bluuebunny/crossref_metadata_2025 huggingface dataset:
Tropism of SARS-CoV-2 for human cortical astrocytes
Authors: Andrews Madeline G. , Mukhtar Tanzila , Eze Ugomma C. , Simoneau Camille R. , Ross Jayden , Parikshak Neelroop , Wang Shaohui , Zhou Li , Koontz Mark , Velmeshev Dmitry , Siebert Clara-Vita , Gemenes Kaila M. , Tabata Takako , Perez Yonatan , Wang Li , Mostajo-Radji Mohammed A. , de Majo Martina , Donohue Kevin C. , Shin David , Salma Jahan , Pollen Alex A. , Nowakowski Tomasz J. , Ullian Erik , Kumar G. Renuka , Winkler Ethan A. , Crouch Elizabeth E. , Ott Melanie , Kriegstein Arnold R.
Published: July 2022

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) readily infects a variety of cell types impacting the function of vital organ systems, with particularly severe impact on respiratory function. Neurological symptoms, which range in severity, accompany as many as one-third of COVID-19 cases, indicating a potential vulnerability of neural cell types. To assess whether human cortical cells can be directly infected by SARS-CoV-2, we utilized stem-cell-derived cortical organoids as well as primary human cortical tissue, both from developmental and adult stages. We find significant and predominant infection in cortical astrocytes in both primary tissue and organoid cultures, with minimal infection of other cortical populations. Infected and bystander astrocytes have a corresponding increase in inflammatory gene expression, reactivity characteristics, increased cytokine and growth factor signaling, and cellular stress. Although human cortical cells, particularly astrocytes, have no observable ACE2 expression, we find high levels of coronavirus coreceptors in infected astrocytes, including CD147 and DPP4. Decreasing coreceptor abundance and activity reduces overall infection rate, and increasing expression is sufficient to promote infection. Thus, we find tropism of SARS-CoV-2 for human astrocytes resulting in inflammatory gliosis-type injury that is dependent on coronavirus coreceptors.
Sequential rescue and repair of stalled and damaged ribosome by bacterial PrfH and RtcB
Authors: Tian Yannan , Zeng Fuxing , Raybarman Adrika , Fatma Shirin , Carruthers Amy , Li Qingrong , Huang Raven H.
Published: July 2022

RtcB is involved in transfer RNA (tRNA) splicing in archaeal and eukaryotic organisms. However, most RtcBs are found in bacteria, whose tRNAs have no introns. Because tRNAs are the substrates of archaeal and eukaryotic RtcB, it is assumed that bacterial RtcBs are for repair of damaged tRNAs. Here, we show that a subset of bacterial RtcB, denoted RtcB2 herein, specifically repair ribosomal damage in the decoding center. To access the damage site for repair, however, the damaged 70S ribosome needs to be dismantled first, and this is accomplished by bacterial PrfH. Peptide-release assays revealed that PrfH is only active with the damaged 70S ribosome but not with the intact one. A 2.55-Å cryo-electron microscopy structure of PrfH in complex with the damaged 70S ribosome provides molecular insight into PrfH discriminating between the damaged and the intact ribosomes via specific recognition of the cleaved 3′-terminal nucleotide. RNA repair assays demonstrated that RtcB2 efficiently repairs the damaged 30S ribosomal subunit but not the damaged tRNAs. Cell-based assays showed that the RtcB2–PrfH pair reverse the damage inflicted by ribosome-specific ribotoxins in vivo. Thus, our combined biochemical, structural, and cell-based studies have uncovered a bacterial defense system specifically evolved to reverse the lethal ribosomal damage in the decoding center for cell survival.
Quantifying the hydrodynamic contribution to electrical transport in non-Brownian suspensions
Authors: Lin Han , Majji Madhu V. , Cho Noah , Zeeman John R. , Swan James W. , Richards Jeffrey J.
Published: July 2022

Electrical transport in semiconducting and metallic particle suspensions is an enabling feature of emerging grid-scale battery technologies. Although the physics of the transport process plays a key role in these technologies, no universal framework has yet emerged. Here, we examine the important contribution of shear flow to the electrical transport of non-Brownian suspensions. We find that these suspensions exhibit a strong dependence of the transport rate on the particle volume fraction and applied shear rate, which enables the conductivity to be dynamically changed by over 10
7
decades based on the applied shear rate. We combine experiments and simulations to conclude that the transport process relies on a combination of charge and particle diffusion with a rate that can be predicted using a quantitative physical model that incorporates the self-diffusion of the particles.
Spatiotemporal dynamics of calcium signals during neutrophil cluster formation
Authors: Khazen Roxana , Corre Béatrice , Garcia Zacarias , Lemaître Fabrice , Bachellier-Bassi Sophie , d’Enfert Christophe , Bousso Philippe
Published: July 2022

