bluuebunny/crossref_metadata_2025 huggingface dataset:
CRISPR–Cas9 Gene Editing: Curing Genetic Diseases by Inherited Epigenetic Modifications
Authors: Kolanu Nikhil Deep
Published: March 2024

Introduction CRISPR–Cas9 gene editing, leveraging bacterial defense mechanisms, offers precise DNA modifications, holding promise in curing genetic diseases. This review critically assesses its potential, analyzing evidence on therapeutic applications, challenges, and future prospects. Examining diverse genetic disorders, it evaluates efficacy, safety, and limitations, emphasizing the need for a thorough understanding among medical professionals and researchers. Acknowledging its transformative impact, a systematic review is crucial for informed decision-making, responsible utilization, and guiding future research to unlock CRISPR–Cas9's full potential in realizing the cure for genetic diseases.

Methods A comprehensive literature search across PubMed, Scopus, and the Web of Science identified studies applying CRISPR–Cas9 gene editing for genetic diseases, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Inclusion criteria covered in vitro and in vivo models targeting various genetic diseases with reported outcomes on disease modification or potential cure. Quality assessment revealed a generally moderate to high risk of bias. Heterogeneity prevented quantitative meta-analysis, prompting a narrative synthesis of findings.

Discussion CRISPR–Cas9 enables precise gene editing, correcting disease-causing mutations and offering hope for previously incurable genetic conditions. Leveraging inherited epigenetic modifications, it not only fixes mutations but also restores normal gene function and controls gene expression. The transformative potential of CRISPR–Cas9 holds promise for personalized treatments, improving therapeutic outcomes, but ethical considerations and safety concerns must be rigorously addressed to ensure responsible and safe application, especially in germline editing with potential long-term implications.
A Study of Safety and Effectiveness of Evicel Fibrin Sealant as an Adjunctive Hemostat in Pediatric Surgery
Authors: Kenny Simon , Gabra Hany , Hall Nigel J. , Flageole Helene , Illie Bogdan , Barnett Ellie , Kocharian Richard , Sharif Khalid
Published: March 2024

Introduction Data on the use of fibrin sealants to control intraoperative bleeding in children are scarce. Evicel Fibrin Sealant (Ethicon Inc., Raritan, New Jersey, United States) was found safe and effective in clinical trials of adults undergoing various surgery types. We evaluated the safety and efficacy of Evicel versus Surgicel Absorbable Hemostat (Ethicon Inc.) as adjunctive topical hemostats for mild/moderate raw-surface bleeding in pediatric surgery.

Methods A phase III randomized clinical trial was designed as required by the European Medicines Agency's Evicel Pediatric Investigation Plan: 40 pediatric subjects undergoing abdominal, retroperitoneal, pelvic, or thoracic surgery were randomized to Evicel or Surgicel, to treat intraoperative mild-to-moderate bleeding. Descriptive analyses included time-to-hemostasis and rates of treatment success (4, 7, 10 minutes), intraoperative treatment failure, rebleeding, and thromboembolic events.

Results Forty of 130 screened subjects aged 0.9 to 17 years were randomized 1:1 to Evicel or Surgicel. Surgeries were predominantly open abdominal procedures. The median bleeding area was 4.0 cm2 for Evicel and 1.0 cm2 for Surgicel. The median time-to-hemostasis was 4.0 minutes for both groups. The 4-, 7-, and 10-minute treatment success rates were 80.0% versus 65.0%, 100.0% versus 80.0%, and 95.0% versus 90.0%, whereas treatment failure rates were 5.0% versus 25.0%, for Evicel and Surgicel, respectively. No deaths or thrombotic events occurred. Re-bleeding occurred in 5.0% of Evicel and 10.0% of Surgicel subjects.

Conclusions In accordance with adult clinical trials, this randomized study supports the safety and efficacy of Evicel for controlling mild-to-moderate surgical bleeding in a broad range of pediatric surgical procedures.
Statistical methods for linking material composition to recombination losses in optoelectronic devices
Authors: Giesl F. , Hartmann A. K. , Eraerds P. , Schubbert C. , Elanzeery H. , Heise S. , Dalibor T. , Parisi J.
Published: March 2024

In light of the accumulation of characterization measurement data in the industrial production of solar cell devices, the investigation of a large amount of samples by statistical means lends itself to be a useful tool to gain further insights into how the data correlate with performance parameters. However, due to the multicollinearity among high-dimensional input parameters of compositional data, revealing the underlying patterns may prove to be a difficult endeavor. In this work, we present statistics consisting of 280 thin-film solar cell samples based on Cu(In, Ga)(S, Se)2 absorber layers whose depth-resolved composition was assessed by glow-discharge optical emission spectroscopy (GDOES). After parameterization of the features of [Ga]/([Ga] + [In])and[S]/([S] + [Se]) gradings, we employ two-way clustering in order to group samples and features by their similarity. In addition, using principal component analysis, information in the dataset, which is irrelevant to the problem, is removed by dimensionality reduction. In this way, it is possible to create a map that provides an overview of the GDOES data of all samples in their entirety, including correlations among features. More importantly, it also opens up a more precise way to plan further improvements in the compositional gradings by unveiling a path along which the experimenter can read the feature changes concerned with an improvement in the open-circuit voltage deficit or any other target parameter of interest. New samples can then be assigned to existing cluster centroids to predict what target parameter value they would assume.
Numerical simulation of sound pressure characteristic in steam injection process
Authors: Li Jiqun , Zhang Dandi , Tong Lili
Published: March 2024

