bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase field modeling of ductile fracture and application in metal forming
Authors: WASEEM S.
Published: April 2023

Abstract. A phase field model for ductile fracture is coupled with the Modified Mohr Coulomb (MMC) model for plastic damage evolution and subsequent crack growth. An energy-based damage threshold is applied to control degradation due to ductile damage. The model is implemented through a user subroutine. MMC parameters from the literature are utilized and found to be compatible with the model, accurately reproducing material response curves in a variety of loading conditions for 6016-T4 aluminum alloy. The influence of model parameters is demonstrated and additionally the Nakazima test is simulated to demonstrate the capability of the model predicting the formability of the material through a failure locus. The model is found capable of reproducing experimentally observed crack paths and quantitative material behavior.
A phase-field numerical framework to study ductile damage to fracture transition: An application to material forming processes
Authors: PINO MUÑOZ D.
Published: April 2023

Abstract. In this work we present a phase-field based method to accurately predict the nucleation and evolution of damage. The damage pattern is then used as a criterion for automatic, remeshing-based, 3D crack insertion and propagation. The proposed framework has been implemented in Forge® finite element software and it offers a robust numerical tool for the modeling of damage to fracture transition in complex industrial processes. A bar shearing simulation will be used to show the robustness and efficiency of the approach. The flexibility of the approach is presented through the use of different damage criteria introduced into the phase-field formulation.
Surface topography investigation during nanosecond pulsed laser engraving of SAE304 stainless steel
Authors: NIKOLIDAKIS E.
Published: April 2023

Abstract. Laser engraving process is widely used for various industrial applications, such as the creation of small and complex geometries with ultra-high precision. As surface topography can affect the functionality of produced surfaces in various ways, it is required to carry out comprehensive experimental work in order to correlate the laser engraving process parameters with surface topography characteristics. In the current paper, the surface topography of SAE304 stainless steel specimens in respect to laser power, scanning speed and pulse repetition rate is studied through microscope observations. The findings indicate that the scanning speed is the most dominant parameter regarding surface roughness and from the viewpoint of surface quality, it is suggested that higher scanning speed, lower power and pulse repetition rate values should be employed.
Coefficient of friction of cemented carbides machined by sinking EDM
Authors: PETERSEN T.
Published: April 2023

Abstract. Cemented carbides possess properties that predestine them as a durable tool. However, these properties hinder conventional machining, which is why Electrical Discharge Machining (EDM) is a promising alternative. Three different EDMed cemented carbides were compared with a ground surface in a pin-on-disk test setup. They were evaluated under dry and lubricated conditions with two distinct antibody materials. The tests did not reveal a correlation between the surface roughness of the cemented carbide pins and the coefficient of friction. However, some test sets yielded very different results, which is why particular considerations should be made with new sliding compositions.
Analysis of additively manufactured anisotropic microstructures through crystal plasticity frameworks
Authors: BULUT O.
Published: April 2023

Abstract. In additive manufacturing processes, the resulting products might have highly anisotropic granular morphologies due to the complex thermal history. The most commonly observed morphology is columnar structure. The resulting morphology of grains is accompanied by the orientation alignment leading to plastic anisotropy. It has been shown in a recent study through local crystal plasticity calculations that the morphology evolution does not influence the mechanical behavior without considering the texture evolution [1]. However, the local frameworks do not consider the effect of the grain size which could be complicated due to high aspect ratio of the grains. This study aims to investigate the influence of the developed anisotropic grain structure on the macroscopic response through both local and non-local crystal plasticity frameworks to address the capacity of these models in capturing the realistic response. An additional subroutine is implemented (see [2]) into the crystal plasticity frameworks to obtain the slip resistance values at each material point based on grain geometries and misorientations. This allows the size dependent yielding of the crystals.
Viscoelastic characterization of reformable epoxy vitrimers composites
Authors: PALMIERI B.
Published: April 2023

Abstract. Epoxy Vitrimers are gathering attention as a development in the field of more easily re-processable and self-healing thermosets. Incorporating a catalyst should activate the transesterification reaction within the polymeric macromolecule inducing topological modification of the network. Reacting epoxy precursors with suitable anhydrides and acids will promote exchange reactions between esters and beta-hydroxyls, adding the vitrimeric behaviour. In the present work, a commercial epoxy system suitable for CFRP manufacturing has been modified to induce vitrimeric behaviour by exploiting the catalytic activity towards the transesterification reaction of Zn2+. Creep experiments confirm that the resin starts to flow above a critical “Vitrimeric” temperature (Tv). Moreover, the thermoformability of vitrimer-CFRP has been investigated by reprocessing CFRP coupons.
Energy and resource-efficient forming of gas cylinders by friction-spinning
Authors: DAHMS F.
Published: April 2023