Neutrophils form cellular clusters or swarms in response to injury or pathogen intrusion. Yet, intracellular signaling events favoring this coordinated response remain to be fully characterized. Here, we show that calcium signals play a critical role during mouse neutrophil clustering around particles of zymosan, a structural fungal component. Pioneer neutrophils recognizing zymosan or live
Candida albicans
displayed elevated calcium levels. Subsequently, a transient wave of calcium signals in neighboring cells was observed followed by the attraction of neutrophils that exhibited more persistent calcium signals as they reached zymosan particles. Calcium signals promoted LTB4 production while the blocking of extracellular calcium entry or LTB4 signaling abrogated cluster formation. Finally, using optogenetics to manipulate calcium influx in primary neutrophils, we show that calcium signals could initiate recruitment of neighboring neutrophils in an LTB4-dependent manner. Thus, sustained calcium responses at the center of the cluster are necessary and sufficient for the generation of chemoattractive gradients that attract neutrophils in a self-reinforcing process.
Dynamic calcium signals mediate the feeding response of the carnivorous sundew plant
Authors: Procko Carl , Radin Ivan , Hou Charlotte , Richardson Ryan A. , Haswell Elizabeth S. , Chory Joanne
Published: July 2022

Some of the most spectacular examples of botanical carnivory—in which predator plants catch and digest animals presumably to supplement the nutrient-poor soils in which they grow—occur within the Droseraceae family. For example, sundews of the genusDroserahave evolved leaf movements and enzyme secretion to facilitate prey digestion. The molecular underpinnings of this behavior remain largely unknown; however, evidence suggests that prey-induced electrical impulses are correlated with movement and production of the defense hormone jasmonic acid (JA), which may alter gene expression. In noncarnivorous plants, JA is linked to electrical activity via changes in cytoplasmic Ca2+. Here, we find that dynamic Ca2+changes also occur in sundew (Drosera spatulata) leaves responding to prey-associated mechanical and chemical stimuli. Furthermore, inhibition of these Ca2+changes reduced expression of JA target genes and leaf movements following chemical feeding. Our results are consistent with the presence of a conserved Ca2+-dependent JA signaling pathway in the sundew feeding response and provide further credence to the defensive origin of plant carnivory.
Human CD38 regulates B cell antigen receptor dynamic organization in normal and malignant B cells
Authors: Camponeschi Alessandro , Kläsener Kathrin , Sundell Timothy , Lundqvist Christina , Manna Paul T. , Ayoubzadeh Negar , Sundqvist Martina , Thorarinsdottir Katrin , Gatto Mariele , Visentini Marcella , Önnheim Karin , Aranburu Alaitz , Forsman Huamei , Ekwall Olov , Fogelstrand Linda , Gjertsson Inger , Reth Michael , Mårtensson Inga-Lill
Published: July 2022

CD38 is a multifunctional protein expressed on the surface of B cells in healthy individuals but also in B cell malignancies. Previous studies have suggested a connection between CD38 and components of the IgM class B cell antigen receptor (IgM-BCR) and its coreceptor complex. Here, we provide evidence that CD38 is closely associated with CD19 in resting B cells and with the IgM-BCR upon engagement. We show that targeting CD38 with an antibody, or removing this molecule with CRISPR/Cas9, inhibits the association of CD19 with the IgM-BCR, impairing BCR signaling in normal and malignant B cells. Together, our data suggest that CD38 is a new member of the BCR coreceptor complex, where it exerts a modulatory effect on B cell activation upon antigen recognition by regulating CD19. Our study also reveals a new mechanism where α-CD38 antibodies could be a valuable option in therapeutic approaches to B cell malignancies driven by aberrant BCR signaling.
TMEM120A/TACAN inhibits mechanically activated PIEZO2 channels
Authors: Del Rosario John Smith , Gabrielle Matthew , Yudin Yevgen , Rohacs Tibor
Published: July 2022

PIEZO2 channels mediate rapidly adapting mechanically activated currents in peripheral sensory neurons of the dorsal root ganglia (DRG), and they are indispensable for light touch and proprioception. Relatively little is known about what other proteins regulate PIEZO2 activity in a cellular context. TMEM120A (TACAN) was proposed to act as a high threshold mechanically activated ion channel in nociceptive DRG neurons. Here, we find that Tmem120a coexpression decreased the amplitudes of mechanically activated PIEZO2 currents and increased their threshold of activation. TMEM120A did not inhibit mechanically activated PIEZO1 and TREK1 channels and TMEM120A alone did not result in the appearance of mechanically activated currents above background. Tmem120a and Piezo2 expression in mouse DRG neurons overlapped, and siRNA-mediated knockdown of Tmem120a increased the amplitudes of rapidly adapting mechanically activated currents and decreased their thresholds to mechanical activation. Our data identify TMEM120A as a negative modulator of PIEZO2 channel activity, and do not support TMEM120A being a mechanically activated ion channel.
Parameterised population models of transient non-Gaussian noise in the LIGO gravitational-wave detectors
Authors: Ashton Gregory , Thiele Sarah , Lecoeuche Yannick , McIver Jess , Nuttall Laura K
Published: July 2022

