (M = 5.2), self-organization (M = 5.2) and social functioning (M = 5.5), and low scores on depreciation (M = 2.6) and loss of confidence and self-esteem (M = 2.4). In a more detailed way, the results are compared according to expectancies. These academies are usually environments where success and failure are antagonistic concepts, and where perfectionism and irrational beliefs are normalized and integrated among all members of this context. However, the possible maladaptive effects put their mental health at risk. With the aim of rationalizing the concepts of success and failure and protecting their mental health, especially those who will not become professionals, this study proposes a new route based on the REBT philosophy and ARRC technique.
Application of gamma spectrometry for the characterization and influence of the archeological works of an archaeological site
Authors: Expósito-Suárez V. M. , Suárez-Navarro J. A. , Vacas-Arquero P. , Caro A.
Published: December 2022

The purpose of this study was the use of gamma spectrometry to characterize the archaeological site of Molina de Aragón, located in the province of Guadalajara in Spain. To do so, a set of samples with different historical influences have been selected. The samples were analyzed by gamma spectrometry with HPGe detectors, and by X-ray fluorescence, to know their chemical composition. The statistical study of the activity concentration of radionuclides from the natural radioactive series, 40K and 137Cs, was carried out using box-and-whisker plots, cluster analysis and principal component analysis (PCA). Likewise, the in-situ effective dose rates and the ones determined from the activity concentrations obtained by gamma spectrometry were evaluated to verify sampling reproducibility. The results obtained made it possible to classify the areas of Jewish and Christian influence based on the relationships between 232Th and 238U series and the possible influence of the archaeological works carried out in the study area. The least altered areas could also be identified from the activity concentrations of 137Cs and 210Pbex. Activity concentrations and effective dose rates were equivalent to the natural radioactive background of the Iberian Peninsula. PCA showed a correlation between Fe2O3, Al2O3 y ZrO2 and the natural radioactive series of thorium and uranium.
Preoperative angiographic considerations and neurological outcome after surgical treatment of intradural spinal hemangioblastoma: a multicenter retrospective case series
Authors: Butenschoen Vicki M. , Schwendner Maximilian , Hubertus Vanessa , Onken Julia , Koegl Nikolaus , Mohme Theresa , Maurer Stefanie , Boeckh-Behrens Tobias , Eicker Sven O. , Thomé Claudius , Vajkoczy Peter , Czabanka Marcus , Meyer Bernhard , Wostrack Maria
Published: December 2022

Purpose

Intradural spinal hemangioblastomas are rare highly hypervascularized benign neoplasms. Surgical resection remains the treatment of choice, with a significant risk of postoperative neurological deterioration. Due to the tumor infrequency, scientific evidence is scarce and limited to case reports and small case series.

Methods

We performed a retrospective multicenter study including five high-volume neurosurgical centers analyzing patients surgically treated for spinal hemangioblastomas between 2006 and 2021. We assessed clinical status, surgical data, preoperative angiograms, and embolization when available. Follow-up records were analyzed, and logistic regression performed to assess possible risk factors for neurological deterioration.

Results

We included 60 patients in Germany and Austria. Preoperative angiography was performed in 30% of the cases; 10% of the patients underwent preoperative embolization. Posterior tumor location and presence of a syrinx favored gross total tumor resection (93.8% vs. 83.3% and 97.1% vs. 84%). Preoperative embolization was not associated with postoperative worsening. The clinical outcome revealed a transient postoperative neurological deterioration in 38.3%, depending on symptom duration and preoperative modified McCormick grading, but patients recovered in most cases until follow-up.