This numerical simulation study has been performed to investigate the dynamic characteristics, oscillation characteristics, and sound pressure of direct contact condensation at low steam mass flux. The volume of fluid model, Ffowcs Williams and Hawkings model, and condensation model are used to simulate the acoustic signal, which is produced during the steam injection process. The simulation results are verified by the experimental results to keep the applicability and accuracy of the model. The results show that the acoustic signal is related to the steam flow patterns. The vibration of the bubble volume, caused by the separation of bubbles, is the important factor for the generation of the acoustic signal. When the subcooled temperature is large, the chugging regime appears during the injection process. The sound pressure amplitude of the steam injection process increases significantly, with the increase in subcooled temperature. In the low-frequency region, which is below 10 Hz, the larger the subcooled temperature increases, the greater the sound pressure amplitude becomes.
Energy relaxation in a vacuum capacitor-resistor circuit: measurement of multiple decays with divergent time constants
Authors: Kowalski Frank V.
Published: March 2024

The decay of the electrical energy in a resistor-vacuum capacitor circuit is shown to involve multiple relaxation processes, with dramatically different time constants. This is measured using a vacuum capacitor to eliminate the effect of a dielectric between the plates (polypropylene capacitors are shown to exhibit similar behavior). A simple phenomenological model accounts for this behavior in spite of the difficulty in applying Maxwell's equations to such a circuit. These results will lead to a revision of our understanding of the physics of circuits, having particular impact on applications that use capacitors as sensors in collecting precision data (such as found in quantum measurements and dielectric spectroscopy).
Two-state model of energy dissipation at metal surfaces
Authors: Tully John C.
Published: March 2024

The rates and pathways of chemical reactions at metal surfaces can be strongly influenced by energy dissipation due to the nonadiabatic excitation of metallic conduction electrons. The introduction of frictional forces to account for this dissipation has been quite successful in situations for which the nonadiabatic coupling is weak. However, in cases where nonadiabatic coupling is strong, such as when electron transfer occurs, the friction model is likely to break down. Ryabinkin and Izmaylov have proposed 2-state and 3-state alternatives to the friction model for introducing electronic dissipation in molecular dynamics simulations. Here, we examine their 2-state model using some simple examples of atom–surface scattering. We find that, with the addition of decoherence, the 2-state model can produce quite promising results.
A red-emitting carborhodamine for monitoring and measuring membrane potential
Authors: Gest Anneliese M. M. , Lazzari-Dean Julia R. , Ortiz Gloria , Yaeger-Weiss Susanna K. , Boggess Steven C. , Miller Evan W.
Published: March 2024

Biological membrane potentials, or voltages, are a central facet of cellular life. Optical methods to visualize cellular membrane voltages with fluorescent indicators are an attractive complement to traditional electrode-based approaches, since imaging methods can be high throughput, less invasive, and provide more spatial resolution than electrodes. Recently developed fluorescent indicators for voltage largely report changes in membrane voltage by monitoring voltage-dependent fluctuations in fluorescence intensity. However, it would be useful to be able to not only monitor changes but also measure values of membrane potentials. This study discloses a fluorescent indicator which can address both. We describe the synthesis of a sulfonated tetramethyl carborhodamine fluorophore. When this carborhodamine is conjugated with an electron-rich, methoxy (-OMe) containing phenylenevinylene molecular wire, the resulting molecule, CRhOMe, is a voltage-sensitive fluorophore with red/far-red fluorescence. Using CRhOMe, changes in cellular membrane potential can be read out using fluorescence intensity or lifetime. In fluorescence intensity mode, CRhOMe tracks fast-spiking neuronal action potentials (APs) with greater signal-to-noise than state-of-the-art BeRST 1 (another voltage-sensitive fluorophore). CRhOMe can also measure values of membrane potential. The fluorescence lifetime of CRhOMe follows a single exponential decay, substantially improving the quantification of membrane potential values using fluorescence lifetime imaging microscopy (FLIM). The combination of red-shifted excitation and emission, mono-exponential decay, and high voltage sensitivity enable fast FLIM recording of APs in cardiomyocytes. The ability to both monitor and measure membrane potentials with red light using CRhOMe makes it an important approach for studying biological voltages.
Identifying outbreaks in sewer networks: An adaptive sampling scheme under network’s uncertainty
Authors: Baboun José , Beaudry Isabelle S. , Castro Luis M. , Gutierrez Felipe , Jara Alejandro , Rubio Benjamin , Verschae José
Published: March 2024