The two interferometric LIGO gravitational-wave observatories provide the most sensitive data to date to study the gravitational-wave universe. As part of a global network, they have completed their third observing run in which they observed many tens of signals from merging compact binary systems. It has long been known that a limiting factor in identifying transient gravitational-wave signals is the presence of transient non-Gaussian noise, which reduce the ability of astrophysical searches to detect signals confidently. Significant efforts are taken to identify and mitigate this noise at the source, but its presence persists, leading to the need for software solutions. Taking a set of transient noise artefacts categorised by the GravitySpy software during the O3a observing era, we produce parameterised population models of the noise projected into the space of astrophysical model parameters of merging binary systems. We compare the inferred population properties of transient noise artefacts with observed astrophysical systems from the GWTC2.1 catalogue. We find that while the population of astrophysical systems tend to have near equal masses and moderate spins, transient noise artefacts are typically characterised by extreme mass ratios and large spins. This work provides a new method to calculate the consistency of an observed candidate with a given class of noise artefacts. This approach could be used in assessing the consistency of candidates found by astrophysical searches (i.e. determining if they are consistent with a known glitch class). Furthermore, the approach could be incorporated into astrophysical searches directly, potentially improving the reach of the detectors, though only a detailed study would verify this.
Implantable double-layer pump chamber piezoelectric valveless micropump with adjustable flow rate function
Authors: Shan Jie , Guo Lihua , Ran Penghui , Zhou Zhanwei , Chen Jing , Chen Xueting , Li Jingmin
Published: July 2022

The piezoelectric valveless micropump with the characteristics of precise liquid delivery is widely utilized in the field of biomedicine. However, the improvement of the flow rate of the piezoelectric micropump relies on the increase in size and driving voltage, which hinders its application in the implantable medical field. This article proposes a double-layer chamber valveless piezoelectric micropump, which has the obvious advantages of small size and adjustable flow rate, and is expected to be applied to the treatment of implantable hydrocephalus. The overall size of the micropump is 10 mm × 10 mm × 4 mm, which can be implanted in the cerebral cortex. Combined with polydimethylsiloxane-polyethylene glycol terephthalate bonding technology, the double-layer chamber micropump solves the contradiction between miniaturization and large flow range. The flow rate generated by micropump under low voltage can be adjusted according to the amount of hydrocephalus. In order to reveal the mechanism of increasing the flow rate, the working efficiencies of the microvalve and micropump are studied in this article. The electric-solid-fluid coupling simulation and experimental tests obtained the optimal structural parameters: the divergence angle is 30°, the throat width is 300 μm, and the upper chamber depth is 100 μm. The proposed micropump can achieve the tunable flow rate of 2.16–51.74 μl min−1.
Highly-packed self-assembled graphene oxide film-integrated resistive random-access memory on a silicon substrate for neuromorphic application
Authors: Choi Hyun-Seok , Lee Jihye , Kim Boram , Lee Jaehong , Park Byung-Gook , Kim Yoon , Hong Suck Won
Published: July 2022

Resistive random-access memories (RRAMs) based on metal-oxide thin films have been studied extensively for application as synaptic devices in neuromorphic systems. The use of graphene oxide (GO) as a switching layer offers an exciting alternative to other materials such as metal-oxides. We present a newly developed RRAM device fabricated by implementing highly-packed GO layers on a highly doped Si wafer to yield a gradual modulation of the memory as a function of the number of input pulses. By using flow-enabled self-assembly, highly uniform GO thin films can be formed on flat Si wafers in a rapid and simple process. The switching mechanism was explored through proposed scenarios reconstructing the density change of the sp2 cluster in the GO layer, resulting in a gradual conductance modulation. We analyzed that the current in a low resistance state could flow by tunneling or hopping via clusters because the distance between the sp2 clusters in closely-packed GO layers is short. Finally, through a pattern-recognition simulation with a Modified National Institute of Standards and Technology database, the feasibility of using close-packed GO layers as synapse devices was successfully demonstrated.
Magnetorheological behavior of isotropic silicone rubber-based magnetorheological elastomers under coupled static–dynamic compressive loads
Authors: Zhang Jiangtao , Qiao Yanliang , Zhang Mei , Zhai Pengcheng
Published: July 2022

The primary goal of this work is to test and model the magnetorheological (MR) properties of the isotropic magnetorheological elastomers (MREs) under the coupled static–dynamic compressive loads. Isotropic MREs with different contents of magnetic particles were fabricated based on the silicone elastomer. In order to apply the controllable magnetic field to the MREs and directly measure the viscoelastic force of the deformed MREs during the dynamic tests, an electromagnet with a magnetic flux density of up to 0.9 T was developed and integrated into an electric dynamic test system. The stress–strain hysteresis loops of the produced MREs were experimentally characterized under the dynamic compressive loads coupled with different static pre-strains. Effects of particle content, strain amplitude, static pre-strain and load frequency on the MR properties of the MREs were examined in terms of the characteristics of the hysteresis loops, as well as the MR effects in the storage modulus, loss modulus and pre-stress. The results revealed that irrespective of the applied magnetic field, the deformation behavior of the produced MREs was in an approximate linear viscoelastic state when the strain amplitude was less than 7.5%. Both the absolute and relative MR effects increase with the increasing particle content, and decrease with the increasing strain amplitude. Only the absolute MR effect increases with the increasing pre-strain. While varying the load frequency has almost no effect on the MR effect of the MREs. Furthermore, two empirical models were proposed respectively for predicting the storage modulus and loss modulus of the MREs as functions of the magnetic flux density, particle content, strain amplitude, pre-strain and load frequency. The graphical comparison and quantitative evaluation show that the proposed models can give effective predictions of the storage and loss moduli of the produced MREs under the applied load conditions in this work.
Generalized Dunkl-Schrodinger equations: solvable cases, point transformations, and position-dependent mass systems
Authors: Schulze-Halberg Axel
Published: July 2022

