bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution of local curvature values as a sign for static signature verification
Authors: Akhundjanov Umidjon , Soliyev Bakhrom , Kayumov Ahror , Kholmatov Abrorjon , Musayev Khurshid , Ermatova Zarina
Published: April 2024

This paper proposes a new feature for describing a digital image of a handwritten signature based on the frequency distribution of local curvature values of the contours of this signature. The computation of this feature on a binary signature image is described in detail. A normalized histogram of the distributions of local curvature values for 40 intervals is generated. The frequency values, written as a 40-dimensional vector, are named the local curvature code of the signature. Experimental studies are performed on digitized images of genuine and fake signatures from two databases. The accuracy of automatic verification of signatures on the publicly available CEDAR database was 99.77% and on the TUIT database 88.62%.
Application of machine learning algorithms in determining the value perspectives of corporations
Authors: Malchenko Pavlo , Poltorak Anastasiia , Tyshchenko Svitlana , Ivanov Hennadii , Parkhomenko Oleksandr
Published: April 2024

The article solves an important problem of effective application of machine learning algorithms in the process of determining the perspectives of corporate value. The results obtained will allow reducing the losses incurred by companies as a result of value fluctuations by preparing in advance. The investigation employed the subsequent approaches: model modifications, automatic search of coefficients, construction of several models with different cut-off dates, support vector regression, etc. The conceptualization of the methodological approach to model modification based on the exclusion of suboptimal models and the comparison of model residuals and white noise is developed. The suggested approach comprises the subsequent phases: analysis and pre-processing of the data set; division of the prepared data into training and test samples; modeling and forecasting based on the modified model and the error limitation model; evaluation of the results. The architecture of an information system for forecasting based on time series models is developed. The efficiency of building multiple forecasts for solving machine learning problems is investigated. The substantiated recommendations will help to increase the accuracy of forecasting the perspectives of the value of corporations within a certain confidence interval.
Mathematical approximator based on basic spline approximation
Authors: Turdimatov Mamirjon , Mukhtarov Farrukh , Ibrokhimov Nodirbekh , Umarov Shukhratjon , Mirzayev Jamshid , Rakhmatov Rasuljon
Published: April 2024

The article considers the problem of constructing a mathematical piecewise linear approximator based on approximation by basis splines. An algorithm has been developed designed to implement a class of special functions and create parallel microprogramming for the algorithm for calculating spline functions and, on their basis, parallel operation of a microprogram automaton with associative memory.
Parallel steganographic algorithm based on least significant bit
Authors: Rafailov Radostin
Published: April 2024

The paper suggests a parallel algorithm for the implementation of the LSB steganographic method. The possibilities of parallel programming are presented. The proposed steganographic parallel algorithm is compared to an algorithm using sequential embedding of the hidden message (using one-core processor). It is established that the algorithm produces accurate statistical results.
Improving the thermal properties of lightweight concrete exterior walls
Authors: Goncharova Natalia , Ababakirova Zebuniso , Davlyatov Shokhrukh , Umarov Shodiljon , Mirzababayeva Sahiba
Published: April 2024

This article is devoted to the development of energy-efficient porous expanded clay concrete for exterior walls. Experimental data confirming the expediency of designing the optimal composition of porous concrete according to the general method of designing the optimal composition of the general theory of artificial building conglomerates (ABC) are presented. The presence of waste ash from thermal power engineering and a complex gas–forming agent based on the polymer K-9 reagent in the concrete provided increased durability, improved humidity and thermal engineering conditions of porous concrete.
Numerical analysis of single SC-50-800 and SC-50-500x2-x4 group centrifugal cyclones: efficiency comparison
Authors: Madaliev Murodil , Usmonov Mavlonbek , Kadyrov Khasanboy , Abdullajonov Nurzoda , Mavlonova Dilnoza , Otakhanova Zamira , Muminov Kamolkhan
Published: April 2024

Centrifugal cyclones are important devices used to separate solids or liquids from gas streams using centrifugal forces. They are widely used in various industrial processes and air and gas purification systems. In this work, numerical modeling and study of the efficiency of cyclones of various configurations are carried out: single cyclone SC-50-800, group cyclones SC-50-500x2 and SC-50-400x4. To conduct the study, the engineering software package Comsol Multiphysics 6.1 was used with the addition of the Flow Simulation module, specialized for modeling hydrodynamic processes. To simulate turbulent flows, thev2-fmodel was chosen, which is often used in the case of swirling flows. The computational experiment was carried out at a constant air flow rate of 4500 m3/h. Based on the obtained numerical data, an analysis of the effectiveness of various cyclone configurations was carried out. The results of the study show that the operating efficiency of group cyclones significantly exceeds the efficiency of single cyclones. This is confirmed by analysis of separation parameters and comparison of performance indicators of various cyclone configurations. The data obtained can be useful for the design and optimization of gas stream purification systems in various industrial and environmental applications.
Study of the SST turbulence model for the 2D NASA wall-mounted hump separated FLOW problem with plenum case
Authors: Madaliev Murodil , Abdulkhaev Zokhidjon , Kurpayanidi Konstantin , Abdullayev Alisher , Ilyosov Asrorjon
Published: April 2024