Motivated by the implementation of a SARS-Cov-2 sewer surveillance system in Chile during the COVID-19 pandemic, we propose a set of mathematical and algorithmic tools that aim to identify the location of an outbreak under uncertainty in the network structure. Given an upper bound on the number of samples we can take on any given day, our framework allows us to detect an unknown infected node by adaptively sampling different network nodes on different days. Crucially, despite the uncertainty of the network, the method allows univocal detection of the infected node, albeit at an extra cost in time. This framework relies on a specific and well-chosen strategy that defines new nodes to test sequentially, with a heuristic that balances the granularity of the information obtained from the samples. We extensively tested our model in real and synthetic networks, showing that the uncertainty of the underlying graph only incurs a limited increase in the number of iterations, indicating that the methodology is applicable in practice.
Optimal reaching subject to computational and physical constraints reveals structure of the sensorimotor control system
Authors: Greene Patrick , Bastian Amy J. , Schieber Marc H. , Sarma Sridevi V.
Published: March 2024

Optimal feedback control provides an abstract framework describing the architecture of the sensorimotor system without prescribing implementation details such as what coordinate system to use, how feedback is incorporated, or how to accommodate changing task complexity. We investigate how such details are determined by computational and physical constraints by creating a model of the upper limb sensorimotor system in which all connection weights between neurons, feedback, and muscles are unknown. By optimizing these parameters with respect to an objective function, we find that the model exhibits a preference for an intrinsic (joint angle) coordinate representation of inputs and feedback and learns to calculate a weighted feedforward and feedback error. We further show that complex reaches around obstacles can be achieved by augmenting our model with a path-planner based on via points. The path-planner revealed “avoidance” neurons that encode directions to reach around obstacles and “placement” neurons that make fine-tuned adjustments to via point placement. Our results demonstrate the surprising capability of computationally constrained systems and highlight interesting characteristics of the sensorimotor system.
Epistemic stance and public discourse on irregular migration in one of Europe’s outermost regions
Authors: Díaz-Peralta Marina
Published: March 2024

This article falls within the conceptual framework of critical discourse studies and cognitive linguistics whose
attention has focused on the discourse found in the public sphere on the topic of migration. I will demonstrate the results of my
analysis of a corpus composed of 74 opinion articles that were published in a Spanish regional newspaper between August 2020 and
February 2021. All of them focus on the same issue: the mass arrival of irregular migrants at one of Europe’s outermost borders,
the Canary Islands, and the social, political and economic strain that this is generating. The results of this analysis indicate
that the periphrastic auxiliary verb poder (can/could/might) constitutes an essential resource for the way in
which knowledge is managed by the authors whose intention is to fuel the debate by guiding the conceptualisation of reality of
readers who do not have perceptual access to the events described.
Revisiting the rhetorical construction of political consent
Authors: Ponton Douglas Mark , Ozyumenko Vladimir I. , Larina Tatiana V.
Published: March 2024

How political leaders construct consent is a constant theme of studies in political rhetoric and theories of
persuasion. We explore how populist linguistic strategies combine with traditional consensus-building to align populations with
the speakers’ messages. We observe similarities and differences in discourse strategies across two contrasting polities, the UK,
a foundational modern representative democracy and Russia, which is considered more autocratic. The data comes from speeches
given by Boris Johnson and Vladimir Putin during the Covid-19 crisis. They were analysed using Corpus Linguistics, compared in
qualitative analysis that identities key lexico-grammatical features. The findings show a convergence in some of the strategies
and linguistic styles, but also key differences which, we suggest, depend on cultural factors specific to the two nations. The
results contribute to our understanding of the operation of these resources in modern political discourse, highlighting the way
cultural factors influence rhetorical styles in very different political structures.
Analysis of the one-decoy-state SARG04 quantum cryptography protocol in the presence of afterpulse effects
Authors: Nian Hu , Nie Ya-Feng , Zhang Chun-Mei , Lu Liang-Liang
Published: March 2024

The SARG04 quantum key distribution protocol can offer greater robustness against photon number splitting attacks than the BB84 protocol that is implemented with weak pulses. In this paper, we propose a tight key analysis for the SARG04 protocol, by considering the one-decoy method and investigating its performance under the influence of a detector afterpulse. Our results demonstrate that an increase in block size leads to a slight increase in both the secure key rate and the maximum transmission distance. Importantly, the detector afterpulse plays a crucial role in practical applications and has a more pronounced effect on the SARG04 protocol compared to the BB84 protocol.
Six types of spin solitons in three-component Bose–Einstein condensates
Authors: Wang Yu-Hao , Meng Ling-Zheng , Zhao Li-Chen
Published: March 2024