We devise a method for constructing solvable cases of generalized linear Dunkl-Schrödinger equations by means of suitable point transformations. The quantum-mechanical framework pertaining to such equations is discussed, and the particular case of a position-dependent mass scenario is analyzed.
Modeling optimal vaccination strategy for dengue epidemic model: a case study of India
Authors: Dwivedi Ananya , Keval Ram , Khajanchi Subhas
Published: July 2022

Dengue fever is a mosquito-borne infectious disease which is transmitted through Aedes aegypti mosquitoes. It is one of the major global health issues in the tropical and subtropical regions of the world. Its dynamics are very complicated owing to the coupling among multiple transmission pathways and various components in pathogen. Due to absence of proper medicine or vaccination, mathematical modeling plays an important role in understanding the disease dynamics and in designing strategies to control the spread of dengue virus. In this paper, we studied a non-linear vector-host model to investigate the transmission dynamics of dengue virus which can be controlled by vaccination as well as treatment. Analysis of model start with the basic reproduction number

R

0

, when it is less than one, the system become locally asymptotically stable about the virus-free equilibrium point. We calibrated our proposed model corresponding to transmission of dengue virus using real data for six Indian states, namely Tamil Nadu, Kerala, Delhi, Gujarat, Rajasthan and Karnataka by using the least square method. Moreover, we performed normalized forward sensitivity analysis of the basic reproduction number and obtained that mitigating the disease transmission rate of mosquito and human population is the most important factor in achieving dengue control. Finally, an objective functional has been developed to minimize the cost of the vaccination and solved with the aid of the Pontryagin’s Maximum Principle. The implementation of the optimal treatment policy shows a significant reduction of the hospitalized individuals as well as infected individuals. We then performed extensive numerical simulations to validate our theoretical analysis with aid of the estimated model parameters.
Detecting primordial features with LISA
Authors: Fumagalli Jacopo , Pieroni Mauro , Renaux-Petel Sébastien , Witkowski Lukas T.
Published: July 2022

Oscillations in the frequency profile of the stochastic gravitational wave background are a characteristic prediction of small-scale features during inflation. In this paper we present a first investigation of the detection prospects of such oscillations with the upcoming space-based gravitational wave observatory LISA. As a proof of principle, we show for a selection of feature signals that the oscillations can be reconstructed with LISA, employing a method based on principal component analysis. We then perform a Fisher forecast for the parameters describing the oscillatory signal. For a sharp feature we distinguish between the contributions to the stochastic gravitational wave background induced during inflation and in the post-inflationary period, which peak at different frequencies. We find that for the latter case the amplitude of the oscillation is expected to be measurable with < 10% accuracy if the corresponding peak satisfies h
2ΩGW ≳ 10-12-10-11, while for inflationary-era gravitational waves a detection of the oscillations requires a higher peak amplitude of h
2ΩGW, as the oscillations only appear on the UV tail of the spectrum. For a resonant feature the detection prospects with LISA are maximised if the frequency of the oscillation falls into the range ω
log = 4 to 10. Our results confirm that oscillations in the frequency profile of the stochastic gravitational wave background are a worthwhile target for future detection efforts and offer a key for experimentally testing inflation at small scales.
Evaluation of the performance of the CCD236 swept charge devices in lunar orbit using in-flight data
Authors: Jones L.S. , Crews C. , Endicott J. , Holland A.D.
Published: July 2022

India’s Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS) employs 16 CCD236 Swept Charge Devices (SCDs) similar in structure to Charge Coupled Device (CCD) image sensors. The CCD236 permits X-ray detection over a large surface area, intended to improve low flux performance, with simplified control interfaces and improved warm temperature performance. These devices were the subject of ground testing and performance evaluation before flight. Data that was recently made available by the Indian Space Research Organisation (ISRO) has permitted the analysis of the performance of the CLASS SCDs after over a year of operations around the Moon. Of particular interest is the change in device performance and behaviour during transit and in lunar orbit. Preliminary analysis has indicated that device FWHM, representing the aggregate of different noise sources, has increased in line with predictions based on ground irradiation and testing.
Using machine learning for particle identification in ALICE
Authors: Graczykowski Łukasz Kamil , Jakubowska Monika , Deja Kamil Rafał , Kabus Maja
Published: July 2022