Conclusion

Spinal hemangioblastoma patients significantly benefit from early surgical treatment with only transient postoperative deterioration and complete recovery until follow-up. The performance of preoperative angiograms remains subject to center disparities.
Evaluating recent methods to overcome spatial confounding
Authors: Urdangarin Arantxa , Goicoa Tomás , Ugarte María Dolores
Published: December 2022

The concept of spatial confounding is closely connected to spatial regression, although no general definition has been established. A generally accepted idea of spatial confounding in spatial regression models is the change in fixed effects estimates that may occur when spatially correlated random effects collinear with the covariate are included in the model. Different methods have been proposed to alleviate spatial confounding in spatial linear regression models, but it is not clear if they provide correct fixed effects estimates. In this article, we consider some of those proposals to alleviate spatial confounding such as restricted regression, the spatial+ model, and transformed Gaussian Markov random fields. The objective is to determine which one provides the best estimates of the fixed effects. Dowry death data in Uttar Pradesh in 2001, stomach cancer incidence data in Slovenia in the period 1995–2001 and lip cancer incidence data in Scotland between the years 1975–1980 are analyzed. Several simulation studies are conducted to evaluate the performance of the methods in different scenarios of spatial confounding. Results reflect that the spatial+ method seems to provide fixed effects estimates closest to the true value although standard errors could be inflated.
Defect-based fatigue model for additive manufacturing
Authors: Afazov Shukri , Serjouei Ahmad , Hickman Graham J. , Mahal Rajan , Goy Damien , Mitchell Iain
Published: December 2022

A novel defect-based fatigue model for the prediction of S–N (stress versus number of cycles) data points and curves is proposed in this paper. The model is capable of predicting the material fatigue performance based on defect size and location from the surface. A defect factor was introduced and obtained based on notch theory, which considers the notch sensitivity of the material as well as the stress concentration obtained using the finite element method. A newly developed equation was applied to represent the relationship between the defect factor, defect size and defect location from the surface. AlSi10Mg samples were manufactured using laser powder bed fusion, and then machined. The samples were tested under rotational bending cyclic loading until failure. The failed samples were analysed using scanning electron microscopy and it was found that cracks initiated from defects located at the surface. The measured defect size and location were used to predict the number of cycles for an applied stress using the proposed defect-based fatigue model. This model was validated by comparing the predicted and experimentally obtained S–N data. The proposed model has the potential to be applied to component-level fatigue assessment and integrated into industrial quality assurance workflows. For instance, defects can be measured for each produced industrial component and directly assessed against fatigue performance using the developed defect-based fatigue model. This could enable the rapid approval and certification of future additively manufactured industrial components, which can unleash the commercial potential of additive manufacturing for light-weight multi-functional component designs.
A modified common midpoint approach for GPR radars
Authors: Picchi Davide , Brell-Çokcan Sigrid
Published: December 2022

Ground Penetrating Radar (GPR) plays an important role among the non-destructive methods used to analyze, measure and collect data from pavement layers, building structures and archaeological sites. A GPR device consists of a radar able to get an image, technically called radargram, of the subsurface. Due to the decreasing costs of calculation power, it is now possible to analyze and interpret radargrams more efficiently than in past. While technological advancements and improvements in the post-processing of data have increased the power of this process, it is also important to consider survey technique as a key factor in nondestructive testing. The aim of this paper is to propose a modification of a well-known survey technique called Common Mid-Point (CMP). The conventional CMP survey technique requires that the transmitter and receiver of the GPR device be physically separated to survey a site. This provides the benefit of determining the speed of light in the host medium from the slant of the hyperbola reflection of a buried target. The CMP process unifies the inspection technology into a single device, making the use of GPR more accessible to robots on construction sites. The method documented in this paper is based on a mathematical model for adapting the conventional CMP for conventional GPR radar devices, in which transmitter and receiver cannot be separated physically.
On the rub-impact force, bifurcations analysis, and vibrations control of a nonlinear rotor system controlled by magnetic actuator integrated with PIRC-control algorithm
Authors: Saeed Nasser A. , Omara Osama M. , Sayed M. , Awrejcewicz Jan , Mohamed Mohamed S.
Published: December 2022