Exact analytical solutions are good candidates for studying and explaining the dynamics of solitons in nonlinear systems. We further extend the region of existence of spin solitons in the nonlinearity coefficient space for the spin-1 Bose–Einstein condensate. Six types of spin soliton solutions can be obtained, and they exist in different regions. Stability analysis and numerical simulation results indicate that three types of spin solitons are stable against weak noise. The non-integrable properties of the model can induce shape oscillation and increase in speed after the collision between two spin solitons. These results further enrich the soliton family for non-integrable models and can provide theoretical references for experimental studies.
Inner-shell ionization cross sections of atoms by positron impact
Authors: Wang Yuan-Cheng , Ma Jia , Jiao Li-Guang , Fritzsche Stephan
Published: March 2024

The relativistic binary-encounter-Bethe model with Wannier-type threshold law is employed to obtain the inner-shell ionization cross sections of multi-electron atoms (Ni, Cu, Y, Ag, Au, Yb, Ta, and Pb) for positron impact energies from the thresholds up to 105 keV. There is good agreement between the present calculations and the experimental data. The constant in the acceleration term derived from the Wannier law is determined to be 0.2 and 0.5 for the K- and L-shells, respectively.
Research concerning the autonomy of the electric vehicles, simulated and measured, in the case of driving at the low and the medium speed, specific to the WLTC test.
Authors: Minzatu C , Nișulescu V , Toma M F , Rențea C , Bancă Gh
Published: March 2024

The most important attributes expected from today’s electric vehicles are the electricity consumption and the autonomy, which must be able to unequivocally replace the results achieved by the vehicles equipped with an internal combustion engine. These expectations come equally from the car manufacturers and from the end users. Based on these premises, in a first part of the paper, are presented the theoretical aspects concerning the test procedure for determining the autonomy of electric vehicles, applicable at the European level, with the highlighting of the low and medium driving zones, specific to the WLTC test. Also, are indicated theoretical details regarding the model of the electric vehicle tested and simulated, using the AMESIM modelling and simulation platform. In the second part are presented the comparative results obtained by measuring and simulating regarding the electric autonomy, respectively the influence that the driving at the low and the medium speed has, upon of the state of charge depletion of the traction battery.
Research concerning the autonomy of the electric vehicles, simulated and measured, in the case of driving at the high and the very high speed, specific to the WLTC test.
Authors: Minzatu C , Nișulescu V , Frățilă Gh , Stan C , Bancă Gh
Published: March 2024

In the current research, the autonomy and the energy consumption are the most important attributes expected from the electric road vehicles. Because the electric car manufacturing industry is in a continuous progress, this offers its customers a wide range of constructive variants through which their operational requirements can be met. It also has high expectations of the electric car manufacturers in the current energy context, to develop new high-performance models that can be considered as a real alternative to the current internal combustion engine solutions. So, the research part continues, and is a priority for all car manufacturers. Moreover, the computer simulation is also included as an intermediate stage before the final projects are validated. In the first part, there are detailed theoretical aspects of the electric vehicle to be tested and the test procedure applicable to it, specific to the WLTC cycle, for the high and very high-speed test area. Also, is described the vehicle model simulated using the AMESIM modelling platform. In the second part, are presented the experimental and simulated results performing a comparative analysis. Following the analysis, it has been possible to draw graphs showing the evolution of the state of charge and the mode of exhaustion of the autonomy, in the case of the two driving zones analyzed, respectively at high and very high speed.
Review of PEDELECS as an alternative to conventional means of urban transportation
Authors: Teodorașcu V , Burnete N V , Burnete N
Published: March 2024

Sustainable transportation solutions are more crucial than ever because of the pressing need to increase resource efficiency while lowering greenhouse gas emissions. The most recent advancements in the e-cycle sector have made a significant contribution to this goal and have attracted the interest of numerous businesses that offer mobility services. This paper discusses the main topics surrounding pedal electric cycles (PEDELECS) with an accent on a niche application, namely e-cargo cycles. The paper highlights not just the defining characteristics of these categories, but also other relevant aspects such as barriers to market penetration, general legislation, benefits for specific applications, as well as the significance of incentives, local infrastructure, and urban policies. Based on the available literature, it can be concluded that PEDELECS have a considerable potential to contribute to sustainability goals in urban areas due to their numerous benefits (functionality without emissions, less space occupied on roads, ability to access destinations with increased precision, ability to travel in car-restricted areas, lower costs compared to conventional vehicles, added health benefits to the users, versatility etc.). However, there are also significant challenges and barriers that must be overcome before they can see widespread adoption.
The design and development of an Integrated Propulsion System – Phase 2: the functional electric behaviour strategy
Authors: Croitorescu V , Duran B , Giurca L
Published: March 2024

The paper presents the integrated propulsion system implementation steps on a L6E road vehicle. The implementation followed several technical levels which are properly described within the paper. The functional behaviour in terms of electric propulsion was defined and developed. All the dedicated components were investigated, set and customized, to equip a L6E vehicle. Currently the electric machine, the battery pack, the user interface, the speedometer, the pedals, the power electronics etc. are implemented on a real existing L6E road vehicle, after they were defined and virtually tested.
Aspects of the combustion variability analysis at an automotive engine fuelled with hydrogen
Authors: Georgescu R , Pana C , Negurescu N , Cernat A , Nutu C , Sandu C
Published: March 2024