Particle identification (PID) is one of the main strengths of the ALICE experiment at the LHC. It is a crucial ingredient for detailed studies of the strongly interacting matter formed in ultrarelativistic heavy-ion collisions. ALICE provides PID information via various experimental techniques, allowing for the identification of particles over a broad momentum range (from around 100 MeV/c to around 50 GeV/c). The main challenge is how to combine the information from various detectors effectively. Therefore, PID represents a model classification problem, which can be addressed using Machine Learning (ML) solutions. Moreover, the complexity of the detector and richness of the detection techniques make PID an interesting area of research also for the computer science community. In this work, we show the current status of the ML approach to PID in ALICE. We discuss the preliminary work with the Random Forest approach for the LHC Run 2 and a more advanced solution based on Domain Adaptation Neural Networks, including a proposal for its future implementation within the ALICE computing software for the upcoming LHC Run 3.
Symmetry-induced many-body quantum interference in chaotic bosonic systems: an augmented truncated Wigner method
Authors: Hummel Q , Schlagheck P
Published: July 2022

Although highly successful, the truncated Wigner approximation (TWA) does not account for genuine many-body (MB) quantum interference between different solutions of the mean-field equations of a bosonic MB system. This renders the TWA essentially classical, where a large number of particles formally takes the role of the inverse of Planck’s constant ℏ. The failure to describe genuine interference phenomena, such as localization and scarring in Fock space, can be seen as a virtue of this quasiclassical method, which thereby allows one to identify genuine quantum effects when being compared with ‘exact’ quantum calculations that do not involve any a priori approximation. A rather prominent cause for such quantum effects that are not accounted for by the TWA is the constructive interference between the contributions of symmetry-related trajectories, which would occur in the presence of discrete symmetries provided the phase-space distribution of the initial state and the observable to be evaluated feature a strong localization about the corresponding symmetry subspaces. Here we show how one can conceive an augmented version of the TWA which can account for this particular effect. This augmented TWA effectively amounts to complementing conventional TWA calculations by separate truncated Wigner simulations that are restricted to symmetric subspaces and involve weight factors that account for the dynamical stability of sampling trajectories with respect to perpendicular deviations from those subspaces. We illustrate the validity of this method at pre- as well as post-Ehrenfest time scales in prototypical Bose–Hubbard systems displaying chaotic classical dynamics, where it also reveals the existence of additional MB interference effects.
Field theory for zero temperature soft anharmonic spin glasses in a field
Authors: Urbani Pierfrancesco
Published: July 2022

We introduce a finite dimensional anharmonic soft spin glass in a field and show how it allows the construction a field theory at zero temperature and the corresponding loop expansion. The mean field level of the model coincides with a recently introduced fully connected model, the KHGPS model, and it has a spin glass transition in a field at zero temperature driven by the appearance of pseudogapped non-linear excitations. We analyze the zero temperature limit of the theory and the behavior of the bare masses and couplings on approaching the mean field zero temperature critical point. Focusing on the so called replicon sector of the field theory, we show that the bare mass corresponding to fluctuations in this sector is strictly positive at the transition in a certain region of control parameter space. At the same time the two relevant cubic coupling constants g
1 and g
2 show a non-analytic behavior in their bare values: approaching the critical point at zero temperature, g
1 → ∞ while g
2 ∝ T with a prefactor diverging at the transition. Along the same lines we also develop the field theory to study the density of states of the model in finite dimension. We show that in the mean field limit the density of states converges to the one of the KHGPS model. However the construction allows a treatment of finite dimensional effects in perturbation theory.
Influence of road conditions on the values of longitudinal acceleration during braking of a tourist coach
Authors: Łagowski P , Stańczyk T , Szumska E , Zuska A , Grabski P , Jaśkiewicz M , Jurecki R , Kurczyński D
Published: July 2022

The paper aims to analyse the longitudinal acceleration of a tourist coach on various road pavements. As part of the experimental research, braking tests were carried out at a speed of 30 km/h and acceleration to a speed of 30 km/h. The tests were carried out on four types of pavement, i.e. dry and wet asphalt and dry and wet concrete. The article describes the impact of road conditions on the braking and acceleration performance on selected road pavement types. To increase the reliability of the test results, ten tests were carried out for each tested pavement. Based on the test results, graphs of braking decelerations and accelerations during accelerating the vehicle as a function of time. This allowed for statistical analysis of the recorded decelerations and accelerations.
IR spectroscopy analysis of skid marks for vehicle equipped with ABS considering slip ratio
Authors: Sys E , Gosławski Ł. , Mrowicki A , Głogowski M , Madziara S , Droś B , Zakrzewicz W , Kubiak P
Published: July 2022

Skid marks are an important source of information for road accident investigators. Up till now, analyzing them was a difficult task when ABS equipped vehicles are considered. Authors managed to solve this issue using IR spectroscopy. There are several factors to consider when investigating brake marks and one of them is slip ratio that was taken into account in this paper. Results show that for slip of 10% and more, IR spectroscopy technology was successful at revealing skid marks.
Airborne sound transmission in fluted PVC panels-properties of materials and structures
Authors: Kopania JM , Zakrzewicz W , Kubiak P , Mrowicki A , Głogowski M , Gralewski J , Bogusławski G , Wójciak K , Gaj P
Published: July 2022