Abstract. Friction-spinning as an innovative incremental forming process enables large degrees of deformation in tube and sheet metal-forming due to a self-induced heat generation in the forming zone. This paper presents new process designs for energy and resource-efficient forming of gas cylinders by friction-spinning without the use of an external heat supply. The self-generated heat enables friction-spinning process to reduce the energy demand in the manufacture of gas cylinders, which are usually manufactured with external heat (mostly fossil fuels), by 95 %. Typical gas cylinder contours, such as flattened and spherical bottom ends and cylinder necks, are manufactured by friction-spinning of AW 6060 tubular profiles with specifically designed tool path strategies. It is shown that friction-spinning enables the manufacture of typical gas cylinder contours with sufficient wall thickness and the required gas tightness without the input of external heat. Thus, this process can contribute to an increase in the energy and resource efficiency of forming processes.
Energy measurements and LCA of remanufactured automotive steel sheets
Authors: FARIOLI D.
Published: April 2023

Abstract. New paradigms based on Circular Economy (CE) principles are needed for boosting the ecological transition and improving the energy and material efficiency. In this paper, a novel remanufacturing process chain for End-of-Life (EoL) automotive panels is first presented. The core of the recycling strategy is the reshaping of curved EoL automotive sheets through flattening by means of a hydraulic press. Flattening experiments together with press power consumption measurements have been performed on thin steel parts. While the experimental procedure demonstrated the technical feasibility of flattening “small-scale” steel parts, a more complete analysis on environmental sustainability was required. For this purpose, a Life Cycle Assessment (LCA) of the remanufacturing process chain proposed was set up. The results of the study demonstrated that flattening is a viable solution for reshaping EoL automotive panels, and that, for one kg of reshaped steel, approximately 2.2 kg CO2 and 24 MJ could be saved.
Sustainable tool technology: Wood-based forming tools
Authors: GEUEKE M.
Published: April 2023

Abstract. Conventional, dies are manufactured subtractive for sheet metal forming. Beside the forming process, high tooling costs, material exertion and energy consumption, the die production offers chances for economic improvements. Especially, individualization and mass customization for small batch series require sustainable low-cost tooling approaches, where sustainable advances through biologicalization may offer new possibilities. In this work, sheet metal forming tools are manufactured by laminated black locust dies to reduce the overall ecological impact. The deformation and wearing behavior of the wooden tools is investigated during a drawing operation for low batch size of an automotive conventional sheet material.
Microstructure analysis of hybrid aluminum parts from recycled EN AW-6082 and EN AW-7075 chips
Authors: URSINUS J.
Published: April 2023

Abstract. In order to promote aluminum scrap recycling and reduce remelting losses, solid-state recycling processes are subject to increasing academic attention. These processes range from severe plastic deformation (SPD) to diffusion-based processes like field-assisted sintering (FAST). In this study, a FAST-based recycling route consisting of precompaction, FAST, and impact extrusion of dry machined EN AW-6082 and EN AW-7075 aluminum chips was used to create multi-material parts from different aluminum alloys. To examine the effect on the resulting part quality, two different hybrid material layouts were created during cold compaction of the chips. The subsequent sintering process took place in a field-assisted sintering (FAST) machine at 400°C and 500°C for a duration of 5 min under a pressure of 85 MPa, allowing for the analysis of inter-chip diffusion. These sintered blanks were then cold-formed by impact extrusion. Metallographic and computed tomography analyses as well as hardness measurements were performed for property evaluation before and after heat-treatment.
Monitoring of fluctuating material properties for optimizing sheet-metal forming processes: a systematic literature review
Authors: ORTJOHANN L.
Published: April 2023

Abstract. Material properties can vary both along a sheet-metal coil and from coil to coil despite tight tolerances influencing the process stability of sheet-metal processes and the part quality, which leads to rejects and machine downtime [1]. This significantly affect the economic efficiency of the process. Monitoring fluctuations in material characteristics at regular intervals along sheet-metal coils is enabled directly by non-destructive testing (NDT) before the process offering conclusions on the material properties. Another material monitoring technique arises from monitoring process conditions of the upstream processes, e.g., cold rolling, leading indirectly to insights on material properties. In this work, a systematic literature review (SLR) [2] is conducted to investigate recent approaches for material monitoring and for the utilization of resulting material data for optimizing different sheet-metal forming processes. Existing approaches for different sheet-metal forming processes are critically appraised. Based on the SLR research gaps are revealed and research opportunities, e.g., arising from a potential transfer of existing solutions between different forming processes and recent advances in data-driven methods, are identified.
Fine blanking of pre-hardened high manganese steel to investigate the sheared surface hardening and part quality
Authors: SCHWEINSHAUPT F.
Published: April 2023