The article presents the results of the standard SST turbulence model in the Comsol Multiphysics 6.1 software package for 2D NASA wall-mounted hump separated flow with plenum case problems, which are presented in the NASA database. In this work, the finite element method is used for the numerical implementation of the turbulence equations. To stabilize the discretized equations, Galerkin least squares (GLS) stabilization and crosswind propagation stabilization were used. The results were taken for different computational grids. The results obtained are compared with the results of experimental data.
Soil contamination and changes in some properties of the soils scattered around the Almalyk mining and metallurgical combine
Authors: Jabbarov Z. , Abdrakhmanov T. , Sultonova N. , Abdullaev Sh. , Nomozov U. , Cabelkova I. , Smutka L.
Published: April 2024

In order to determine the level of contamination of the area, the formulas of Muller, Hokonson and Nemerow were used. Using the information of 2009 on this area, the changes by years were analyzed with the results obtained during the scientific research. The advantage of using pollution indicators is the possibility of direct comparison of different objects in the world; used conditional on geochemical background values. Thus, indicators provide direct information about the quality of the soil environment, and pollution indices are a tool for objective assessment. When comparing the results of 2009 and 2021 along the same route with a 12-year difference, the indices have changed, pollution at a distance of 2 and 8 km has changed to an average index. These indicators mean that during the years of the operation of the combine, the index of soil pollution will increase, and it will increase by one class every 10 years.
Specifications for applying high octane additives to the motor gasoline in hot climate
Authors: Alimova Zebo , Niyazova Gulxayo , Sabirova Dilorom
Published: April 2024

The article analyzes the use of high-octane additives to motor gasoline used in hot climates. We have studied anti-knock additives as additives to improve the octane number of gasoline. An additive based on alcohols, octane-Booster, was used as such additives. Laboratory studies were carried out on the physicochemical parameters of AI-80 and AI-92 gasoline with the addition of an anti-knock additive. The results of the studies show that when gasoline is used in hot climates, the addition of high-octane components based on alcohols increases the octane number, but at the same time the boiling point of the light fraction of gasoline decreases. With an increase in the percentage of additive, the boiling point of the light fractions reached 58°C. Taking into account all the experimental data obtained, we suggest adding a percentage of this additive of no more than 3%, which shows the optimal octane number and distillation temperature of 10% gasoline for hot climates. With a further increase in concentration to 5%, the octane number increases, but at the same time the distillation temperature of 10% gasoline sharply decreases, which can lead to increased friction losses. When the concentration increased above 5%, the octane number did not change. To ensure optimal engine operating conditions in hot climatic conditions, we suggest ensuring that the boiling point of gasoline at the beginning of distillation is not lower than 40°C ÷ 43°C, and the distillation temperature of 10% gasoline is not lower than 70°C.
On the convergence of discrete dynamic unbalanced transport models
Authors: Li Bowen , Zou Jun
Published: April 2024

A generalized unbalanced optimal transport distance WBΛ on matrix-valued measures M(Ω, 𝕊n+) was defined in Li and Zou (arXiv:2011.05845) à la Benamou–Brenier, which extends the Kantorovich–Bures and the Wasserstein–Fisher–Rao distances. In this work, we investigate the convergence properties of the discrete transport problems associated with WBΛ. We first present a convergence framework for abstract discretization. Then, we propose a specific discretization scheme that aligns with this framework, whose convergence relies on the assumption that the initial and final distributions are absolutely continuous with respect to the Lebesgue measure. Further, in the case of the Wasserstein–Fisher–Rao distance, thanks to the static formulation, we show that such an assumption can be removed.
Diagnose und Triage
Authors: Rubini Gimenez Maria , Thiele Holger
Published: April 2024

Der Begriff akutes Koronarsyndrom (ACS) umfasst ein weites Spektrum. Patienten mit der Arbeitsdiagnose ACS können final an einem akuten Myokardinfarkt (AMI) leiden – wobei wir zwischen Nicht-ST-Strecken-Hebungsinfarkt (NSTEMI) und ST-Strecken-Hebungsinfarkt (STEMI) unterscheiden – oder auch eine instabile Angina aufweisen. Die Anamnese, klinische Untersuchung, Veränderungen im 12-Kanal-EKG und die Bestimmung der Konzentration von kardialem hochsensitivem Troponin (hs-cTn) helfen dabei, ausgehend von der Arbeitshypothese akutes Koronarsyndrom eine definitive Diagnose stellen zu können.

Die Bandbreite der klinischen Präsentation von Patienten mit ACS ist groß und reicht von symptomfreien Patienten über Patienten mit anhaltenden Brustschmerzen bis zu Patienten mit Herzstillstand, elektrischer/hämodynamischer Instabilität oder kardiogenem Schock (CS). Zum initialen Management werden die Patienten mit ACS typischerweise anhand der EKG-Veränderungen klassifiziert. Im Weiteren kann eine Unterteilung basierend auf etwaigen laborchemischen Erhöhung von hs-cTn getroffen werden. Die diagnostischen Tools (Veränderungen des EKGs und hs-cTn) sind für die initiale Triage sowie Diagnosestellung essenziell, um eine Risikostratifizierung für den individuellen Patienten durchzuführen und die initiale therapeutische Strategie festzulegen.

