bluuebunny/crossref_metadata_2025 huggingface dataset:
The sustainability of exercise following colorectal surgery: A qualitative study of participants in the PREPARE-ABC trial
Authors: Naisby J , Baker K , Skarparis K , Murdoch J , Clark A , Stirling S , Turner D , Swart AM , Hernon J , Saxton J
Published: September 2024

Objective

This study aimed to explore perceptions regarding the sustainability of exercise following participation in a pre- and post-colorectal surgery exercise intervention trial (PREPARE-ABC).

Design

Qualitative interview study. Data were analysed using framework analysis and independently coded by two researchers.

Setting

Six United Kingdom National Health Service Trusts.

Participants

Eighteen interviews (hospital-based exercise n = 9, home-based exercise n = 3, standard care n = 6) were conducted with patients 12–15 months after being randomised in the trial, after their 12 month appointment.

Intervention

Individuals who participated in one of two exercise intervention groups (hospital-supervised or home-supported exercise) or a standard care control group of the PREPARE-ABC trial were invited to interview.

Results

The exercise interventions were reported to influence participants’ recovery and future sustainability of exercise behaviour change. Several participants continued to engage in exercise over a year after their surgery. Reasons for this included being engaged with exercise prior to diagnosis, psychological benefits of exercise and wanting to be engaged with something to help recovery. Perceptions about the sustainability of active lifestyles were influenced by confidence to engage in structured exercise or physical activity and beliefs about its potential to promote future wellness.

Conclusions

Sustainability varies among individuals and early assessment of physical activity engagement could be beneficial. Physical activity interventions immediately following surgery may be important for future engagement.
Adaptation and Validation of the Psychological Consequences of Screening Questionnaire (PCQ) for Cognitive Screening in Primary Care
Authors: Lovett Rebecca M. , Filec Sarah , Hurtado Jeimmy , Kwasny Mary , Sideman Alissa , Persell Stephen D. , Possin Katherine , Wolf Michael
Published: September 2024

Background

Context-specific measures with adequate external validity are needed to appropriately determine psychosocial effects related to screening for cognitive impairment.

Methods

Two-hundred adults aged ≥65 y recently completing routine, standardized cognitive screening as part of their Medicare annual wellness visit were administered an adapted version of the Psychological Consequences of Screening Questionnaire (PCQ), composed of negative (PCQ-Neg) and positive (PCQ-Pos) scales. Measure distribution, acceptability, internal consistency, factor structure, and external validity (construct, discriminative, criterion) were analyzed.

Results

Participants had a mean age of 73.3 y and were primarily female and socioeconomically advantaged. Most had a normal cognitive screening result (99.5%, n = 199). Overall PCQ scores were low (PCQ-Neg: [Formula: see text]= 1.27, possible range 0–36; PCQ-Pos: [Formula: see text] = 7.63, possible range 0–30). Both scales demonstrated floor effects. Acceptability was satisfactory, although the PCQ-Pos had slightly more item missingness. Both scales had Cronbach alphas >0.80 and a single-factor structure. Spearman correlations between the PCQ-Neg with general measures of psychological distress (Impacts of Events Scale–Revised, Perceived Stress Scale, Kessler Distress Scale) ranged from 0.26 to 0.37 ( P’s < 0.001); the correlation with the World Health Organization–Five Well-Being Index was −0.19 ( P < 0.01). The PCQ-Neg discriminated between those with and without a self-reported subjective cognitive complaint ([Formula: see text] = 2.73 v. 0.89, P < 0.001) and was associated with medical visit satisfaction ( r = −0.24, P < 0.001) on the Patient Satisfaction Questionnaire. The PCQ-Pos predicted self-reported willingness to engage in future screening ([Formula: see text] = 8.00 v. 3.00, P = 0.03).

Conclusions

The adapted PCQ-Neg is an overall valid measure of negative psychological consequences of cognitive screening; findings for the PCQ-Pos were more variable. Future studies should address measure performance among diverse samples and those with abnormal screening results.