Abstract. Fine blanking is a highly productive process for manufacturing of high accuracy sheet metal parts with functional surfaces. The specific process characteristic leads to high forming in the shear zone and an associated strain hardening of the sheared functional surfaces. Utilization of the process-immanent sheared surface hardening can reduce time and resources of downstream heat treatment processes such as case hardening. High Manganese Steels (HMnS) are characterized by a high strain hardening capacity due to the deformation mechanisms of twinning and transformation induced plasticity occurring during forming. As a result of high tensile strengths, HMnS are suitable as lightweight materials, but often exhibit a relatively low yield strength in terms of structural design features. One approach for increasing the strength values without changing the alloy design is a forming-induced strain hardening of the semi-finished sheet metal by means of upsetting. Therefore, this paper deals with an experimental investigation of the influence of pre-hardening on the blanked part properties during fine blanking of HMnS X40MnCrAlV19-2 LY (1.7401). For this purpose, sheet blanks were strain hardened by means of flat coining and subsequently fine blanked with an analog geometry representing tribologically stressed functional surfaces. Relevant functional surfaces were then analyzed by means of microhardness measurements with regard to the sheared surface hardening as well as characterized in terms of the quality-determining attributes die roll and clean-shear area. Due to the deformation mechanism of twinning, fine blanking of pre-hardened HMnS resulted in a combination of process-immanent high sheared surface hardening and increased yield strength with simultaneous optimal functional surface quality.
Thermo-chemical modeling and simulation of glass/elium® acrylic thermoplastic resin composites
Authors: DENIS Y.
Published: April 2023

Abstract. The recyclability limitations of wind blades significantly reduce their environmental benefit as a green energy source. Therefore, the use of new and sustainable materials is crucial. The Zero wastE Blade ReseArch project (ZEBRA), led by the French technical research center IRT Jules Verne, is looking to accelerate the industry transition to circular economy by designing and manufacturing the first 100% recyclable wind blades using the thermoplastic resin Elium®, developed by Arkema, with a consortium regrouping: LM Wind Power, Arkema, CANOE, Owens Corning, ENGIE and Suez. In this work, the polymerization kinetics of the reactive thermoplastic resin Elium® was characterized through isothermal and dynamic Differential Scanning Calorimetry (DSC) tests. The experimental curves are fitted to two different models from the literature; then the model parameters are identified and used as input to simulations. One model is selected and evaluated using a PAM-RTM© simulation for pure resin and the infusion of Owens Corning glass/Elium® composites [1]. The numerical results are compared with experimental data collected from Vacuum-assisted resin infusion (VARI) tests with the help of a robust monitoring system [2]. Then the model is used to predict the flow and polymerization behavior for thick and more complex parts.
Phenomena of tool adhesion at elevated temperature in V-groove friction test of AA7075
Authors: FUNAZUKA T.
Published: April 2023

Abstract. 7000 series aluminum alloys are high-strength alloys used in various lightweight products in the transportation equipment and aerospace industries. AA7075 extrusions are expected to find further applications in multiple fields, including aircraft parts, automotive parts, and sporting goods. However, the high deformation resistance and surface cracking defects caused by tool galling and adhesion have resulted in extremely low productivity. In this study, the V-groove compression test was proposed as a method to determine the coefficient of friction in hot metal forming. Using AA7075 as the experimental material, what did the V-groove compression test at various temperatures to compare the results with calibration curves created from the numerical analysis and observe the growth of adhesion.
Yield stress and work hardening behavior of extruded AA6082 profiles under different homogenization and extrusion conditions
Authors: WILLIAMS W.M.
Published: April 2023

Abstract. The mechanical properties of extruded AlMgSi alloys are affected by the applied thermo-mechanical parameters employed during the entire production process. In the following, the effect of different extrusion speeds and homogenization conditions paired with either air or water quenching, is examined on four different sets of rectangular hollow AA6082-T4 profiles. These profiles were fabricated and extruded under industrial conditions and selected cross sections of each profile were examined by optical microscopy to determine the microstructure and level of recrystallization. Uniaxial tension testing was used to explore the effect of homogenization conditions and extrusion cooling rate on mechanical properties. Tensile tests showed that the water-quenched extrusions had a higher yield and ultimate strength compared to air-quenched extrusions. Moreover, samples that had a recrystallized microstructure typically showed a larger standard deviation of mechanical properties, which may lead to product quality and consistency issues for metal forming operations. Overall, the present work provides a more in-depth understanding of how the selected thermo-mechanical parameters affect the resulting properties of such profiles. This can further contribute to expanding the potential for effective accommodation of extrusion parameters for zero-defect products.
Experimental analysis and modeling of the recrystallization behaviour of a AA6060 extruded profile
Authors: NEGOZIO M.
Published: April 2023

Abstract. The microstructure of Al-Mg-Si alloys is gaining nowadays an increasing industrial interest because it influences the strength, crash, corrosion and esthetic properties of the extruded profiles. In order to investigate and predict the recrystallization behaviour in the extrusion of 6XXX aluminum alloys, experimental and numerical activities are still needed. In this work, the extrusion of an industrial-scale AA6060 aluminum alloy hollow profile was carried out. An innovative recrystallization model was developed and optimized by comparing the microstructural data experimentally acquired with the outputs of the simulation performed using the Finite Element commercial code Qform Extrusion. A good correlation between numerical prediction and experimental data was found, thus proving the reliability of the proposed AA6060 recrystallization model.
Investigation of the skin contamination predictability by means of QForm UK extrusion code
Authors: KNIAZKIN I.
Published: April 2023