This article presents the Proportional Integral Resonant Controller (PIRC-controller) as a novel control strategy to suppress the lateral vibrations and eliminate nonlinear bifurcation characteristics of a vertically supported rotor system. The proposed control algorithm is incorporated into the rotor system via an eight-pole electromagnetic actuator. The control strategy is designed such that the control law (PIRC-controller) is employed to generate eight different control currents depending on the air-gap size between the rotor and the electromagnetic poles. Then, the generated electrical currents are utilized to energize the magnetic actuator to apply controllable electromagnetic attractive forces to suppress the undesired lateral vibrations of the considered rotor system. According to the suggested control strategy, the whole system can be represented as a mathematical model using classical mechanics' principle and electromagnetic theory, in which, the rub-impact force between the rotor and the stator is included in the derived model. Then, the obtained discrete dynamical model is analyzed using perturbation techniques and validated numerically through bifurcation diagrams, frequency spectrums, Poincare maps, time responses, and steady-state whirling orbit. The obtained results illustrate that the proposed control algorithm can mitigate the nonlinear vibration and eliminate the catastrophic bifurcations of the rotor system when the control gains are designed optimally. In addition, the system dynamics are analyzed when the rub-impact occurrence between the rotor and the pole housing is unavoidable. The acquired results revealed that the system may perform periodic-1, periodic-n, or quasiperiodic motion with one of two oscillation modes depending on both the impact stiffness coefficient and the dynamic friction coefficient.

Article Highlights

Nonlinearity dominates the uncontrolled rotor response, where it suffers from the jump phenomenon and multiple solutions.

The proposed controller forces the Jeffcott rotor to respond as a linear system with small oscillation amplitudes.

The rotor oscillates with full-annular-rub or partial-rub-impact mode when rub-impact occurs between the rotor and stator.
Introducing SNAP: a novel pedal-assisted electric ultralight vehicle
Authors: Passarella Francesco , Mantriota Giacomo , Reina Giulio
Published: December 2022

Innovation in transportation and mobility is central to sustainable development. There is a widespread awareness that society would benefit if transportation became more sustainable, promoting economic growth while respecting the environment. This paper introduces SNAP, a four-wheel pedal-assisted electric vehicle that represents a new concept in sustainable mobility towards filling the gap between bicycle and automobile. The choice of the architecture for the hybrid powertrain where the driver pedals are assisted with an electric motor is discussed along with the experimental analysis of the power loss associated with the single components of the transmission. In turn, this knowledge allows the overall quadricycle performance to be evaluated in terms of maximum speed, efficiency, and travel range at varying operating conditions that include vehicle load, road slope, and gear change. It is shown that SNAP can be a promising answer to address the problem of sustainable and safe micro mobility of persons and goods in urban settings.
The Giant Ionospheric Depletion on 15 January 2022 Around the Hunga Tonga‐Hunga Ha'apai Volcanic Eruption
Authors: He Jianhui , Astafyeva Elvira , Yue Xinan , Ding Feng , Maletckii Boris
Published: December 2022

The 15 January 2022 Tonga eruption seemed to have caused a strong depletion in the ionospheric electron density. However, the eruption occurred during a moderate geomagnetic storm, so that the depletion could be a local negative effect of the storm. In this work, for the first time, we analyze this depletion and discuss relative contributions of the eruption and the storm through measurements of GNSS‐derived vertical total electron content (VTEC), O/N2 ratio by TIMED/GUVI, ion density and temperature by ICON/IVM, and simulations by Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM). We show that shortly after the eruption onset the VTEC in the vicinity of the volcano dropped by ∼80%–95% below the quiet‐time values. The depletion extended up to 4,000 km away from the volcano and lasted for ∼16 hr, that is, until local morning hours. Our results suggest that the depletion was initially caused by the eruption (60%–75% negative deviation) and was further reinforced by the storm, by at least 20%. Spatially, only ∼1,500 km could be attributed to the eruption. This study provides a good illustration of understanding the contributions of forcings from above and below to the ionosphere.
A flexible neural implant with ultrathin substrate for low-invasive brain–computer interface applications
Authors: Guo Zhejun , Wang Fang , Wang Longchun , Tu Kejun , Jiang Chunpeng , Xi Ye , Hong Wen , Xu Qingda , Wang Xiaolin , Yang Bin , Sun Bomin , Lin Zude , Liu Jingquan
Published: December 2022