Nach dem akuten Management und der Stabilisierung des Patienten ist die weiterführende therapeutische Strategie einheitlicher für alle ACS-Patienten und weist keine so diversifizierten Therapieschemata wie das initiale Management auf.
Anders heißt nicht krank – Neurodiversität
Authors: Zimpel André Frank
Published: April 2024

Nach dem Konzept der Neurodiversität weisen Menschen mit ADHS oder Autismus keine Störung oder Behinderung auf, sondern spiegeln lediglich eine andere Art der Funktionsfähigkeit des Gehirns wider. Prof. Dr. André Zimpel ist in der Neurodiversitätsforschung tätig und gibt Tipps zum Umgang mit neurodiversen Menschen in der Ergotherapie.
Let‘s talk about – Sexuelle Belästigung im Praktikum
Authors: Kranz Florence
Published: April 2024

Die Themen Sexismus und sexuelle Belästigung sind in öffentlichen Debatten angekommen. In der ergotherapeutischen Literatur finden sie jedoch bislang kaum Erwähnung. Das wollte Anne Witzel mit ihrer Masterarbeit ändern. Daher hat sie sechs (angehende) Ergotherapeut*innen dazu interviewt, welche Erfahrungen sie in ihrer praktischen Ausbildung mit sexueller Belästigung gemacht haben.
Pathomechanismen von Diabetes und Krebs
Authors: Klühs Christine
Published: April 2024

Diabetes und Krebs betreffen mit steigender Prävalenz einen Großteil der Bevölkerung in den Industrie- und Schwellenländern. Überernährung sowie verminderte körperliche Aktivität mit konsekutivem Übergewicht sind mit einem deutlich erhöhten Risiko für Diabetes und Krebs verbunden. In diesem Artikel werden gemeinsame Pathomechanismen von Krebs und Diabetes erläutert und auf präventive Maßnahmen und Empfehlungen eingegangen.
Verordnung von Antidiabetika und glykämische Kontrolle bei Erwachsenen mit Diabetes mellitus Typ 2 im zeitlichen Verlauf
Authors: Gölz Stefan , Eckert Alexander , Wosch Frank Jürgen , Hugenberg Inge , Karl Manuela , Seufert Jochen , Nun-Boetzel Heike , Wagner Siegfried , Weber-Lauffer Rosemarie , Milek Karsten , Naudorf Michael , Holl Reinhard Walter
Published: April 2024

In der vorliegenden Auswertung aus dem DPV-Register wird der Einsatz von unterschiedlichen Antidiabetika zwischen den Jahren 2005 bis 2021 ausgewertet und analysiert. Es konnten Daten von insgesamt 405 790 Menschen mit Diabetes ausgewertet werden (2 464 078 Beobachtungsjahre). Die Population (53,4 % männlich) war im Median 70,91 Jahre alt bei einer medianen Diabetesdauer von ca. 9 Jahren. Im Laufe des Auswertungszeitraumes nahm der Anteil der über 80-Jährigen kontinuierlich zu.

Seitens der Therapie nahm der Anteil der lediglich mit Insulin behandelten Patienten ebenso ab wie der Anteil der lediglich mit Lebensstil behandelten Patienten. Metformin wurde tendenziell zunehmend häufiger eingesetzt. Für Sulfonlyharnstoffe zeigte sich eine komplette gegensätzliche Entwicklung gegenüber den DPP-IV-Inhibitoren mit einer Zunahme dieser seit 2007 etablierten Substanzgruppe. Seit ungefähr 2015 zeigen sich deutlich zunehmende Verordnungshäufigkeiten für SGLT-2-Inhibitoren sowie GLP-1-Rezeptoragonisten bei gleichzeitig zu erkennendem allmählichem Rückgang der DPP-IV-Inhibitorverordnungen.

Während der Anteil der Metformin-Verordnungen im Beobachtungszeitraum in allen Altersgruppen kontinuierlich und weitgehend parallel anstieg, sind für SGLT-2-Inhibitoren und GLP-1-Rezeptoragonisten anfänglich bei der Gruppe der unter 60-jährigen und erst zeitversetzt auch der älteren Patienten eingesetzt worden. Seitens der Geschlechterunterschiede in den Verordnungen gibt es für GLP-1-Rezeptoragonisten quasi keine Unterschiede, bei Metformin gibt es ein ganz leichtes Überwiegen der männlichen Patienten, welches bei SGLT-2-Inhibitoren deutlicher wird.

Die mittlere glykämische Kontrolle ausgedrückt durch den HbA1c-Wert liegt in der gesamten Kohorte im Median bei 7,11 % (54,2 mmol/Mol) mit einem weitgehend unveränderten Verlauf über den Beobachtungszeitraum und einer klaren Differenzierung dahingehend, dass jüngere Patienten den höchsten medianen HbA1c aufweisen und die älteste Kohorte den niedrigsten.

Die Daten werden im Kontext sich ändernder Leitlinien und Empfehlungen diskutiert und analysiert.
Digitale Gesundheitsanwendungen – Unterstützung bei Diabetes
Authors: Bretschneider Maxi Pia , Schwarz Peter E.H.
Published: April 2024

Bereits 4 digitale Gesundheitsanwendungen (DiGAs) sind im DiGA-Verzeichnis des BfArMs gelistet, welche Patientinnen und Patienten mit Diabetes mellitus Typ 2 unterstützen: Vitadio (vorläufige Zulassung 04/21), mebix (vorläufige Zulassung 07/23), glucura Diabetestherapie (vorläufige Zulassung 01/24) und Una Health für Diabetes (vorläufige Zulassung 02/24) 1, 2, 3, 4. In diesem Artikel der DiGA-Serie wird die DiGA mebix unter die Lupe genommen, die wichtigsten Informationen präsentiert, sowie kleine Einblicke in die App gewährt.
Impact of 68Ga-PSMA PET/CT on radiation treatment planning of prostate cancer patients
Authors: Bock Felix , Frerker Bernd , Schubert Laura , Rennau Hannes , Kurth Jens , Krause Bernd J. , Hildebrandt Guido , Schwarzenböck Sarah Marie
Published: April 2024

Aim This study aimed to assess the impact of 68Ga-PSMA PET/CT on radiation treatment (RT) planning in prostate cancer patients with salvage (sRT) or definitive (dRT) radiotherapy.