Abstract. The paper presents an innovative approach implemented in QForm UK Extrusion FEM software to analyse one of the core defects encountered in profile extrusion known as billet skin defect. The validation of the algorithm has been performed based on a number of experimental case studies taken from the literature [1,2]. Additionally, the sensitivity of the accuracy of the results to the variation in initial parameters has been analysed for both types of profile shapes: solid and hollow. Based on this, practical recommendations have been formalised for the successful industrial use of the presented algorithm.
Evolution of microstructure during hot incremental disk rolling of a nickel-based super-alloy
Authors: DINÇER M.S.
Published: April 2023

Abstract. In the aerospace industry, the turbine disk plays a crucial role. Controlling the average grain size during the hot forming of nickel-based superalloys such as Inconel 718 is critical for turbine disk production. Recrystallization is primarily responsible for evolution of microstructure during a hot forming process. In the current study, Finite Element Method (FEM) is employed to assess grain size evolution during an incremental disk rolling process. FEM simulations are used to obtain temperature, strain and strain rate distributions. Then, utilizing these deformation distributions, recrystallization and consequent average grain size distributions are calculated using Johnson-Mehl-Avrami-Kolmogorov (JMAK) equations. Simulations are conducted for different spindle rates of the workpiece. This process is sensitive to the temperature and meta-dynamic recrystallization. Results show that temperature increases with the spindle rate due to the inelastic heat generation. Also a higher grain size variation through thickness is obtained for the simulation with lower spindle rate since meta-dynamic recrystallization fraction is higher.
Influence of process parameters and process set-up on damage evolution during stretch drawing of u-shaped profiles
Authors: MÜLLER M.
Published: April 2023

Abstract. The damage state in the form of voids and lattice defects of a sheet metal component has a substantial impact on the performance of a component in service regarding fatigue or crash behaviour. Therefore, managing the damage evolution during forming, especially the accumulation and distribution of damage, by targeted changes of the process parameters and set-up enables to improve component performance by influencing the stress-strain state [1]. The evolution of the stress-strain state during the forming process and along the process route represents the most significant factor influencing the resulting damage state. This paper focuses on the influence of the damage state of sheet metal components in order to improve the performance of a component regarding fatigue and crash behavior. Considering a variation of the process parameter (drawing die radius) and change in process set-up (singlestep, multistep, reverse stretch drawing) the damage accumulation and distribution within the component is analyzed using a calibrated LEMAITRE damage model. For the consideration of this paper, an u-shaped geometry of dual phase steel DP800, which is often found as an element in vehicle body construction, is used.
Investigation of the influence of loading direction after pre-forming on the formability and mechanical properties of DP600
Authors: NORZ R.
Published: April 2023

Abstract. The material behaviour after non-proportional strain paths is subject of numerous current investigations. These investigations show that in addition to the stress state, a change in the direction of loading also has a significant influence on the material behaviour. In this work, the influence of non-proportional strain paths on the mechanical properties such as tensile strength, uniform strain, elongation at fracture and yield strength as well as the influence on formability is determined. For this purpose, a dual-phase steel CR330Y590-DP, with a thickness of 0.8 mm, is investigated in more detail. The material is pre-strained to different strain values and then further examined with Nakajima and tensile tests. The influence of the loading direction is determined by five different post-strain directions (0°, 22,5°, 45°, 67.5°and 90°) to the initial pre-strain direction. In addition to the method according to the standard, the yield strength is determined by a temperature-dependent determination method, which is based on the thermoelastic effect. This method has already been qualified for simple uniaxial tensile tests and a relation to the microstructural behaviour was proven. Thus, it provides valuable conclusions on the microstructural behavior for the tests performed within this study with a change in the loading direction.
Design of a new simulative tribotest for warm forming applications having high contact pressure and surface enlargement
Authors: GALDOS L.
Published: April 2023

Abstract. Many tribological tests have been developed in the last decades to emulate real cold forging processes at laboratory conditions and to obtain friction coefficients at different process conditions. In this paper a new tribotester is designed and numerically validated to reach extreme contact conditions, high normal contact pressure and surface enlargement, for warm temperature testing of lubricants starting from material in the form of thick sheets or precuts. The numerical simulations prove that this is possible by the use of a combined bending and ironing test.
Validity of Electronic Module Based on Process Oriented Guided Inquiry Learning (POGIL) Model to Train Students' Science Process Skills
Authors: Oktaria S. A. , Rahmad M. , Anwar L.
Published: April 2023

The research aimed to validate the electronic module (e-module) based on the process oriented guided inquiry learning (POGIL) model on the topic of Vibrations, Waves, and Sounds in junior high school. The e-module developed was expected to help students learn independently and practice the science process skills. The research method was a research and development in accordance with the Plomp (2013) model. There were three validation components in the developed e-module\, i.e.: material, pedagogical, and media validation. This e-module has been validated based on the average assessment score given by the validators. The validation results of the material, pedagogical, and media were in a very valid category, with a percentage of 91.6%, 88.9%, and 89.8%, respectively. In short, the developed e-module produced excellent assessment results. Moreover, it was feasible for use in the science learning process of junior high school and can train students' science process skills
Кинетика изменения оптической прозрачности нанопленок палладия при взаимодействии с водородом
Authors: Шутаев В.А. , Гребенщикова Е.А. , Матвеев В.А. , Губанова Н.Н. , Яковлев Ю.П.
Published: April 2023