Over the last decades, the use of the alternative fuels was one of the main research activities for specialists in the field of internal combustion engines. The development of the modern automotive engines is constantly challenged by the more severe emission legislation. The engine emissions levels and the fuel efficiency are directly influenced by the engine operation, reproduction of the combustion phases from one cycle to other, cyclic dispersion during combustion process being important. In general, the use of alternative fuels in internal combustion engines provides an improvement of the energetic and pollution performance, or just a slight improvement of them, but the study of the combustion process must be completed with aspects regarding the cyclic variability. In particular, using this alternative fuel, a study of cyclic variation of the combustion process would be necessary in order to establish if the normal operation of the engine can be ensured. The paper presents some aspects of the analysis of the cyclic variability at a spark ignition engine fuelled with gasoline and hydrogen. During the engine operation at the regime of 2500 rev/min speed and 55% engine load, a number of 250 consecutive combustion cycles was recorded for classic fuel use and for hydrogen use. The coefficient of cyclic variation (CCV) or the coefficient of variation (COV) is determined for different combustion parameters such as maximum pressure, maximum pressure rise rate and mass fraction burned, defined by angles at which the conventional fractions of 10%, 50% and 90% of the heat of reaction is released. Thus, the values of the COV for maximum pressure (COV)pmax, maximum pressure rise rate (COV)dp/dα, angles of 10, 50 and 90% heat release as (COV)10%, (COV)50% and (COV)90% were calculated and compared with the admissible limit of 10%. The combustion variability analysis establishes the limits of the normal operation of the spark ignition engine fuelled with gasoline and hydrogen compared with the classic fuelling method.
Hydrogen fuelling a passenger car spark ignition engine for a cleaner environment
Authors: Nutu C , Pana C , Negurescu N , Cernat A , Georgescu R
Published: March 2024

The tightening of the restrictions on polluting emissions in the last decade and the possibility of the disappearance of the internal combustion engine in the field of transport must motivate the researchers in the field of internal combustion engines to find new solutions to fuel the spark ignition engine, aiming to reduce the negative impact of polluting emissions on the environment. Unconventional fuels represent a very good choice to fuel the spark ignition engines, based on their excellent combustion properties and hydrogen stands out among them. This paper presents experimental results of fuelling a car spark ignition engine with mixtures of gasoline and hydrogen. The experimental investigations have shown an improvement in the combustion process of the engine, a reduction in the energetic fuel consumption, an increase in the brake thermal efficiency and a decrease in the pollutant emissions level.
Surface Defects Vibration Measurements of Automotive Tapered Roller Bearings
Authors: Sabo B A , Voloacă Ş
Published: March 2024

The paper investigates vibration testing methodologies for automotive tapered roller bearings. The European Union regulations have indirectly led to improvements in the NVH performance of the bearings that affect both the industrial and automotive markets. The goal of this study was to examine the influence of localized small defects on the vibrations’ magnitudes within tapered roller bearings. A Rockwell indenter was used to create three different surface defects. These three levels, representing different indentation pressures, mimic defects that could occur during manufacturing or bearing installation. Indents were placed on inner raceways, the outer raceways, and the roller bodies. After the assembly of the components, different vibration testing methodologies were applied to quantify those types of defects. This paper presents a new envelope analysis approach to monitoring for defects. The paper presents the current Fast Fourier Transform (FFT) testing approach, whereby the machine sensitivity is representative of a typical quality control bearing thresholds. This paper also presents a new, more robust method and analyzed for its suitability in the detection of localized defects.
Analytical analysis of the thermal comfort of the occupants inside a truck cabin
Authors: Manea A M , Iozsa M D , Vieru E M
Published: March 2024

Thermal comfort inside a truck cabin is a parameter that influences the well-being of the driver and passengers. From the very first steps of designing the driver’s seat of a vehicle, the driver’s well-being is taken into account through ergonomic parameters. To analyze the ultimate comfort inside a truck cabin, a simplified sketch of the cabin will be proposed. The three-dimensional analytical calculation model is solved using the Ansys program in the Fluid Flow (CFX) module. Through modeling and numerical simulations, the temperature inside a truck cabin, the mode of movement of the air flow and the speed of the air flow are determined. Following these tests, it is checked whether the thermal comfort conditions for the driver and passengers in a truck cabin are respected and fulfilled. These term comfort conditions are evaluated based on some comfort indices available in specialized literature.
Finite element analysis and experimental study of strain for a vehicle rear suspension
Authors: Geonea I D
Published: March 2024