Implantable brain–computer interface (BCI) devices are an effective tool to decipher fundamental brain mechanisms and treat neural diseases. However, traditional neural implants with rigid or bulky cross-sections cause trauma and decrease the quality of the neuronal signal. Here, we propose a MEMS-fabricated flexible interface device for BCI applications. The microdevice with a thin film substrate can be readily reduced to submicron scale for low-invasive implantation. An elaborate silicon shuttle with an improved structure is designed to reliably implant the flexible device into brain tissue. The flexible substrate is temporarily bonded to the silicon shuttle by polyethylene glycol. On the flexible substrate, eight electrodes with different diameters are distributed evenly for local field potential and neural spike recording, both of which are modified by Pt-black to enhance the charge storage capacity and reduce the impedance. The mechanical and electrochemical characteristics of this interface were investigated in vitro. In vivo, the small cross-section of the device promises reduced trauma, and the neuronal signals can still be recorded one month after implantation, demonstrating the promise of this kind of flexible BCI device as a low-invasive tool for brain–computer communication.
Transparent planar solar absorber for winter thermal management
Authors: Asad Muhammad Saad , Alam M. Z.
Published: December 2022

Indoor heating during winters accounts for a significant portion of energy consumed by buildings in regions of cold climate. Development of transparent coatings for windows that efficiently harvest solar energy can play a major role in reducing energy consumption and fuel costs incurred for winter heating. In recent years, there has been a great research effort towards designing transparent solar absorber coatings using nanophotonic structures. The potential of coatings based on planar multilayer structures, however, has received very little attention. In this work we investigate the performance of planar multilayer thin films using low-cost materials for design of transparent solar absorber window coatings. Our study led to the proposal of two planar multilayer designs. Simulation results predict that an increase in surface temperature by 27 K and 25 K, while maintaining mean visible transmittance of over 50% is possible using these designs. These results illustrate the great promise planar multilayer structures hold for winter thermal management of buildings.
Humoral and cellular immune responses to Lassa fever virus in Lassa fever survivors and their exposed contacts in Southern Nigeria
Authors: Ugwu Chinedu , Olumade Testimony , Nwakpakpa Ebenezer , Onyia Venatius , Odeh Elizabeth , Duruiheoma Rosemary Ogonna , Ojide Chiedozie K. , Eke Matthew Afam , Nwafor Ifeanyi Emmanuel , Chika-Igwenyi Nneka , Abu Augustine M. , Azuogu Benedict , Ajayi Nnennaya , Ogah Emeka , Ayodeji Oluwafemi , Abejegah Chukwuyem , Adedosu Nelson , Oyejide Nicholas , Abah Sylvester , Omidele Abiola , Ingbian Winifred , Osoba Emmanuel , Eromon Philomena , Oluniyi Paul , Ogunsanya Olusola , Happi Anise , Otuh Patricia , Nadesalingam Angalee , Carnell George , Krause Nina , Aguinam Ernest , Kinsley Rebecca , Storisteanu Daniel Matthew L. , Tonks Paul , Nelson Diana , McAlister Carley , Boisen Matthew , Garry Robert , Wright Edward , Temperton Nigel , Frost Simon , Heeney Jonathan Luke , Happi Christian
Published: December 2022

Elucidating the adaptive immune characteristics of natural protection to Lassa fever (LF) is vital in designing and selecting optimal vaccine candidates. With rejuvenated interest in LF and a call for accelerated research on the Lassa virus (LASV) vaccine, there is a need to define the correlates of natural protective immune responses to LF. Here, we describe cellular and antibody immune responses present in survivors of LF (N = 370) and their exposed contacts (N = 170) in a LASV endemic region in Nigeria. Interestingly, our data showed comparable T cell and binding antibody responses from both survivors and their contacts, while neutralizing antibody responses were primarily seen in the LF survivors and not their contacts. Neutralizing antibody responses were found to be cross-reactive against all five lineages of LASV with a strong bias to Lineage II, the prevalent strain in southern Nigeria. We demonstrated that both T cell and antibody responses were not detectable in peripheral blood after a decade in LF survivors. Notably LF survivors maintained high levels of detectable binding antibody response for six months while their contacts did not. Lastly, as potential vaccine targets, we identified the regions of the LASV Glycoprotein (GP) and Nucleoprotein (NP) that induced the broadest peptide-specific T cell responses. Taken together this data informs immunological readouts and potential benchmarks for clinical trials evaluating LASV vaccine candidates.
Three-dimensional muon imaging of cavities inside the Temperino mine (Italy)
Authors: Borselli Diletta , Beni Tommaso , Bonechi Lorenzo , Bongi Massimo , Brocchini Debora , Casagli Nicola , Ciaranfi Roberto , Cimmino Luigi , Ciulli Vitaliano , D’Alessandro Raffaello , Dini Andrea , Frosin Catalin , Gigli Giovanni , Gonzi Sandro , Guideri Silvia , Lombardi Luca , Nocentini Massimiliano , Saracino Giulio
Published: December 2022