Authors present a study on transmission loss and absorption of corrugated PVC panels. Tests were conducted in reverberation room and it has been proven, both theoretically and experimentally, that there is a relationship between the panel type and its transmission loss and absorption. Panel size and thickness was also taken into consideration during testing procedure. Analyses also show that the Hansen model was not perfectly accurate when predicting the transmission loss for some of the tested samples.
Study of lateral acceleration of a Ford Transit car on various road surfaces
Authors: Kurczyński D , Łagowski P , Stańczyk T , Szumska E , Zuska A , Grabski P , Jaśkiewicz M , Jurecki R
Published: July 2022

The measurement of car acceleration in time can be used to assess driving styles and safety behaviours of drivers. The values of lateral acceleration of the car can be an indication of the driver’s aggressive driving style and tendency for risky behaviour. If the lateral acceleration is too high, it may affect the car’s stability and potentially cause it to roll over. The paper outlines the results of the lateral acceleration analysis of a Ford Transit car driving in a circle and in the attempt to change two driving lanes. The tests were conducted in driving practice areas. Measurements were taken for the test vehicle driving in circles with maximum attainable velocity, and changing two driving lanes with pre-specified velocity. The tests were conducted on asphalt and concrete surfaces, in dry, wet and icy conditions. The purpose of the tests was to determine the maximum lateral acceleration of the analysed vehicle. The impact of the surface condition on the lateral acceleration of the test vehicle was also determined. The obtained results can be used as threshold values to assess driving style, and to analyse causes of accidents taking into consideration the condition of the road surface.
Road testing of lateral acceleration in urban bus
Authors: Szumska E M , Stańczyk T L , Zuska A , Grabski P , Jaśkiewicz M , Jurecki R , Kurczyński D , Łagowski P
Published: July 2022

Lateral acceleration is one of the parameters used to assess a driver’s behaviour and the comfort of urban bus passengers. Because of its purpose, a city bus is a vehicle designed to transport large numbers of people over relatively short distances. The specific driving conditions require constant stopping and accelerating. Lateral acceleration values collected in selected road manoeuvre tests or performance tests conducted in real traffic conditions will determine the lateral vehicle movement dynamics. This paper presents the results of lateral acceleration in a urban bus, obtained during experimental studies in selected road manoeuvres on various surfaces. The surface condition and type do not substantially affect the lateral acceleration when driving on a circular track. During test drives on a circular track, the range of lateral acceleration amounts to 5.56÷7.37 m/s2. The lateral acceleration obtained during double lane change attempts amounted to 2.84÷4.42 m/s2. The maximum lateral acceleration values achieved by the urban bus on a dry and wet asphalt surface are similar.
Experimental testing of longitudinal acceleration in urban buses
Authors: Szumska E M , Stańczyk T L , Zuska A , Grabski P , Jaśkiewicz M , Jurecki R , Kurczyński D , Łagowski P
Published: July 2022

A vehicle’s longitudinal acceleration is one the parameters that characterize a vehicle’s motion dynamics and used, among others, to assess the comfort of public bus passengers. Rapid acceleration and braking performed by urban bus drivers can be deemed by passengers as uncomfortable and dangerous in some situations, especially for standing passengers. This paper presents an analysis of a public bus’s longitudinal acceleration recorded during extreme acceleration and braking attempts. The experimental tests were conducted on dry and wet asphalt and concrete surfaces. The test results allow for the statement that lateral acceleration depends largely on the road’s surface and its type. The maximum longitudinal acceleration values during rapid acceleration, depending on the surface, are within the narrow range of 2.18-2.81 m/s2. During braking, a public bus’s minimum longitudinal acceleration was within the range of -5.58÷-8.54 m/s2.
Frontal collision simulation in laboratory conditions
Authors: Frej D , Jaśkiewicz M , Kubiak P , Zuska A , Więckowski D
Published: July 2022

The article presents the displacement of individual body parts of volunteers during a controlled crash test at low speed. The crash test stand used is equipped with a vehicle seat with standard seat belts, which moves along the ramp rails. The stand enables both front, side and rear crash tests. The stand enables crash tests from 5 km/h to 20 km/h. The aim of the research is to compare the displacements of individual parts of the volunteers’ body, taking into account the division into sex. A study carried out on 130 volunteers (80 men and 50 women), at a collision speed of 15 km/h, showed slight differences in the trajectory of the volunteers’ head movement. Before the study, the volunteers were measured and weighed, and then assigned to the appropriate population percentile. Volunteers were classified into a given percentile group on the basis of the mean of 15 anthropometric dimensions of individual body parts. The obtained results are the basis for building a physical model of a dummy.
Military special vehicle multifunctional seat as an element of vehicle passive safety
Authors: Wróbel T , Szudrowicz M , Luty W , Seńko J
Published: July 2022