The kinetics of changing in optical transmittance of palladium (Pd) nanolayers (about 10 nm thick, deposited on object glass substrates by thermal evaporation in vacuum) in hydrogen flow (100 vol.%) in the temperature range of 300-335 K are studied. It is shown that the rate of changing of palladium optical transmittance at hydrogen flow rises linearly with increasing the temperature due to sorption of hydrogen by Pd layer. The rate of changing in optical transmittance of Pd layer during sorption and desorption of hydrogen is established to rise by about one order with increasing the temperature from 300 to 335 K. The curves describing the changing in optical transmittance of palladium nanolayer during hydrogen desorption have two distinct sections: linear and nonlinear. The linear section of the curve weakly depends on temperature, while the nonlinear section sharply rises with increasing the temperature. Such the changing of the rate in optical transmittance can be associated with phase transition from β- to α-phase during hydrogen desorption from palladium.
Exploring the Relationship between Attitudes and Blood Glucose Control among Patients with Type 2 Diabetes Mellitus in Chamchamal Town, Kurdistan, Iraq
Authors: Mohammed Hawar Mardan , Lafi Samir Yonis
Published: April 2023

Background: Diabetes mellitus type 2 is an endocrine disorder characterized by a progressive elevation in blood glucose levels. It is a persistent and incapacitating illness that may result in mortality if not properly managed. Objectives: The objective of this research is to explore the relationship between the attitudes of individuals with type 2 diabetes mellitus and their ability to regulate blood glucose levels. In particular, the study aims to investigate the potential correlation between participants’ attitudes and their capacity to manage blood glucose levels following their participation in an educational program. Moreover, the research seeks to analyze the association between individuals’ attitudes and diabetes control. Ultimately, the study intends to evaluate the levels of participants’ attitudes through appropriate measures. Materials and Methods: The study is designed as a cross-sectional investigation and utilizes data from a diabetic outpatient center in Chamchamal. The study population consists of outpatients from the evening public clinic and chronic disease control center. Participants are required to complete questionnaires on their diabetes attitude. The study was conducted between August 11, 2019, and January 5, 2022. To explore the efficacy of the attitude with diabetes control, we used a correlation coefficient test and a t-test with P-value of 0.05 as our alpha level of significance. Results and Conclusion: The study found that the majority of patients with type 2 diabetes mellitus had low levels of educational attainment, were married and had insufficient monthly income. In addition, 85% of the patients reported not smoking, and 48.3% were classified as overweight. These findings highlight the need for health-care providers to consider sociodemographic factors in the management of diabetes mellitus.
A Novel Capacity-Strengthening Intervention for Frontline Harm Reduction Workers to Support Pre-exposure Prophylaxis Awareness-Building and Promotion Among People Who Use Drugs: Formative Research and Intervention Development
Authors: Glick Jennifer L , Zhang Leanne , Rosen Joseph G , Yaroshevich Karla , Atiba Bakari , Pelaez Danielle , Park Ju Nyeong
Published: April 2023

Background

HIV prevalence among people who use drugs (PWUD) in Baltimore, Maryland, is higher than among the general population. Pre-exposure prophylaxis (PrEP) is a widely available medication that prevents HIV transmission, yet its usefulness is low among PWUD in Baltimore City and the United States. Community-level interventions to promote PrEP uptake and adherence among PWUD are limited.

Objective

We describe the development of a capacity-strengthening intervention designed for frontline harm reduction workers (FHRWs) to support PrEP awareness-building and promotion among PWUD.

Methods

Our study was implemented in 2 phases in Baltimore City, Maryland. The formative phase focused on a qualitative exploration of the PrEP implementation environment, as well as facilitators and barriers to PrEP willingness and uptake, among cisgender women who use drugs. This work, as well as the existing literature, theory, and feedback from our community partners, informed the intervention development phase, which used an academic-community partnership model. The intervention involved a 1-time, 2-hour training with FHRWs aimed at increasing general PrEP knowledge and developing self-efficacy promoting PrEP in practice (eg, facilitating PrEP dialogues with clients, supporting client advancement along a model of PrEP readiness, and referring clients to PrEP services). In a separate paper, we describe the conduct and results of a mixed methods evaluation to assess changes in PrEP-related knowledge, attitudes, self-efficacy, and promotion practices among FHRWs participating in the training.

Results

The pilot was developed from October to December 2021 and implemented from December 2021 through April 2022. We leveraged existing relationships with community-based harm reduction organizations to recruit FHRWs into the intervention. A total of 39 FHRWs from 4 community-based organizations participated in the training across 4 sessions (1 in-person, 2 online synchronous, and 1 online asynchronous). FHRW training attendees represented a diverse range of work cadres, including peer workers, case managers, and organizational administrators.