In this paper, aspects of the study of the durability of rear suspension components of a vehicle are discussed. These aspects are addressed in two ways, namely the study by CAD modelling and finite element method simulation, and secondly by experimental analysis on a durability test bench. In order to develop these research problems, an experimental stand is virtually modelled and studied by simulation using ADAMS software. Results are obtained that characterize the operation of the test bench system kinematically and dynamically. The studies are then completed by finite element analysis of the dependent rear axle and helical springs in the suspension structure. These results are corroborated with those obtained experimentally, i.e. stresses and strains recorded on the stand. The usefulness of these studies is that they allow the validation of different components of the rear suspension in terms of fatigue strength and different types of rear axles from cars can be tested, as the stand has a modular construction and the test parameters can be adjusted.
Aerodynamic means of reducing the influence of warning accessories on drag and emissions, for intervention vehicles
Authors: Ilea L , Stan C , Vieru M
Published: March 2024

Aerodynamic performance of passenger vehicles is one of the most efficient methods to further reduce the CO2 emissions and comply with the increasing constraints in the legislation. Previously performed studies on exterior warning accessories (systems with visual alerting signals that may be found on intervention vehicles e.g. ambulances), indicate a significant degradation of aerodynamic coefficient (Cd). Even if this category of vehicles does not have to comply with the standard emission rules, it is important to study and discover the means to reduce aerodynamic drag for this type of vehicles considering the general aim to reduce air pollution. The target would be to have a Cd level equal to that found in the base vehicles, before transformation (i.e. often, intervention vehicles are obtained by converting a vehicle available to general customers - multistage vehicle transformation).

The current paper’s purpose is to continue the investigation on methods to improve the aerodynamic performance of intervention vehicles. This will be done by compensating the shape and dimensions of the warning devices with the addition of supplementary body elements or by adapting existing parts. The Cd value of the different configurations is assessed using computational fluid dynamics (CFD) software based on Lattice Boltzmann mathematical model. 3D models of different generic body type vehicles (sedan, hatch back, SUV) were created and immersed in a virtual wind tunnel. To simulate the real-world measurement method specific boundary conditions on walls, inlets, outlets were set while the fluid environment was defined with a network from fine (2mm length, near the studied model), to coarse (20mm length, near exterior walls).

The results indicate that there is great potential in reducing the aerodynamic drag and, by extension, fuel consumption and CO2 emissions for all body types studied. Deviations could exist due to different make designs, or diversity of warning devices for example so the results obtained have a general nature. Nevertheless, the conclusion remains the same: if one’s aim is to improve air quality or prepare for new legislation (that will also apply to intervention vehicles), the aerodynamic optimization should be further scrutinized as it can prove to be a robust method to obtain the targeted results.
Comparison between gas flame welding and shielded gas welding in case of aluminium alloys
Authors: Babiş C , Dimitrescu A , Rugescu A M , Chivu O R , Enache CI
Published: March 2024

Although the assembly by welding of aluminum alloys is a common assembly process, it is done in quite difficult conditions, being forced to take into account a number of shortcomings, such as: high thermal conductivity which translates into losses of high heat in the welding area; formation of aluminum oxide films that melt at high temperatures, well above the melting temperature of the alloy; large expansion coefficients that result in the appearance of large deformations, the appearance of cracks in the joint at high temperatures due to loss of mechanical strength of the alloy, but also the appearance of pores, inclusions of aluminum oxide and corrosion in various aggressive environments. Despite all these shortcomings that occur in welding, aluminum alloys can be joined indestructibly by welding. The present paper aims, is to make a comparative study, based on experimental data, of two welding assembly processes, one with gas flame and another with shielded inert gas environments-WIG, for aluminum alloys of group 6000. The base material will be presented, the preparation of the basic material for welding through the two mentioned welding procedures and the steps taken to make the welded joints. The comparative study will include the parameters of welding regimes, non-destructive defectoscopy methods with which certain discontinuities can be identified and the destructive mechanical tests. The experimental results will be able to lead to pertinent conclusions on the possibilities of aluminum alloys welding assembly, using those two welding processes mentioned above, the results being easily generalized in the industrial fields.
Dynamic system for the study of bouncing vibrations of a car with active suspension model for an independent suspension
Authors: Popa D , Popa C M , Marcu S
Published: March 2024

At the beginning of the paper, the quantities that characterize a dynamic system are presented. Based on them, the state equations of the dynamic system are obtained, a system that models an active suspension. The types of used controllers, their block diagrams and the influence of the adjustment parameters on the process are reviewed. Next, numerical applications are made for the study of vibrations on models with 2 degrees of freedom, for an active suspension equipped with PID and LQR controllers. These controllers, as well as the simulation of the two systems, passive and active, were modelled and simulated using MATLAB/Simulink software. The numerical results obtained after the simulation are presented in the form of diagrams. In the end of the paper, it is concluded that the designed active suspension system can improve the ride quality by minimizing the displacement of the suspended mass.
Possibilities to evaluate the vehicle’s accelerations through MATLAB Simulink simulations
Authors: Duma I , Molea A , Cordoş N , Cărăuşan H , Burnete N , Barabás I , Todoruţ A , Jurchiş B M
Published: March 2024