Road safety depends on the interaction in the human - vehicle - road system. The proper functioning or condition of each of these three elements is a prerequisite for ensuring the maximum possible level of safety. The most important requirement that is placed on special vehicles is to ensure crew protection during the implementation of operational tasks. Unfortunately, often when putting operational tasks overriding during designing vehicles, aspects related to driving comfort are ignored. The article presents a proposal for the description of light construction of seats for the crews of special vehicles, which, apart from the functions related to the ergonomic use of seats by the crew, in terms of safety ensure a high probability of protection of health and life of the crews during a collision or near detonation of an explosive charge. Proposed modular structure of the seats, in addition to the repeatability of elements, which reduces production costs and easy configuration of seats with various functions, will also contribute to a faster process of restoring their functionality in the event of damage. Modules should be selected and developed in such a way that they can be used in various configurations of seats, the functions of which can be determined due to: location in the vehicle, i.e. driver’s, troops, system operators’ seats, installation method, i.e. to the wall, floor, ceiling, direction assembly, i.e. side mount, rear mount, bottom mount.
Comparison of driver awareness in real traffic and driving on a simulator
Authors: Beňuš J. , Poliak M.
Published: July 2022

A driver’s awareness is a critical aspect that must be closely monitored at all times. This article proposes a number of experiments that will be carried out in the near future, the findings of which may aid in improving the existing condition. The authors feel that the results of individual measurements can help to improve road freight transportation safety. Furthermore, the contribution focuses on driver drowsiness as a significant factor and mechanism of major and fatal traffic accidents, as well as extensive damage to goods or property in road freight transit. Among other things, detection of driver drowsiness was determined. The individual measurements are described and the result of a driver on the simulator are compared with a motorist driving in real traffic. With this information obtained from the individual measurements, we can evaluate number of driver mistakes and different signs of tired behaviour per one shift and then we could be able to estimate a maximum driving duration of one day for twenty-four hours day.
Knowledge centre for transport accessibility and mobility of people with special needs using individual transport modes
Authors: Jackowski J , Gidlewski M , Posuniak P
Published: July 2022

At the Military University of Technology in Faculty of Mechanical Engineering has been estabilished a Knowledge centre for transport accessibility and mobility of people with special needs (PwSN). The main aim of the Centre’s activities is to extend issues of universal design and to develop, promote and disseminate innovative product solutions and universal service standards leading to increased mobility and improved road safety for PwSN using personal transport. An additional aim is to support teaching staff in preparation for education and in the implementation of training activities in the field of universal design, counteracting the exclusion of PwSN. The activities of the Centre involve the Faculty of Mechanical Engineering, the Institute of Psychology at Cardinal Stefan Wyszyński University and the Motor Transport Institute. The article presents in detail the intentions and expected results of the activities carried out by the Centre. It is assumed that the Centre’s activities will make it possible to develop and disseminate original solutions of systems and devices facilitating and supporting the use of individual means of transport by PwSN.
Lateral acceleration of passenger vehicle in roundabouts in term of cargo securing
Authors: Kuba O. , Jagelcak J
Published: July 2022

In today’s modern infrastructure, roundabouts are found in almost every city, which makes them impossible to avoid. Roundabouts with a radius of up to 15 m generate high accelerations even when traveling at average speeds. For this reason, it is essential to analyze the events that occur when passing through such roundabouts. In the research, we have performed a complex analysis of the accelerations on the x, y and z-axis for five passes through five different roundabouts, with a focus on the vehicle dynamics. This helped us to understand how the vehicle behaves when crossing a roundabout, as well as what accelerations and forces are affecting the cargo. Therefore, the paper is comparing data from two sensors that were mounted on various parts of the vehicle. The first sensor was mounted on the dashboard and the second on the roof of the vehicle. What is more, we found that the Y-axis accelerations, which are the most important for the analysis of vehicle dynamics in roundabouts, are not affected by the change in sensor location. In addition, we performed an acceleration calculation based on the data recorded from the sensor and radius, which can serve as a basis for further research.
Design of an electro-pneumatic driving simulator
Authors: Woś Piotr , Dindorf Ryszard
Published: July 2022

The paper discusses the construction of a car driving simulator prototype. The basic design assumptions for the mechanical structure of the simulator platform as well as the drives and control system are presented. A solid model of the device was presented and a solution to its kinematics was proposed to determine the stroke of the driving cylinders as a function of the angular displacement of its members. The issues related to virtual prototyping to determine the trajectory of movement and dynamic quantities characterizing the simulator were presented. The construction of the control system with the use of a dedicated computer control card is discussed. Such a solution enables testing the functions of the simulator control system before its connection with the real simulator. At the same time, the design process has been significantly improved and accelerated.
Improvement of energy efficiency in the drive system of an electric car with PMSM
Authors: German Galkin S , Tarnapowicz D , Staude M , Zaleski T , Jaśkiewicz M
Published: July 2022

Thanks to the advantages, i.e. high overload, high power density factor, wide range of rotational speed, low moment of inertia, as well as high torque-to-inertia ratio, PMSM AC motors are currently widely used in electric cars. The article presents a new method of PMSM control through the modification of the Clarke and Park transforms that enables to improve the efficiency of the mechatronic system due to the energy criterion. The article shows analytical tests confirming the possibility of maintaining the reactive power at zero level in the inverter-PMSM circuit. The analytical tests were supported by simulation tests with the use of the MATLAB-SIMULINK program.
Carports as an element of energy security for electric vehicles
Authors: Małek A , Wojciechowski Ł
Published: July 2022