Conclusions

This intervention could prevent the HIV burden among PWUD by leveraging the relationships that FHRWs have with PWUD and by supporting advancement along the PrEP continuum. Given suboptimal PrEP uptake among PWUD and the limited number of interventions designed to address this gap, our intervention offers an innovative approach to a burgeoning public health problem. If effective, our intervention has the potential to be further developed and scaled up to increase PrEP awareness and uptake among PWUD worldwide.
Effectiveness of a Mindfulness Meditation App Based on an Electroencephalography-Based Brain-Computer Interface in Radiofrequency Catheter Ablation for Patients With Atrial Fibrillation: Pilot Randomized Controlled Trial
Authors: He Ying , Tang Zhijie , Sun Guozhen , Cai Cheng , Wang Yao , Yang Gang , Bao ZhiPeng
Published: April 2023

Background

Radiofrequency catheter ablation (RFCA) for patients with atrial fibrillation (AF) can generate considerable physical and psychological discomfort under conscious sedation. App-based mindfulness meditation combined with an electroencephalography (EEG)-based brain-computer interface (BCI) shows promise as effective and accessible adjuncts in medical practice.

Objective

This study aimed to investigate the effectiveness of a BCI-based mindfulness meditation app in improving the experience of patients with AF during RFCA.

Methods

This single-center pilot randomized controlled trial involved 84 eligible patients with AF scheduled for RFCA, who were randomized 1:1 to the intervention and control groups. Both groups received a standardized RFCA procedure and a conscious sedative regimen. Patients in the control group were administered conventional care, while those in the intervention group received BCI-based app–delivered mindfulness meditation from a research nurse. The primary outcomes were the changes in the numeric rating scale, State Anxiety Inventory, and Brief Fatigue Inventory scores. Secondary outcomes were the differences in hemodynamic parameters (heart rate, blood pressure, and peripheral oxygen saturation), adverse events, patient-reported pain, and the doses of sedative drugs used in ablation.

Results

BCI-based app–delivered mindfulness meditation, compared to conventional care, resulted in a significantly lower mean numeric rating scale (mean 4.6, SD 1.7 [app-based mindfulness meditation] vs mean 5.7, SD 2.1 [conventional care]; P=.008), State Anxiety Inventory (mean 36.7, SD 5.5 vs mean 42.3, SD 7.2; P<.001), and Brief Fatigue Inventory (mean 3.4, SD 2.3 vs mean 4.7, SD 2.2; P=.01) scores. No significant differences were observed in hemodynamic parameters or the amounts of parecoxib and dexmedetomidine used in RFCA between the 2 groups. The intervention group exhibited a significant decrease in fentanyl use compared to the control group, with a mean dose of 3.96 (SD 1.37) mcg/kg versus 4.85 (SD 1.25) mcg/kg in the control group (P=.003).The incidence of adverse events was lower in the intervention group (5/40) than in the control group (10/40), though this difference was not significant (P=.15).

Conclusions

BCI-based app–delivered mindfulness meditation effectively relieved physical and psychological discomfort and may reduce the doses of sedative medication used in RFCA for patients with AF.

Trial Registration

ClinicalTrials.gov NCT05306015; https://clinicaltrials.gov/ct2/show/NCT05306015
Fitbit Data to Assess Functional Capacity in Patients Before Elective Surgery: Pilot Prospective Observational Study (Preprint)
Authors: Angelucci Alessandra , Greco Massimiliano , Canali Stefano , Marelli Giovanni , Avidano Gaia , Goretti Giulia , Cecconi Maurizio , Aliverti Andrea
Published: April 2023

BACKGROUND

Preoperative assessment is crucial to prevent the risk of complications of surgical operations and is usually focused on functional capacity. The increasing availability of wearable devices (smartwatches, trackers, rings, etc) can provide less intrusive assessment methods, reduce costs, and improve accuracy.

OBJECTIVE

The aim of this study was to present and evaluate the possibility of using commercial smartwatch data, such as those retrieved from the Fitbit Inspire 2 device, to assess functional capacity before elective surgery and correlate such data with the current gold standard measure, the 6-Minute Walk Test (6MWT) distance.

METHODS

During the hospital visit, patients were evaluated in terms of functional capacity using the 6MWT. Patients were asked to wear the Fitbit Inspire 2 for 7 days (with flexibility of –2 to +2 days) after the hospital visit, before their surgical operation. Resting heart rate and daily steps data were retrieved directly from the smartwatch. Feature engineering techniques allowed the extraction of heart rate over steps (HROS) and a modified version of Non-Exercise Testing Cardiorespiratory Fitness. All measures were correlated with 6MWT.

RESULTS

In total, 31 patients were enrolled in the study (n=22, 71% men; n=9, 29% women; mean age 76.06, SD 4.75 years). Data were collected between June 2021 and May 2022. The parameter that correlated best with the 6MWT was the Non-Exercise Testing Cardiorespiratory Fitness index (r=0.68; P<.001). The average resting heart rate over the whole acquisition period for each participant had r=−0.39 (P=.03), even if some patients did not wear the device at night. The correlation of the 6MWT distance with the HROS evaluated at 1% quantile was significant, with Pearson coefficient of −0.39 (P=.04). Fitbit step count had a fair correlation of 0.59 with 6MWT (P<.001).