This scientific present paper explores the methods for assessing the longitudinal and lateral accelerations of a vehicle through the combination of experimental validation and MATLAB Simulink simulations. Comprehending these accelerations is essential for a number of uses, such as stability, overall performance analysis, and vehicle safety. The first step of the study is building a detailed Simulink model of the car. With an emphasis on lateral and longitudinal accelerations, this model makes it easier to simulate a range of driving scenarios and explore how a vehicle handles and behaves under different circumstances. A key element of the study is the experimental validation of the Matlab Simulink model, which involves gathering real-world data from vehicle testing and contrasting it with simulated outcomes. Simulink model iterative refinement is made possible by the integration of simulation and experimentation, which ultimately improves the model’s predictive accuracy. The study’s conclusions demonstrate the integrated approach’s potential to advance vehicle dynamics analysis and make cars safer and more effective. Furthermore, it offers insights into the optimization of vehicle designs and the development of innovative control strategies to enhance overall road safety and vehicle performance.
Analysis of different dimensions of a virtual wind tunnel and different wall conditions
Authors: Vieru E M , Iozsa D M , Manea A M , Ilea L
Published: March 2024

Growing interest in improving the performance of vehicles is a subject that allows for continuous research. One such branch of these researchers is energy and consumption performance. These performances describe, on a global level, the need for lower fuel consumption but also a higher energy and power performance. Therefore, to create this balance, direct control of polluting emissions, especially C02 emissions, is necessary. Creating the best mix between low fuel consumption, maximum power of internal combustion engine and low pollutant emissions is influenced by many factors. One such factor, of prime importance, is represented by the aerodynamics of vehicle, in particular the aerodynamic performance, which needs to be tested to be confirmed, so numerical values are needed. Therefore, different ways of testing in the physical or virtual environment are necessary. To facilitate the optimization of a vehicle from an aerodynamic point of view, the most practical way is the virtual wind tunnel, given the possibility to test, at the same time, more configurations. But the CFD (Computational Fluid Dynamics) simulations, sometimes, have the disadvantage of very long compilation times. So, in the presented paper the construction of an optimal virtual wind tunnel for trucks will be presented, focusing on the test area (chamber) and several configurations will be presented such as: different proximity of the tunnel walls to the tested object so a different geometry of the test chamber and condition for the type of floor with different roughness than base case to simulate a more realistic road surface. Following the CFD simulations, it was observed the influence that increasing the dimensions of the test chamber has on the results obtained, so that moving the walls away from the test model generates much more realistic results. In addition, another thing that has an impact is the roughness of the floor, which, in this particular case, generate a 10% difference between the values obtained. Therefore, it will be possible to optimize the tunnel as best as possible to have results as close as possible to reality and in a reduced time.
The influences of human factors on road accidents in Romania in the period 2013 – 2022.
Authors: Dimitriu C I , Frătilă G
Published: March 2024

The main objective of the study is to establish a correlation between the main causes of road traffic accidents in Romania and “human factors”. The aim of the study is to show that accidents are attributed exclusively to human mistakes in a higher percentage than. The data used in the research are taken from the database of the Traffic Police-for Road traffic accidents during 2013-2022 and from the database of the Romanian Road Authority - ARR - for road safety inspections during 2018-2021. From the perspective of human factors, the research will give answers on the nature of the causes that lead to the production / favouring of road accidents in Romania and will propose solutions to address road risks to improve road infrastructure safety. As a case study, the research will focus on the human factors that contribute to road accidents on National Road 2. Compared to other national roads, on DN 2 road accidents occur with the highest number of fatalities, approximately 8.28% of all road deaths nationwide. The analysis of findings from road safety inspection reports carried out on DN2 shows that there is a correlation between road infrastructure non-conformities and causes of road traffic accidents.
Road infrastructure safety assessment using the integrated method - case study DN2.
Authors: Dimitriu C I , Frățilă G
Published: March 2024

This study aims to practically test, identify vulnerabilities and analyses the limits of working tools for assessing road network safety and validate the integrated method proposed by the European Commission in the context of different technical classes of national roads in Romania. The research aims to adapt, convert, and transform the calculation values of the formulas of the proactive evaluation tool to the values used by national norms for road design and construction. 2 evaluation parameters are analysed, which represent the width of the traffic lane, respectively the widths and type of shoulders. On the other hand, the study is a tool for analysing road infrastructure safety, for efficiently allocating resources and for prioritising specific road safety inspections on the most dangerous sections of roads. The case study is the comparison of the results obtained from the safety assessment of DN 2 road infrastructure, both by the proposed test method and by the method adopted by the European Commission following Member States’ comments.
Evaluation of different vehicle types by using modelling algorithms in road traffic virtual networks platforms
Authors: Gencărău N D , Matei L , Dumitru I , Stănciuc-Oţăt O V , Racilă M , Oprica A , Racila L
Published: March 2024