Highlights

The PCQ scale is an overall valid measure of psychological dysfunction related to cognitive screening in older adults receiving normal screen results. PCQ scale performance should be further validated in diverse populations and those with abnormal cognitive screening results. The adapted PCQ may be useful to both health research and policy stakeholders seeking improved assessment of psychological impacts of cognitive screening.
A Transformative Orientation Model for Encouraging Responsible Marketing Actions
Authors: Scheinbaum Angeline Close , Steinfield Laurel , Giebelhausen Mike , Dobscha Susan
Published: September 2024

This set of studies tackles a timely, important, yet often overlooked component of marketing—encouraging marketing actors to engage in a socially just and responsible orientation to improve decision-making. We build on ethical, sustainable, social justice, and social marketing pedagogy by combining transformative learning theories with stakeholder recognition to provide a model that explains how marketers can develop a transformative orientation. With five studies, including three semester-long field experiments, one natural experiment/event study on Black Lives Matter Google searches, and a lab experiment, we present captivating empirical evidence that market actors can change their orientation to be more responsible and just. The model recognizes the importance of using a balanced frame of reference for marketing, and how this is mediated by metacognition activation and perspective gathering. This paper provides initial empirical evidence demonstrating how the way marketing materials are presented can improve the degree of transformation.
Continuum concentric push–pull robots: A Cosserat rod model
Authors: Tummers Matthias , Boyer Frédéric , Lebastard Vincent , Offermann Alexis , Troccaz Jocelyne , Rosa Benoît , Chikhaoui M. Taha
Published: September 2024

Various approaches and structures emerged recently to design continuum robots. One of the most promising designs regards a new concept of continuum concentric push–pull robots (CPPRs) that have the characteristic of combining several key advantages of tendon actuated, multi-backbone, and concentric tube ones (direct curvature actuation, small outer/inner diameter ratio, free lumen, etc.). Geometrically-exact models of such recently introduced robots are yet to be developed to gain leverage of their full potential. This article extends beyond usual definitions of Cosserat rod theory in order to take into account this new type of continuum robots, constituted by sliding rods, in a shape of tubes whose cross-sections are neither uniform nor symmetrical along their entire length. The introduced model is capable of considering versatile design options, external loads, 3D deformations, an arbitrary number of tubes and profiles of the centroid lines, as well as a new actuation method consisting of an input rotation. Numerical simulations and experiments on CPPR prototypes validate our model.
Nudging strategies to influence prescribers’ behavior toward reducing opioid prescriptions: a systematic scoping review
Authors: Diwan Salwan , Vilhelmsson Andreas , Wolf Axel , Jildenstål Pether
Published: September 2024

Objective

This systematic scoping review aimed to map the literature on the use of various nudging strategies to influence prescriber behavior toward reducing opioid prescriptions across diverse healthcare settings.

Methods

A systematic database search was conducted using seven electronic databases. Only articles published in English were included. A total of 2234 articles were identified, 35 of which met the inclusion criteria. Two independent dimensions were used to describe nudging strategies according to user action and the timing of their implementation.

Results

Six nudging strategies were identified. The most common strategy was default choices, followed by increasing salience of information or incentives and providing feedback. Moreover, 32 studies used the electronic health record as an implementation method, and 29 reported significant results. Most of the effective interventions were multicomponent interventions (i.e., combining nudge strategies and non-nudge components).

Conclusions

Most nudging strategies used a passive approach, such as defaulting prescriptions to generics and requiring no action from the prescriber. Although reported as effective, this approach often operates under the prescriber’s radar. Future research should explore the ethical implications of nudging strategies. INPLASY registration number: 202420082.
Preoperative frailty and postoperative complications after non-cardiac surgery: a systematic review
Authors: Becerra-Bolaños Ángel , Hernández-Aguiar Yanira , Rodríguez-Pérez Aurelio
Published: September 2024

Objective

Many tools have been used to assess frailty in the perioperative setting. However, no single scale has been shown to be the most effective in predicting postoperative complications. We evaluated the relationship between several frailty scales and the occurrence of complications following different non-cardiac surgeries.