CONCLUSIONS

Our study is a promising starting point for the adoption of wearable technology in the evaluation of functional capacity of patients, which was strongly correlated with the gold standard. The study also identified limitations in the availability of metrics, variability of devices, accuracy and quality of data, and accessibility as crucial areas of focus for future studies.
Quality and Usability of Mobile Fundus Camera for Schematic Eyes: A Comparative Analysis (Preprint)
Authors: Tengtrisorn Supaporn , Chirasatitsin Somyot , Kaeonarong Prawit , Gansawat Duangrat , Chaichulee Sitthichok , Chongsuvivatwong Virasakdi
Published: April 2023

BACKGROUND

Photographs or videos taken from a mobile phone with a +20-D lens can be an alternative to indirect ophthalmoscopy in mass screening and telemedicine.

OBJECTIVE

To develop a mobile fundus camera (MFC) that ensures eye screening with safety, ease of use, and high accuracy in detecting fundus lesions.

METHODS

From October 1st, 2021, to September 30th, 2022, we developed an MFC based on Samsung S21 and iPhone 12 mobile phones with four different types of connecting lenses. Ten ophthalmology personnel were trained to use the MFC on schematic eyes and evaluate the developed systems. The four schematic eyes had a normal fundus, diabetic retinopathy (DR), normal optic disc, and glaucomatous optic disc. The system safety was assessed based on the ISO 15004-2 Visible wavelength (400–700 nm). All users completed the Thai version of the Usability Experience Questionnaire (UEQ). The evaluation of image quality was based on the sharpness index (SI), disc-to-image ratio, and color discrimination, which included relative redness, red-green difference, and red-blue difference.

RESULTS

Our system satisfied the safety criteria. The mean UEQ scores for the overall MFCs were above average in the domains of attractiveness, dependability, stimulation, and novelty. However, the efficiency and perspicuity were below average. The MFC based on the Samsung S21 had a significantly better overall SI but poorer overall color discrimination power than that of the iPhone 12 (p < 0.05). The best SI was achieved using Samsung S21+Volk 28D, whereas iPhone 12+oDocs 20D provided the best color discrimination. Interparticipant differences were not statistically significant.

CONCLUSIONS

All the developed MFCs tested were safe and usable. Based on the SI criteria, the Samsung S21+ Volk 28D should be used for further development.
ПРОЕКТИРОВАНИЕ КОНЕЧНЫХ АВТОМАТОВ В ПРИЛОЖЕНИИ STATEFLOW СИСТЕМЫ MATLAB / SIMULINK С ПОСЛЕДУЮЩЕЙ РЕАЛИЗАЦИЕЙ В БАЗИСЕ ПЛИС
Authors: Строгонов А.
Published: April 2023

В статье описан пример проектирования конечных автоматов в приложении Stateflow системы визуально-­имитационного моделирования Matlab/Simulink с последующей генерацией HDL-кода.
Intervenciones en el paisaje urbano desde la funcionalidad ecológica
Authors: Castillo Guillermo
Published: April 2023

Las ciudades son responsables de generar grandes cantidades de emisiones globales de gases de efecto invernadero y del consumo de los recursos naturales disponibles, lo que impacta de manera negativa al medio ambiente. Es por eso que las intervenciones al paisaje de ecosistemas urbanos representan una estrategia viable para mejorar su funcionalidad ecológica y contribuir a la mitigación de los efectos del cambio climático. Para ello, es fundamental incorporar el papel de la riqueza de especies, la diversidad funcional y la complejidad espacial como lineamientos para el diseño de intervenciones paisajísticas urbanas, lo cual se explora en este texto.
The Influence of Multi-Walled Carbon Nanotubes Additives on Performance and Emission of CI Engine Using Blends of Non-Edible (Jatropha Methyl Esters) Biodiesel & Diesel
Authors: Maniar V. R. , Gori S. P.
Published: April 2023

Abstract: This paper investigates the performance and emission characteristics of single cylinder diesel engine under various concentration of Multiwalled Carbon Nanotube (MWCNT) in blends B20 and B30 biodiesel were investigated to establish the effect of MWCNT as nano-additive on the blends biodiesel used in diesel engine and aims to reduce the emissions of hydrocarbon and carbon monoxide into the atmosphere.
Peningkatan Pemahaman Masyarakat Melalui Sosialisasi Hukum tentang Akta Otentik
Authors: Putri Cyndiarnis Cahyaning
Published: April 2023

Akta merupakan suatu hal yang lazim dijumpai dalam kehidupan masyarakat sehari-hari. Namun sayangnya, masyarakat masih belum banyak mengetahui mengenai akta, terutama terhadap akta otentik. Sementara terdapat beberapa perbuatan hukum yang menurut peraturan perundang-undangan yang harus dibuat dalam bentuk akta otentik. Berdasarkan kepada latar belakang tersebut, Pengusul dalam pengabdian kepada masyarakat ini berfokus kepada peningkatan pemahaman masyarakat melalui sosialisasi hukum mengenai akta otentik yang dilakukan pada Dialog Hukum Radio Republik Indonesia Malang. Namun dikarenakan situasi pandemi Covid-19, sehingga dalam melaksanakan kegiatan pengabdian masyarakat ini dilakukan dengan metode teleconference. Dari kegiatan sosialisasi hukum ini diharapkan masyarakat akan memperoleh pemahaman mengenai akta otentik, serta mampu mengetahui perbedaan antara akta otentik dengan akta di bawah tangan beserta dengan akibat hukumnya masing-masing.
 