Methods 38 patients (27 sRT, median PSA 0.79 ng/ml (range 0.06–12.1); 11 dRT, median PSA 4.35 ng/ml (range 1.55–55.5) underwent 68Ga-PSMA PET/CT before RT. Influence of 68Ga-PSMA PET/CT on the extent of planning target volume (PTV) and addition of PET-based boosts were assessed. Median follow up was 12 months (range 3–24).

Results
68Ga-PSMA PET/CT showed positive findings in 23/38 patients (8/23: local recurrence (LR), 11/23: nodal metastasis, 1/23: LR and nodal, 2/23: solitary bone metastasis, 1/23: oligometastatic nodal/ bone metastases). In sRT primary PTV was changed in 16/27 patients extending the PTV to the lymphatic drainage (10/16), PSMA-positive LR (3/16), bone metastases (2/16) and both nodal/bone metastases (1/16). PET-based increase of primary PTV was 116%. PET-based boosts were administered in 19/27 patients (8/19: local, 10/19: nodal, 1/19: both), median boost volume was 31.3 cm3 (range 17.2–80.2) (local) and 19.7 cm3 (range 3.0–109.3) (nodal). PTV was changed in 1/11 (9%) of dRT patients (extension of primary PTV to the lymphatic drainage (RT volume of 644.5 cm3), additional nodal boost (volume of 2.7 cm3, 23.1 Gy)). All patients showed biochemical response (mean PSA decrease 88.8 +/– 14.0%). Nadir PSA was reached 10 months (range 1–17) after end of RT (median 0.07 ng/ml, range 0.002–3.96). Within a median 12 months follow-up (range 3–22/8–24 in sRT/dRT), median PSA was 0.05 ng/ml (range 0.002–8.5) (sRT) and 0.26 ng/ml (range 0.02–2.68) (dRT).

Conclusions
68Ga-PSMA PET/CT influenced sRT planning in almost 63% and dRT in 9% of patients by change of PTV and additional boosts.
Spontaneous Clival Leaks and Their Management
Authors: Sara Katti Blessi , Upreti Garima , Thomas Habie , Philip Ajay , Sundaresan Rajan , Gandham Edmond Jonathan , Thomas Regi
Published: April 2024

Introduction Cerebrospinal fluid (CSF) leaks through the nasal cavity occurrence has a rising trend, of which primary spontaneous leak is 6 to 40% of all the CSF leaks. The most common site of CSF leak is ethmoid roof where the bone is thinner in the entire skull base. Clivus being the hard bone is a rare site for spontaneous leak. We present a case series from a single quaternary care center of this rare occurrence and study its reason and management strategy.

Materials and Methods A retrospective surgical audit over a period of 10 years of all patients diagnosed with CSF rhinorrhea was done. A PubMed search was conducted with keywords of CSF leak, CSF rhinorrhea, spontaneous CSF rhinorrhea, clival leak, and clivus to identify the literature and these articles were compiled and their management reviewed.

Results and Analysis A total of 100 patients underwent surgical management for spontaneous CSF leak, of which there were 5 patients who had spontaneous CSF rhinorrhea from the clivus. There were four female patients; four patients had high body mass index. The most common site of leak was mid-clivus and surgical technique employed was multilayer dural plasty with a nasoseptal flap and measures were taken to reduce the intracranial pressure intra-operatively and postoperatively.

Conclusion Spontaneous clival leak is a rare entity with mid and lower clivus being the common site. A combined approach by ENT and neurosurgeons results in best outcome for the patients.
Proteus Syndrome: Case Report and Updated Literature Review
Authors: Klimeczek-Chrapusta Maria K , Kachnic Marek , Chrapusta Anna
Published: April 2024

Proteus syndrome (PS) is an exceptionally uncommon genetic disorder that has been documented in only approximately 250 cases in the literature spanning the past four decades. It is characterized by a disproportionate, asymmetric overgrowth of all types of tissues, provoked by a somatic activating mutation in serine/threonine protein kinase 1. We report a case of PS in a two-year-old female patient with the following clinical features: unilateral overgrowth of connective tissue in the right buttock and right foot, where multiple surgeries were performed to achieve a desirable aesthetic outcome and ensure psychological comfort of the young patient. The insights provided by this case underscore the pivotal role of obtaining pleasing aesthetic outcomes in the surgical management of untreatable genetic disorders, with the aim of nurturing psychological contentment in affected children.
Methemoglobinemia as a Cause of Unexplained Hypoxia in Neurosurgical Patients: A Report of Two Cases
Authors: Bansal Sonia , Srinivasaiah Bharath , Sriram Vidya , Baradwad Vishal , Giribabu Parthiban , Mishra Rajeeb K.
Published: April 2024

In methemoglobinemia, ferrous iron in the hemoglobin is oxidized to a ferric state. Hemoglobin in this state cannot carry oxygen resulting in hypoxemia, which manifests as low peripheral oxygen saturation (SpO2). Bedside co-oximetry can identify this condition. We present here two cases of methemoglobinemia. Our experience with the first case enabled swift diagnosis of the second case. This also enabled us to prepare ourselves better in the second case if worsening of hypoxemia had occurred. Therefore, we learn here that whenever there is low SpO2 with a normal partial pressure of oxygen, methemoglobinemia should be suspected and diagnosis should be confirmed using co-oximetry.
Status Epilepticus: An Update on Pharmacological Management
Authors: Almohaish Sulaiman , Tesoro Eljim P. , Brophy Gretchen M.
Published: April 2024