Methods

This systematic review was registered in PROSPERO (CRD42023473401). The search strategy included PubMed, Google Scholar, and Embase, covering manuscripts published from January 2000 to July 2023. We included prospective and retrospective studies that evaluated frailty using specific scales and tracked patients postoperatively. Studies on cardiac, neurosurgical, and thoracic surgery were excluded because of the impact of underlying diseases on patients’ functional status. Narrative reviews, conference abstracts, and articles lacking a comprehensive definition of frailty were excluded.

Results

Of the 2204 articles identified, 145 were included in the review: 7 on non-cardiac surgery, 36 on general and digestive surgery, 19 on urology, 22 on vascular surgery, 36 on spinal surgery, and 25 on orthopedic/trauma surgery. The reviewed manuscripts confirmed that various frailty scales had been used to predict postoperative complications, mortality, and hospital stay across these surgical disciplines.

Conclusion

Despite differences among surgical populations, preoperative frailty assessment consistently predicts postoperative outcomes in non-cardiac surgeries.
Catalytic effect and kinetic mechanism of alkali metal carbonates on the reduction reaction of biochar with iron oxide
Authors: Han Chengjin , Wei Guangsheng , Wang Qisheng , Zhu Rong
Published: September 2024

Previous studies have shown that alkali metals catalyse the pyrolysis and gasification processes of biomass. However, whether alkali metals have the same catalytic effect on the reduction reaction of biochar with iron oxide has not been investigated. In this article, the effect of alkali metals on the reduction behaviour of biochar with iron oxide was investigated. It was shown that adding alkali metal carbonate could increase the reaction rate of CSC reduction stages 1 and 2, but it played an inhibitory role for the first and middle periods of stage 3. Moreover, adding alkali metals resulted in higher total CO2 gas production and reduced total CO gas production for the reduction reaction. The GB1 model was the best mechanistic model for stages 1 and 2 of the CSC-2K and CSC-2Na reduction reactions, while the C1 model was the best mechanistic model for stage 3.
Daily living skills in adolescents with and without (developmental) language disorder, measured using the WHEEL OF INDEPENDENCETM framework
Authors: Burridge Debbie , Hughes Lucy , Titterington Jill , Dawson Nicola , Ebbels Susan
Published: September 2024

Introduction:

Developing daily living skills, such as self-care, cooking and managing money, is a key priority for adolescents with special educational needs. Previous studies investigated the emergence of daily living skills in young people with a range of neurodevelopmental conditions. However, none focused on adolescents with language disorders, including developmental language disorder.

Method:

Two groups of 16-year-olds participated in this study: a typically developing group ( n = 88) and a (developmental) language disorder group ( n = 78), which was subdivided into participants with co-occurring motor difficulties ( n = 56) versus typical motor development ( n = 22). Data were collected using the WHEEL OF INDEPENDENCE™ framework, a daily living skills measurement tool. Between-group comparisons assessed whether there were significant differences in daily living skills between typically developing and (developmental) language disorder participants and between those with and without motor difficulties within the (developmental) language disorder group.

Results:

Findings revealed that typically developing participants had significantly better daily living skills than the (developmental) language disorder group. Within the (developmental) language disorder group, participants with motor difficulties showed marginally significantly lower daily living skills than those without.