Muon radiography (muography) is an imaging technique based on atmospheric muon absorption in matter that allows to obtain two and three-dimensional images of internal details of hidden objects or structures. The technique relies on atmospheric muon flux measurements performed around and underneath the object under examination. It is a non-invasive and passive technique and thus can be thought of as a valid alternative to common prospecting techniques used in archaeological, geological and civil security fields. This paper describes muon radiography measurements, in the context of archaeological and geological studies carried out at the Temperino mine (LI, Tuscany, Italy), for the search and three-dimensional visualisation of cavities. This mine has been exploited since Etruscan times until recently (1973), and is now an active tourist attraction with public access to the tunnels. Apart from the archaeological interest, the importance of mapping the cavities within this mine lies in identifying the areas where the extraction ores were found and also in the safety issues arising from the tourist presence inside the mine. The three-dimensional imaging is achieved with two different algorithms: one involving a triangulation of two or more measurements at different locations; the other, an innovative technique used here for the first time, is based on the back-projections of reconstructed muon tracks. The latter requires only a single muographic data tacking and is to be preferred in applications where more than one site location can be difficult to access. Finally the quality of the three-dimensional muographic imaging was evaluated by comparing the results with the laser scan profiles obtained for some known cavities within the Temperino mine.
Identifying cause-and-effect relationships of manufacturing errors using sequence-to-sequence learning
Authors: Reimer Jeff , Wang Yandong , Laridi Sofiane , Urdich Juergen , Wilmsmeier Sören , Palmer Gregory
Published: December 2022

In car-body production the pre-formed sheet metal parts of the body are assembled on fully-automated production lines. The body passes through multiple stations in succession, and is processed according to the order requirements. The timely completion of orders depends on the individual station-based operations concluding within their scheduled cycle times. If an error occurs in one station, it can have a knock-on effect, resulting in delays on the downstream stations. To the best of our knowledge, there exist no methods for automatically distinguishing between source and knock-on errors in this setting, as well as establishing a causal relation between them. Utilizing real-time information about conditions collected by a production data acquisition system, we propose a novel vehicle manufacturing analysis system, which uses deep learning to establish a link between source and knock-on errors. We benchmark three sequence-to-sequence models, and introduce a novel composite time-weighted action metric for evaluating models in this context. We evaluate our framework on a real-world car production dataset recorded by Volkswagen Commercial Vehicles. Surprisingly we find that 71.68% of sequences contain either a source or knock-on error. With respect to seq2seq model training, we find that the Transformer demonstrates a better performance compared to LSTM and GRU in this domain, in particular when the prediction range with respect to the durations of future actions is increased.
An observability and detectability analysis for non-linear uncertain CSTR model of biochemical processes
Authors: Czyżniewski Mateusz , Łangowski Rafał
Published: December 2022

The problem of proving observability/detectability properties for selected non-linear uncertain model of biochemical processes has been addressed in this paper. In particular, the analysis of observability/detectability in the face of parametric and unstructured uncertainty in system dynamics transformed into unknown inputs, and unknown initial conditions has been performed. Various sets of system measured outputs were taken into account during the research. The considered biochemical processes were modelled as a continuous stirred tank reactor with the microbial growth reaction and microbial mortality with the aggregated substrate and biomass concentrations in aerobic phase. Classical tools based on differential geometry and the method of indistinguishable state trajectories (indistinguishable dynamics) were used to verify the properties of the system. The observability/detectability analysis was performed for nine cases covering a wide range of possible combinations of system measured outputs and unknown inputs. The obtained results of are crucial meaning for system state reconstruction (estimation), which involves the synthesis of state observers.
Circularly polarised photoluminescence and electroluminescence of chiral copper(i) dimers based onR/S-2,2′-bis(diphenylphosphino)-1,1′-binaphthalene ligands
Authors: Zhou Yong-Hui , Zhang Ai-Wei , Huang Ru-Jun , Sun Yu-Hang , Chen Zhu-Jun , Zhu Bai-Song , Zheng You-Xuan
Published: December 2022