Status epilepticus (SE) is a neurological emergency that requires timely pharmacological therapy to cease seizure activity. The treatment approach varies based on the time and the treatment stage of SE. Benzodiazepines are considered the first-line therapy during the emergent treatment phase of SE. Antiseizure medicines such as phenytoin, valproic acid, and levetiracetam are recommended during the urgent treatment phase. These drugs appear to have a similar safety and efficacy profile, and individualized therapy should be chosen based on patient characteristics. Midazolam, propofol, pentobarbital, and ketamine are continuous intravenous infusions of anesthetic medications utilized in the refractory SE (RSE) period. The most efficacious pharmacotherapeutic treatments for RSE and superrefractory status epilepticus are not clearly defined.
A setup for hard x-ray time-resolved resonant inelastic x-ray scattering at SwissFEL
Authors: Chen Hui-Yuan , Versteeg Rolf B. , Mankowsky Roman , Puppin Michele , Leroy Ludmila , Sander Mathias , Deng Yunpei , Oggenfuss Roland Alexander , Zamofing Thierry , Böhler Pirmin , Pradervand Claude , Mozzanica Aldo , Vetter Seraphin , Smolentsev Grigory , Kerkhoff Linda , Lemke Henrik T. , Chergui Majed , Mancini Giulia F.
Published: April 2024

We present a new setup for resonant inelastic hard x-ray scattering at the Bernina beamline of SwissFEL with energy, momentum, and temporal resolution. The compact R = 0.5 m Johann-type spectrometer can be equipped with up to three crystal analyzers and allows efficient collection of RIXS spectra. Optical pumping for time-resolved studies can be realized with a broad span of optical wavelengths. We demonstrate the performance of the setup at an overall ∼180 meV resolution in a study of ground-state and photoexcited (at 400 nm) honeycomb 5d iridate α-Li2IrO3. Steady-state RIXS spectra at the iridium L3-edge (11.214 keV) have been collected and are in very good agreement with data collected at synchrotrons. The time-resolved RIXS transients exhibit changes in the energy loss region <2 eV, whose features mostly result from the hopping nature of 5d electrons in the honeycomb lattice. These changes are ascribed to modulations of the Ir-to-Ir inter-site transition scattering efficiency, which we associate to a transient screening of the on-site Coulomb interaction.
Effect of impact and flexural loading on hybrid composite made of kevlar and natural fibers
Authors: Thakare P. A. , Kumar Neeraj , Ugale V. B. , Giri Jayant , Sunheriya Neeraj , Al-Lohedan Hamad A.
Published: April 2024

In this work, four varieties of hybrid Fiber-Reinforced Polymer (FRP) panels made of kevlar-29 and natural fibers are studied. All panels have kevlar-29 face sheets and natural fiber core, such as jute, flax, sisal, and hemp. This research focuses on the behavior of these hybrid FRP panels under flexural and impact loading so that the panels can be explored for the structural/semi-structural members of army shelters, portable helipad, and roofing panels in high-altitude areas. Natural fibers are chemically treated with NaOH to improve hydrophobicity. The panels are vacuum bagged, the fiber volume fraction is 0.39, and the thickness is close to 4 mm. Three-point flexural loading using the universal testing machine and low-velocity impact loading up to 24 J under drop weight impact test setup is carried out to characterize the panels. Damage area, delamination, permanent deformation, indentation depth, energy absorbed, flexural strength, and modulus are measured. The hybrid flax/kevlar panel and hemp/kevlar panel, each resist impact with permanent deformation less than 0.5 mm up to 24 J. Without significant face sheet or core fiber breakage, the delamination is spread over a small radial distance of 18.5 and 24.5 mm, respectively. Interface matrix breakage causes delamination. The load vs deflection curve is almost linear under flexural loading, and specimens failed under compression at 240 MPa. The numerical simulation is also done using ANSYS and LS-DYNA for detailed study.
Arc-extinguishing simulation and experiment on gas blast arc-extinguishing lightning protection gap
Authors: Guo Wei , Lin Nan , Wu Liang , Huang Ping , Qin Honglin
Published: April 2024

The gas blast arc-extinguishing lightning protection gap is a new type of lightning protection device based on airflow active arc-extinguishing. This paper establishes an airflow and arc mathematical model for calculating and analyzing air flow and arc motion processes. Besides, the finite element software ANSYS 14.0 is employed for the arc-extinguishing simulation in the pressure field, interaction arc, and airflow processes. Accordingly, the test analysis effects of the arc-extinguishing gap lightning protection test are verified. High-speed cameras, recording oscillograph arc-extinguishing images, and arc waveforms are employed in the process to obtain the airflow response time and arc-extinguishing time effectively based on the data analysis. Comparing the actual results with the simulation results demonstrates the arc-extinguishing reliability and provides an effective scientific basis for its practical application.
Enhancing low-orbit vibration energy harvesting by a tri-stable piezoelectric energy harvester with an innovative dynamic amplifier
Authors: Man Dawei , Jiang Bangdong , Xu Qinghu , Tang Liping , Zhang Yu , Xu Gaozheng , Han Tingting
Published: April 2024