With the growing demand for simulating and analyzing road traffic, the scope of project planning, modelling, and execution will no longer be restricted to domain experts. In the future, a significantly larger portion of engineering and traffic management professionals will be required to carry out these activities. In this context, it is necessary to have several modelling and analytic algorithms that are based on the current state of affairs. Currently, the research in this subject is facing issues related to driving style variables and the integration of vehicles with the Intelligent Transportation System (ITS). Recently, there has been a focus on studying the significance of driving style for vehicle classes in connection to traffic flow, enhanced comfort, road safety, and the decrease of chemical and noise pollution. The configuration of traffic patterns is constantly changing, leading to the increasing prevalence of the idea of micro-mobility in recent years. The authors provide a comprehensive overview of the primary mathematical models employed in specific applications, as discussed before.
Particularities regarding the design and conception of a bodywork superstructure intended for the transportation of perishable goods
Authors: Beles H , Scurt F B , Tolea B A , Mitran T , Tent V I
Published: March 2024

The aim of this paper is to present the characteristics of the design and construction of a vehicle body superstructure intended for the transportation of perishable goods. In the first phase, the design of the superstructure was conceived, followed by its design. Then, the calculation of the mass distribution on the truck axles, as well as the calculation of the truck’s cornering, was carried out, and finally, the superstructure was made, which was mounted on the truck.
Wavenumber-explicit stability and convergence analysis of ℎ𝑝 finite element discretizations of Helmholtz problems in piecewise smooth media
Authors: Bernkopf M. , Chaumont-Frelet T. , Melenk J.
Published: March 2024

We present a wavenumber-explicit convergence analysis of the

h
p

hp

Finite Element Method applied to a class of heterogeneous Helmholtz problems with piecewise analytic coefficients at large wavenumber

k
k

. Our analysis covers the heterogeneous Helmholtz equation with Robin, exact Dirichlet-to-Neumann, and second order absorbing boundary conditions, as well as perfectly matched layers.
Universal convexity and range problems of shifted hypergeometric functions
Authors: Sugawa Toshiyuki , Wang Li-Mei , Wu Chengfa
Published: March 2024

In the present paper, we study the shifted hypergeometric function

f
(
z
)
=

z

2

F

1

(
a
,
b
;
c
;
z
)

f(z)=z_{2}F_{1}(a,b;c;z)

for real parameters with

0
>
a
≤
b
≤
c

0>a\le b\le c

and its variant

g
(
z
)
=

z

2

F

2

(
a
,
b
;
c
;

z
2

)

g(z)=z_{2}F_{2}(a,b;c;z^2)

. Our first purpose is to solve the range problems for

f
f

and

g
g

posed by Ponnusamy and Vuorinen [Rocky Mountain J. Math. 31 (2001), pp. 327–353]. Ruscheweyh, Salinas and Sugawa [Israel J. Math. 171 (2009), pp. 285–304] developed the theory of universal prestarlike functions on the slit domain

C

∖
[
1
,
+
∞
)

\mathbb {C}\setminus [1,+\infty )

and showed universal starlikeness of

f
f

under some assumptions on the parameters. However, there has been no systematic study of universal convexity of the shifted hypergeometric functions except for the case

b
=
1

b=1

. Our second purpose is to show universal convexity of

f
f

under certain conditions on the parameters.
A necessary and sufficient condition for double coset lumping of Markov chains on groups with an application to the random to top shuffle
Authors: Britnell John , Wildon Mark
Published: March 2024

Let

Q
Q

be a probability measure on a finite group

G
G

, and let 

H
H

be a subgroup of

G
G

. We show that a necessary and sufficient condition for the random walk driven by

Q
Q

on

G
G

to induce a Markov chain on the double coset space

H
∖
G

/

H

H\backslash G/H

is that

Q
(
g
H
)

Q(gH)

is constant as 

g
g

ranges over any double coset of

H
H

in

G
G

. We obtain this result as a corollary of a more general theorem on the double cosets

H
∖
G

/

K

H \backslash G / K

for 

K
K

an arbitrary subgroup of

G
G

. As an application we study a variation on the

r
r

-top to random shuffle which we show induces an irreducible, recurrent, reversible and ergodic Markov chain on the double cosets of

S
y
m

r

×

S
y
m

n
−
r

\mathrm {Sym}_r \times \mathrm {Sym}_{n-r}

in

S
y
m

n

\mathrm {Sym}_n

. The transition matrix of the induced walk has remarkable spectral properties: we find its invariant distribution and its eigenvalues and hence determine its rate of convergence.
𝑝-adic limit of the Eisenstein series on the exceptional group of type 𝐸_{7,3}
Authors: Katsurada Hidenori , Kim Henry
Published: March 2024

In this paper, we show that the

p
p

-adic limit of a family of Eisenstein series on the exceptional domain where the exceptional group of type

E

7
,
3

E_{7,3}

acts is an ordinary modular form for a congruence subgroup.