Increasing Public Understanding Through Legal Socialization on Authentic Deeds.
The deed is something that often being used in daily life. Unfortunately, people still do not aware about the deed, especially about the Authentic Deed. Some legal acts by the law are required to be written through Notarial Deed. Based on the background above, it is needed to establish a community service which focus on improving knowledge of the community through legal socialization of authentic deed and is done through Dialog Hukum Radio Republik Indonesia Malang. Due to the Covid-19 pandemic, this community service is done by using the teleconference method. It is hoped that the community will gain useful knowledge about authentic deed, and able to differentiate between authentic deed and private deed along with the legal consequences it brings.
Haemovigilance Programme of India: A brief Review on Musketeer of safe Blood Transfusion in India
Authors: Rashmi  , Heena
Published: April 2023

Haemovigilance contributes major importance in regard to safe blood transfusions and ensuring patient safety. With coherently scrutinizing adverse events in the transfusion chain, Haemovigilance aids a safer and effective blood donation and transfusion procedures. These days, adverse event tracking, investigation, and analysis create pertinent data for the quality cycle of blood collection facilities, transfusion laboratories, and transfusion institutions. This review article focuses on the requirement of Haemovigilance, the current status of Haemovigilance in India as well as the Haemovigilance Program of India (HvPI) with respect to blood transfusion.
The Semiosphere of Argumentation as Speech and Thought Activity
Authors: Kostyushkina Galina M. , Sverdlova Natalia A. , Mariasova Elena P.
Published: April 2023

The systemic nature of semiosphere organization correlates with the systemic nature of argumentation as human speech and thought activity. Argumentation is a part of semiotic continuum of human speech and thinking, forming complex subsystems of semiosphere. The paper aims at constructing the semiosphere of argumentation by identifying different approaches to its study. The authors conclude that argumentation as a logical-communicative process can be reviewed most clearly when analyzed in terms of S. Toulmin’s classification from logical, dialectical, rhetorical research perspectives. The functions of persuasion and the significance of the addressee are in this case prioritized. The pragma-dialectical approach used by the authors and its integrated nature of studying of argumentation as a speechthought activity, made it possible to transfer from logics and dialectics to cognitive-oriented research. Axioms (12), underlying approaches to the study of argumentation, were analyzed and classified according to the principles of action, practice, and activity, as applied to language, which has a speech-thought-activity character. Argumentation as a component of human thinking semiosphere is the most complex phenomenon given its multidimensional and multisystemic nature.
The Crimean Tatar World in the Novels of Recent Years (on the Literary Texts by Lyudmila Ulitskaya, Timur Pulatov, Renat Bekkin)
Authors: Keshfidinov Shevket R.
Published: April 2023

One of the main achievements of multiculturalism researchers is the proof of the need to reject hierarchy and the compelling demonstration of mutual influence and dependency of very different cultural systems. Complex processes of cultural interaction produce new meanings and new cultural codes, even beyond geographical and national boundaries. The article presents the novels by Lyudmila Ulitskaya, Timur Pulatov, and Renat Bekkin. These works refer to Crimean Tatars or based directly on this topic. The analysis of the proposed stories allows us to put the Crimean Tatar world into a broad cultural context and speak of the existence of a “Crimean Tatar text’’ in Russian literature. This solution, in turn, allows the addition of a number of patterns (symbols-images) — details of history and everyday life, cultural artifacts and features of the landscape, gastronomy and architecture — which form the concept of “local text’’.
Multilingual Communication in Francophone Bandes Dessinées about Russia
Authors: Debrenn Michèle
Published: April 2023

In this paper we examine how the communication of characters speaking different languages is reflected in French and Belgian graphic novels about Russia. We propose to distinguish the situation of bilingual (plurilingual) communication on one hand and the reflection of this situation on the other hand. We built different schemes in order to describe the character’s choice of the language of communication, taking into account the existence of a common language, the communicant’s level of proficiency in different languages, the environment. The choice of French (correct or not) or Russian (correct or not, Cyrillic or transliterated, translated or not) in the following modules of bilingual communication has been analyzed: 1) a speaker of Russian communicates with native speakers of French, 2) he communicates with other native speakers of Russian in a francophone environment, 3) he speaks to himself (or swears), 4) he communicates with native speakers of other languages, 5) a native speaker of French uses Russian languages in communication with native speakers of Russian. In francophone graphic novels, French language is used when English-speaking and Russian-speaking characters communicate. We analyze whether the text in Russian is correct or not, whether it is written in Cyrillic or Latin alphabet, the presence or absence of translation, its correctness, the means to reflect the accent or character’s poor knowledge of French language. In conclusion we propose to discuss the reasons for the common ignorance of language contact in graphic novels.