Piezoelectric energy harvesting faces a primary challenge in effectively capturing low-orbit vibration energy across a broad frequency range. In this paper, we present a tri-stable piezoelectric energy harvester that incorporates a dynamic amplifier (TPEH + DM), specifically designed for efficient collection of low-orbit vibration energy. The TPEH + DM comprises a piezoelectric cantilever beam connected to an innovative dynamic amplifier at its restrained end, which enhances both the rotational and lateral displacement of the piezoelectric cantilever beam simultaneously. The governing coupled differential equations of motion for the system is derived based on the Lagrange equation, and analytical expressions for its steady-state response are obtained using the multi-scale method. The influence of factors such as the mass and the stiffness ratio of the dynamic amplifier on the steady-state dynamic output characteristics of the system is investigated using the theoretical analysis and numerical simulation. The results indicate that TPEH + DM exhibits significantly improved energy harvesting performance compared to TPEH under low-orbit external excitations. The bandwidth of inter-well motion and the TPEH + DM power output may be further increased by suitably modifying the relative stiffness between the cantilever beam and the dynamic amplifier. In addition, we analyze the time-domain behavior of the system’s output voltage using the ode45 solver under various external excitation frequencies and intensities. The results demonstrate that with appropriate adjustments to the mass of the tip magnet and the stiffness ratio of the dynamic amplifier, the proposed TPEH + DM system can harvest energy efficiently across a broad frequency range, even under low-orbit excitations.
A semi-analytical solution of the magnetohydrodynamic blood-based ternary hybrid nanofluid flow over a convectively heated bidirectional stretching surface under velocity slip conditions
Authors: Lone Showkat Ahmad , Khan Arshad , Raiza Zehba , Alrabaiah Hussam , Shahab Sana , Saeed Anwar , Bonyah Ebenezer
Published: April 2024

This work inspects the thermal transportation of the magnetohydrodynamic Casson trihybrid nanofluid flow over a convectively heated bidirectional elongating sheet. The flow is considered as three dimensional passing over the sheet, which is placed in a porous medium. The effects of thermal radiations and space- and thermal-dependent heat sources are used in energy equations, while magnetic effects are used in momentum equations. Appropriate variables have been used to convert the modeled equations into a dimensionless form, which have then been solved using the homotopy analysis method. In this work, it is uncovered that both the primary and secondary velocities are weakened with an upsurge in porosity and magnetic factors. The thermal transportation is augmented with growth in thermal- and space-dependent heat source factors and the thermal Biot number. The convergence of the method used in this work is ensured through ℏ-curves. The results of this investigation have also been compared with the existing literature with a fine agreement among all the results that ensured the validation of the model and method used in this work.
Particle simulation of the confinement of the plasma blanket in the magnetic mirror
Authors: Xiao Shiqi , Wu Tiannan , Wang Shaojie
Published: April 2024

A new guiding center particle code Guiding center Mirror Simulation is developed to simulate the evolution and confinement of the axisymmetric plasma blanket in the magnetic mirror field generated by a pair of Helmholtz coils. The simulation results indicate that this plasma blanket maintains its shape throughout evolution, and the steady state distributions of both density and electrostatic potential are obtained. The correlation between the plasma density and the characteristic confinement time is also investigated. Generally, the characteristic confinement time decreases with increasing density. When the density is low enough, it is approximately the pitch angle scattering time of the trapped electrons. When the density increases, it comes to several times of the ion transit time evaluated with the Bohm velocity. These results have the potential for experimental applications.
A comparative study on milling-induced surface roughness during milling of jute–epoxy and carbon–epoxy composites and optimization for better surface finish through Taguchi and RSM techniques
Authors: B. R. N. Murthy , Hiremath Anupama , Giri Jayant , Makki Emad , T. Sathish , Bolar Gururaj , H. M. Vishwanatha
Published: April 2024

During the present experimentation, milling machining was performed on two different composites, namely carbon fiber-reinforced polymer composite and jute fiber-reinforced polymer composite, using a computer numerical control vertical machining center. The selected machining parameters were spindle speed (S), feed rate (FR), depth of cut (DOC), and flute number or cutting edge number (FN). The output parameter is the machined surface roughness (Ra). Analysis of variance was used to predict the percentage influence of each parameter on machining quality. The parameter feed rate exhibited a higher influence on the machined surface roughness, followed by spindle speed, flute number, and depth of cut in sequence. Similarly, while milling the carbon fiber composite, the feed rate had the highest influence, followed by the parameter flute number. As for the surface roughness, the feed rate had a greater effect, followed by the spindle speed. Under the same machining conditions, it was observed that the sequence of parameters influencing the jute composite and carbon composite changed in the case of cutting force generation, but the sequence of parameters was the same for both cases in terms of roughness. The outcome of the work confirmed that to achieve a smaller value of roughness in the milling of jute–epoxy composite, the optimum combination should be S = 3000 rpm, FR = 800 mm/min, DOC = 0.25 mm, and FN = 6. Similarly, to achieve the minimum surface roughness value in the milling of carbon–epoxy composite, the optimum combination of parameters should be S = 600 rpm, FR = 100 mm/min, DOC = 0.25, and FN = 6. The average roughness values obtained during the milling of jute–epoxy composite and carbon–epoxy composites are 6.685 and 3.08 μm, respectively. In this present work, it is proved that the optimum combination of parameters to get the minimum surface roughness and the amount of surface roughness produced during milling are highly influenced by the type of reinforced material. The graphs are prepared for the entire range of input parameters to identify the intermediate Ra value at any input value without the use of software.
Molecular dynamics in multidimensional space explains how mutations affect the association path of neomycin to a riboswitch
Authors: Chyży Piotr , Kulik Marta , Shinobu Ai , Re Suyong , Sugita Yuji , Trylska Joanna
Published: April 2024