R/S-(BINAP)2Cu(μ-I2) enantiomer doped films show a high |gPL| factor above 1 × 10−2, while a pioneering work of CP-OLEDs based on chiral Cu(i) enantiomers exhibited a high EQE of 21.7% and |gEL| factors of around 3.0 × 10−3.
Hierarchical multi‐agent reinforcement learning for multi‐aircraft close‐range air combat
Authors: Kong Wei‐ren , Zhou De‐yun , Du Yong‐jie , Zhou Ying , Zhao Yi‐yang
Published: December 2022

The close‐range autonomous air combat has gained significant attention from researchers involved in applications related to artificial intelligence (AI). A majority of the previous studies on autonomous air combat were focused on one‐on‐one air combat scenarios, however, the modern air combat is mostly conducted in formations. With regard to the aforementioned factors, a novel hierarchical maneuvering control architecture is introduced that is applied to the multi‐aircraft close‐range air combat scenario, which can handle air combat scenarios with variable‐size formation. Subsequently, three air combat sub‐tasks are designed, and recurrent soft actor‐critic (RSAC) algorithm combined with competitive self‐play (SP) is incorporated to learn the sub‐strategies. A novel hierarchical multi‐agent reinforcement learning (HMARL) algorithm is proposed to obtain the high‐level strategy for target and sub‐strategy selection. The training performance of the training algorithm of sub‐strategies and high‐level strategy in different air combat scenarios is evaluated. The obtained strategies are analyzed and it is found that the formations exhibit effective cooperative behavior in symmetric and asymmetric scenarios. Finally, the ideas of engineering implementation of the maneuvering control architecture are given. The study provides a solution for future multi‐aircraft autonomous air combat.
Performance evaluation of a new modular split‐tooth permanent magnet‐assisted switched reluctance motor
Authors: Radmanesh Hamid , Farmahini Farahani Ehsan
Published: December 2022

This study elaborates upon a new modular split‐tooth permanent magnet‐assisted switched reluctance motor (MSTPM‐SRM). In the proposed topology, the stator comprises six modular E‐cores in which the middle poles are split into two teeth. Two permanent magnets (PMs) are placed between each module's middle and side poles. Primarily, the proposed topology is introduced. Next, the principle of operation of the proposed topology are elucidated, and the magnetic equivalent circuit analysis is adopted in order to validate the operational basics. It is proved that the embedded PMs significantly increase the air‐gap's flux density and adjusts the poles' flux density. The flux density distributions, static, and steady‐state characteristics of the proposed MSTPM‐SRM motor and its PMless counterpart are extracted by utilising 2‐D finite element analysis. It is illustrated that the average torque of the proposed MSTPM‐SRM is dramatically increased compared to its PMless counterpart, especially at high excitation currents. Furthermore, the cogging torque analysis is done and it is shown that the proposed structure has approximately zero cogging torque. Finally, a prototyping version of the proposed motor is fabricated, and the experimental results are elicited. It is shown that the experimental results endorse the simulation results.
Overview of collaborative response between the power distribution network and urban transportation network coupled by electric vehicle cluster under unconventional events
Authors: Wang Ying , Xu Yin , He Jinghan , Lee Seung Jae
Published: December 2022

With the rapid development of electric vehicles, they have become an important part of urban distribution and transportation networks. The power distribution network and transportation network are coupled by electric vehicle clusters and integrated through strong interactions, creating a coupled system. This paper presents the study on their collaborative responses is essential to reduce losses and improve urban resilience during unconventional events. First, the multidimensional and deep‐level time‐varying closed‐loop coupling effects of the power distribution network and urban transportation network coupled by electric vehicle clusters are analysed under unconventional events. Second, based on the different scales of unconventional events, a summary of relevant studies is made on the collaborative response strategies of the coupled system to urban local power outages and large‐scale blackouts following unconventional events. Finally, future research directions are discussed.