Conclusion:

Adolescents with (developmental) language disorder experience challenges developing their daily living skills, compared to typically developing peers. This may be compounded if they have co-occurring motor difficulties. Further research could inform understanding of the mechanisms underlying these differences in order to develop tailored and effective interventions.
Impact of wind turbine nominal power limitation over wind turbine blade remaining useful life and its economic consequences
Authors: Chrétien Antoine , Tahan Antoine , Pelletier Francis
Published: September 2024

The present paper investigates the effects of wind turbine nominal power limitation on the remaining useful life of turbine blades. It also looks at the economic impact of this limitation. In this context, the paper provides wind turbine owners and operators with an overview of how to potentially extend the remaining useful life of wind turbine blades and lays out the economic benefits that can be achieved via the modulation of nominal power. In investigating wind turbine blade damage, prior studies focused mainly on predictive models based on the 10 minutes SCADA data wind speed history, without however, trying to protract the remaining useful life of the blades. Only a handful of papers have explored the possibility of increasing the remaining useful life by adjusting the start-up and shutdown procedures with poor results. It would appear that wind turbine blade fatigue damage mainly increases when the wind turbine is in a power production regime, and the mechanical stresses associated with this regime are a function of the nominal power of the wind turbine. The present work therefore investigates the impacts of nominal power changes on both the remaining useful life of wind turbine blades and the economic value of the wind turbine in a bid to identify an optimal control mode. The wind turbine blade damage evaluation is based on 10 minutes SCADA data and the FAST simulation tool with the ultimate goal of providing wind turbine operators with an easy application. The damage evaluation is then applied considering different nominal power levels for the same wind turbine model in order to see the resulting impact on the remaining useful life. This project therefore takes a pioneering approach by proposing a remaining useful life optimization tool to wind turbine operators, in effect, a decision-making tool regarding which exploitation strategy to adopt.
The impact of socio-demographic factors on web credibility assessment
Authors: Zeynali-Tazehkandi Mahdi , Nowkarizi Mohsen , Moradi-Biyarajmandi Zahra
Published: September 2024

The aim of this study is to investigate the relationship between web credibility evaluation and socio-demographic variables. A sample of 380 students from Ferdowsi University of Mashhad, Iran, was selected using stratified sampling methods. Data was collected through a questionnaire encompassing socio-demographic information and Choi items. The collected data was analysed using Spearman and Kruskal–Wallis non-parametric tests, guided by the data's characteristics (type and distribution). The findings reveal a significant association between interest, experience and academic level in determining web credibility assessments. Conversely, expertise, income, gender and age were not found to be influential factors. This is a first attempt to determine the impact of socio-demographic variables on web credibility assessment. The findings suggest that individuals from diverse age, gender and income groups could benefit from acquiring knowledge pertaining to web credibility and engaging in workshops related to this domain. Additionally, those with lower levels of experience, education and interest may derive greater value from participating in web-credibility-evaluation workshops.
The intratesticular artery resistive index as a predictor of spermatogenesis: A prospective study
Authors: Sharma Sachin , Yash Manharlal Tilala , Tripathi Abhilekh , Swain Samir , Panda Sabyasachi , Paul Amiya Shankar , Choudhuri Sanjay
Published: September 2024

Introduction:

With the objective to assess the correlation between the resistive index of intratesticular artery as predictor of spermatogenesis this case control study was conducted.

Methods:

A Prospective study conducted during period April 2021 to March 2023. Total 50 patients, with oligoasthenozoospermia taken as cases and other 50 men with normal sperm count taken as controls. History taken & clinical examination, Semen analysis, hormonal evaluation & Color Doppler ultrasonography of scrotum done. Resistive Index of testicular arteries was obtained. Cases and controls were compared.

Results:

The age of the study group ranged between 21 and 40 years. Among the cases maximum patients 23 out of 50 and among controls with maximum number 21 out of 50 patients were belonged to age group 26–30 years.The mean semen volume for the cases & controls was 2.76 ± 0.44 ml and 3.32 ± 0.54 ml respectively. The Mean sperm concentration in the cases & controls was 14.33 million/ml & 84.8 million/ml. Mean Type A sperm motility was 20.82% ± 7.86 in cases and 54.96% ± 5.41 in controls. The mean testicular volume in cases was 18.36 ± 0.75 & in controls was 18.39 ± 0.62 ml. Hormonal evaluation done in both cases and controls and mean value of FSH in cases and controls was 7.57 ± 2.34 and 6.27 ± 3.55 respectively ( p-value = 0.036). Mean value of Resistive Index (PSV − EDV)/PSV) in cases and controls were found 0.63 ± 0.32 and 0.53 ± 0.37 respectively ( p-value = 0.001).