Riboswitches are messenger RNA (mRNA) fragments binding specific small molecules to regulate gene expression. A synthetic N1 riboswitch, inserted into yeast mRNA controls the translation of a reporter gene in response to neomycin. However, its regulatory activity is sensitive to single-point RNA mutations, even those distant from the neomycin binding site. While the association paths of neomycin to N1 and its variants remain unknown, recent fluorescence kinetic experiments indicate a two-step process driven by conformational selection. This raises the question of which step is affected by mutations. To address this, we performed all-atom two-dimensional replica-exchange molecular dynamics simulations for N1 and U14C, U14C

+

, U15A, and A17G mutants, ensuring extensive conformational sampling of both RNA and neomycin. The obtained neomycin association and binding paths, along with multidimensional free-energy profiles, revealed a two-step binding mechanism, consisting of conformational selection and induced fit. Neomycin binds to a preformed N1 conformation upon identifying a stable upper stem and U-turn motif in the riboswitch hairpin. However, the positioning of neomycin in the binding site occurs at different RNA–neomycin distances for each mutant, which may explain their different regulatory activities. The subsequent induced fit arises from the interactions of the neomycin’s N3 amino group with RNA, causing the G9 backbone to rearrange. In the A17G mutant, the critical C6-A17/G17 stacking forms at a closer RNA–neomycin distance compared to N1. These findings together with estimated binding free energies coincide with experiments and elucidate why the A17G mutation decreases and U15A enhances N1 activity in response to neomycin.
Metaphors for multiculturalism in the Canadian context
Authors: Shakoury Kayvan , Boers Frank
Published: April 2024

Although Canada is reputed for being a multicultural society, Canadians’ opinions vary regarding the extent to
which multiculturalism should be promoted. Examining metaphorical language in discourse about multiculturalism may reveal which
metaphors are typically used to endorse it and which ones are typically used to express a more skeptical stance. This study
analyzed 646 opinion pieces regarding multiculturalism published in Canadian newspapers. Linguistic metaphors were identified and
then grouped under themes. The texts were categorized according to the authors’ stance, and instantiations of the metaphor themes
were tallied to determine if some occur more frequently in discourse that promotes multiculturalism compared to discourse that
expresses reservations. Some metaphor themes were instantiated more often either in texts painting a positive picture of
multicultural society (e.g., a multicultural society is a varied, multi-component work of art or craft) or in ones
expressing reservations (e.g., multiculturalism is a destabilizing or divisive force). Such contrasts were nonetheless
attenuated by the way a single metaphor theme can be used to serve different rhetorical purposes. It also appears that writers are
not always aware of the entailments of the metaphors they use, especially if these are conventionalized phrases.
Supporting animals and veterans through enrichment: An exploratory study on a brief canine socializing intervention
Authors: Webberson Emily , Schroeder Katy , Binfet John-Tyler , Stellato Anastasia C.
Published: April 2024

Veterans pursuing post-secondary education may experience reintegration challenges and academic-related stress. To support student well-being, colleges and universities have begun to offer animal-assisted interventions (AAI); however, the influence of AAI programs on student veteran populations remains underexplored. Furthermore, the welfare impact of AAI programs on incorporating animals has begun to be assessed. As shelter dogs can benefit from human interaction, a mixed-methods design was used to assess if dogs and student veterans could benefit from participating in a brief 30-min unstructured interaction. We aimed to identify whether: the interaction influenced veteran reported mood state, the dog and the interaction activities completed influenced veteran experience, and the interaction influenced shelter dog behavior. Thirty veterans (
M
age
= 34,
SD
= 9.2; 24 males, 4 females) enrolled in a southern United States mid-size public university participated along with screened shelter dogs (
N
= 30,
M
age
= 2,
SD
= 0.9; 17 males, 13 females). Veterans were instructed to engage in the activities of their choosing (i.e., petting, playing, talking, providing treats, brushing) with a shelter dog. To assess changes in veteran mood, a pictorial self-report scale (assessing arousal (activated, deactivated), and valence (pleasant, unpleasant)) was completed pre- and post-interaction. Dog behavior was measured in shelter before the interaction and during the beginning, middle, and end of the interaction. Results reveal veterans reported pleasant post-interaction mood states, an overall positive experience and activity enjoyment. Qualitative results indicated that veterans perceived the dog behavior to be the most memorable aspect of participation, positively influencing their overall interaction experience. Dogs entered the interaction with more behavioral displays of fear (e.g., reduced posture), general activity (e.g., jumping), and soliciting contact behaviors (e.g., soliciting play), with all behavioral activity reducing halfway into the interaction, potentially suggesting increased relaxation over the course of the interaction. Observed decreases in dog fear behavior and veteran reported activity enjoyment suggests benefits for shelter dogs and student veterans.
BRAND: a platform for closed-loop experiments with deep network models
Authors: Ali Yahia H , Bodkin Kevin , Rigotti-Thompson Mattia , Patel Kushant , Card Nicholas S , Bhaduri Bareesh , Nason-Tomaszewski Samuel R , Mifsud Domenick M , Hou Xianda , Nicolas Claire , Allcroft Shane , Hochberg Leigh R , Au Yong Nicholas , Stavisky Sergey D , Miller Lee E , Brandman David M , Pandarinath Chethan
Published: April 2024