Energy security with regard to electric vehicles consists in providing an appropriate infrastructure in the form of charging points for electric vehicles, which are able to generate and supply the traction batteries of vehicles with an appropriate amount of electricity. This role is played very well by photovoltaic carports, which are the structures designed to generate electricity and generate a shadow. The vehicle parked under the carport structure is protected against excessive heating. The shade for the parked vehicle is provided by a photovoltaic system mounted on the roof of the carport. Carports are, therefore, an ideal solution for charging electric vehicles. The article analyzes the problem that is related to the selection of peak power of the carport for the electric vehicle (or vehicles) that will be parked under it. An economic and energy analysis is carried out to ensure the fastest and cheapest charging of an electric vehicle. The authors present a study of two cases of carports of different sizes, which were used to charge electric vehicles of various brands with different sizes of traction batteries and different powers of on-board chargers. The results obtained from the conducted research and analysis can be generalized to a larger number of carports and vehicles available on the market.
Focused electron beam transport through a long narrow metal tube at elevated pressures in the forevacuum range
Authors: BAKEEV Ilya , KARPOV Kirill , KLIMOV Aleksandr , OKS Efim , ZENIN Aleksey
Published: July 2022

We present here our investigations of the features of focused electron beam transport in free space at elevated pressures of a few pascals. We have explored the effect of the beam accelerating voltage, operating gas pressure, and magnetic focusing upon the trajectory of beam electrons in the crossover region, in particular on the beam convergence and divergence angles. It is shown that for the forevacuum pressure range of 2–5 Pa explored, a distinctive feature of the propagation of a focused electron beam with a current of up to 20 mA at an accelerating voltage of 10–20 kV is the difference in the angles of convergence (before the focus) and divergence (after the focus). Whereas at a low pressure of 2 Pa the divergence angle is smaller than the convergence angle, as the pressure increases the divergence angle increases and for pressures greater than 5 Pa the divergence angle is greater than the convergence angle. The results obtained were used in experiments on electron beam transport through a long narrow metal tube with a diameter of 5.8–9.2 mm and length of 10–30 cm. We show that for a 30 cm long tube of 7.5 mm diameter, the focused beam transmission can exceed 70%.
Wafer-scale microfabrication of flexible organic electrochemical transistors
Authors: Thiburce Quentin , Melosh Nicholas , Salleo Alberto
Published: July 2022

We describe a photolithographic process to fabricate organic microdevices on flexible substrates that relies on photolithography and dry etching and is entirely compatible with standard cleanroom wafer processing equipment. A conductive polymer is used as active material to fabricate organic electrochemical transistors on a flexible polyimide substrate. The transistors are operated both with a solid-state ion gel electrolyte and an aqueous electrolyte, thus demonstrating their applicability as building blocks as both flexible integrated circuits and biosensors. Miniaturized transistors with 2 μm-long channels are also demonstrated to showcase the ability of the microfabrication process to define small features. We believe the proposed process flow offers a high resolution alternative to printing techniques by taking full advantage of the superior reliability of established semiconductor device manufacturing techniques and facilities.
Conduction state transition induced by solitons in a graphene junction at room temperature
Authors: Righes Fabrizio , Vassallo Giorgio , Parchi Guido
Published: July 2022

The aim of this research was the study of the transition between high and low electrical resistivity states of two overlapped graphene layers when subjected to short electromagnetic pulses (soliton waves). These transitions have already been previously observed by the authors in experiments carried out with different conductors, separated by a tiny insulating layer. The choice of a highly ordered material, such as graphene, was justified by the attempt to achieve greater stability and reproducibility of these transitions. What has been observed is an instantaneous reversible transition of the graphene overlapped layers to/from a state of insulator with resistance in the order of Mohms from/to a state of resistance of few ohms or, in some cases, of zero ohms. The transition from a high resistance state to a lower one requires EM pulses of different polarity than the transition from a low resistivity state to a higher one. Some intermediate relatively stable states have also been observed.
VI—Aesthetic Beautification
Authors: Huddleston Andrew
Published: July 2022

Aesthetic beautification is a familiar artistic phenomenon. Even as they face death, heroes and heroines in operas still sing glorious music. Characters in Shakespearean tragedies still deliver beautifully eloquent speeches in the throes of despair. Even when depicting suffering and horror, paintings can still remain a transfixing delight for the eyes. In such cases, the work of art represents or expresses something to which we would, in ordinary life, attribute a negative valence (suffering, horror, death, and the like), but it does so beautifully. Doubtless there is not a single explanation for what transpires in art of this sort or in our experience of it. With some aesthetically beautified art, its foremost goal might be giving aesthetic pleasure, and the beauty of the aesthetic form, even when depicting horrors, is in the service of this primary aim. In other art, the beautification might seek to be jarring and thought-provoking, highlighting a disconnect between the aesthetic frame and what is portrayed. These routes explain much of aesthetic beautification. But I am particularly interested in considering another, still more specific, response: finding ourselves somehow consoled by the beautification. I begin with some reflections on aesthetic beautification in general, and then turn to consider how beautification and consolation might be connected, and what to make of this.