Objective. Artificial neural networks (ANNs) are state-of-the-art tools for modeling and decoding neural activity, but deploying them in closed-loop experiments with tight timing constraints is challenging due to their limited support in existing real-time frameworks. Researchers need a platform that fully supports high-level languages for running ANNs (e.g. Python and Julia) while maintaining support for languages that are critical for low-latency data acquisition and processing (e.g. C and C++). Approach. To address these needs, we introduce the Backend for Realtime Asynchronous Neural Decoding (BRAND). BRAND comprises Linux processes, termed nodes, which communicate with each other in a graph via streams of data. Its asynchronous design allows for acquisition, control, and analysis to be executed in parallel on streams of data that may operate at different timescales. BRAND uses Redis, an in-memory database, to send data between nodes, which enables fast inter-process communication and supports 54 different programming languages. Thus, developers can easily deploy existing ANN models in BRAND with minimal implementation changes. Main results. In our tests, BRAND achieved <600 microsecond latency between processes when sending large quantities of data (1024 channels of 30 kHz neural data in 1 ms chunks). BRAND runs a brain-computer interface with a recurrent neural network (RNN) decoder with less than 8 ms of latency from neural data input to decoder prediction. In a real-world demonstration of the system, participant T11 in the BrainGate2 clinical trial (ClinicalTrials.gov Identifier: NCT00912041) performed a standard cursor control task, in which 30 kHz signal processing, RNN decoding, task control, and graphics were all executed in BRAND. This system also supports real-time inference with complex latent variable models like Latent Factor Analysis via Dynamical Systems. Significance. By providing a framework that is fast, modular, and language-agnostic, BRAND lowers the barriers to integrating the latest tools in neuroscience and machine learning into closed-loop experiments.
Extending the understanding of Shannon’s safe stimulation limit for platinum electrodes: biphasic charge-balanced pulse trains in unbuffered saline at pH = 1 to pH = 12
Authors: Niederhoffer Thomas , Vanhoestenberghe Anne , Lancashire Henry T
Published: April 2024

Objective. In neural electrical stimulation, safe stimulation guidelines are essential to deliver efficient treatment while avoiding neural damage and electrode degradation. The widely used Shannon’s limit, k, gives conditions on the stimulation parameters to avoid neural damage, however, underlying damage mechanisms are not fully understood. Moreover, the translation from bench testing to in vivo experiments still presents some challenges, including the increased polarisation observed, which may influence charge-injection mechanisms. In this work, we studied the influence on damage mechanisms of two electrolyte parameters that are different in vivo compared to usual bench tests: solution pH and electrolyte gelation. Approach. The potential of a platinum macroelectrode was monitored in a three-electrode setup during current-controlled biphasic charge-balanced cathodic-first pulse trains. Maximum anodic and cathodic potential excursions during pulse trains were projected on cyclic voltammograms to infer possible electrochemical reactions. Main results. In unbuffered saline of pH ranging from 1 to 12, the maximum anodic potential was systematically located in the oxide formation region, while the cathodic potential was located the molecular oxygen and oxide reduction region when k approached Shannon’s damage limit, independent of solution pH. The results support the hypothesis that Shannon’s limit corresponds to the beginning of platinum dissolution following repeated cycles of platinum oxidation and reduction, for which the cathodic excursion is a key tipping point. Despite similar potential excursions between solution and gel electrolytes, we found a joint influence of pH and gelation on the cathodic potential alone, while we observed no effect on the anodic potential. We hypothesise that gelation creates a positive feedback loop exacerbating the effects of pH ; however, the extent of that influence needs to be examined further. Significance. This work supports the hypothesis of charge injection mechanisms associated with stimulation-induced damage at platinum electrodes. The validity of a major hypothesis explaining stimulation-induced damage was tested and supported on a range of electrolytes representing potential electrode environments, calling for further characterisation of platinum dissolution during electrical stimulation in various testing conditions.
Towards ASSR-based hearing assessment using natural sounds
Authors: Sergeeva Anna , Christensen Christian Bech , Kidmose Preben
Published: April 2024

Objective. The auditory steady-state response (ASSR) allows estimation of hearing thresholds. The ASSR can be estimated from electroencephalography (EEG) recordings from electrodes positioned on both the scalp and within the ear (ear-EEG). Ear-EEG can potentially be integrated into hearing aids, which would enable automatic fitting of the hearing device in daily life. The conventional stimuli for ASSR-based hearing assessment, such as pure tones and chirps, are monotonous and tiresome, making them inconvenient for repeated use in everyday situations. In this study we investigate the use of natural speech sounds for ASSR estimation. Approach. EEG was recorded from 22 normal hearing subjects from both scalp and ear electrodes. Subjects were stimulated monaurally with 180 min of speech stimulus modified by applying a 40 Hz amplitude modulation (AM) to an octave frequency sub-band centered at 1 kHz. Each 50 ms sub-interval in the AM sub-band was scaled to match one of 10 pre-defined levels (0–45 dB sensation level, 5 dB steps). The apparent latency for the ASSR was estimated as the maximum average cross-correlation between the envelope of the AM sub-band and the recorded EEG and was used to align the EEG signal with the audio signal. The EEG was then split up into sub-epochs of 50 ms length and sorted according to the stimulation level. ASSR was estimated for each level for both scalp- and ear-EEG. Main results. Significant ASSRs with increasing amplitude as a function of presentation level were recorded from both scalp and ear electrode configurations. Significance. Utilizing natural sounds in ASSR estimation offers the potential for electrophysiological hearing assessment that are more comfortable and less fatiguing compared to existing ASSR methods. Combined with ear-EEG, this approach may allow convenient hearing threshold estimation in everyday life, utilizing ambient sounds. Additionally, it may facilitate both initial fitting and subsequent adjustments of hearing aids outside of clinical settings.