Conclusion:

The intratesticular artery resistive index can be utilized as valuable predictive marker to indicate spermatogenesis.
Acoustic emission-based delamination investigation in drilled GFRP under mixed tensile and bending cyclic loading
Authors: Beigi Amirhossein , Bastani Lay Ali , Ahmadi Najafabadi Mehdi
Published: September 2024

The drilling process can cause various defects in glass fiber-reinforced polymer (GFRP), such as delamination, which ultimately leads to damage progression, especially under fatigue loading. Therefore, the current study aims to investigate the progression of failure in drilled composites subjected to cyclic bending and tensile loads using acoustic emission (AE), image processing, and mechanical behavior monitoring. The results show tyhat the fatigue diagram consists of three stages associated with resistance of fibers and matrix against delamination propagation, stable delamination progression, and ultimate spread of failure which are accurately identified by AE and mechanical methods. Additionally, the pattern and procedure of all fatigue diagrams under all loading conditions were similar and independent of loading parameters. Results from this study provide a strategy for real-time structural health monitoring (SHM) of delamination propagation in GFRPs under multi-axial fatigue loading.
Development and validation of Social Support Needs Questionnaire (SSNQ) for the left-behind older adults in rural China
Authors: Zhang Tongyu , Kang Yanan , Liang Qi , Zhang Siai , Wei Wentong , Zhang Chunmei , Yang Xueshi , Wang Ruirui , Yang Ting , Yang Huifeng
Published: September 2024

Objectives: This study compiled a Social Support Needs Questionnaire (SSNQ) for the left-behind older adults in rural China and assessed its psychometric properties. Methods: The formation of the SSNQ included three stages. First, item pool was established based on literature analysis. Second, through expert consultation, the 1-version questionnaire items were determined. Third, pre-survey with 901 cases of rural left-behind older adults was used to develop and test final-version of the Social Support Needs Questionnaire (SSNQ). Results: The Cronbach’s α of the SSNQ was 0.914, ranging from 0.815 to 0.886 for each factor. The item-content validity index ranged from 0.875 to 1.00, and the scale-content validity index was 0.969. Conclusions: The SSNQ prepared by this study can be used as an evaluation tool for the social support needs of left-behind older adults in rural China, providing a basis for further establishment of the social support system.
Informing Culturally Safe Advance Care Planning: An Interpretive Descriptive Study of Internationally Educated Nurses in Ontario
Authors: Jonathan Shereen , Pfaff Kathryn , Cruz Edward
Published: September 2024

Background

Maintaining cultural safety during advance care planning (ACP) discussions is an essential component of holistic care provision. Most nurses feel unprepared to engage in ACP and the current literature offers limited recommendations on how nurses can lead culturally safe ACP discussions. Internationally educated nurses (IENs) have unique personal and professional experiences to address this gap.

Purpose

The purpose of this study was to understand IENs’ contributions to culturally safe ACP and its implications to nursing practice and ACP policy.

Methods

An interpretive descriptive approach was undertaken. Ten IENs working in Ontario, Canada were individually interviewed using a semi-structured guide to understand their perspectives and experiences of engagement in culturally safe ACP practices.

Results

IENs utilized various approaches that were reflected in three actions: practicing cultural humility, utilizing a cautious approach, and empowering clients and families. IENs engaged in intrapersonal and interpersonal cultural humility practices to recognize the unique influence of one's culture on the ACP process. Establishing trust in the nurse-client relationship and cautiously approaching ACP conversations was recognized as important in maintaining cultural safety. IENs also empowered clients by addressing knowledge deficits, misconceptions about ACP, and informing them of their decision-making rights.

Conclusion

Nurses require education and resources to carry out culturally safe ACP. Education should begin at the undergraduate level and include self-engagement in ACP and cultural humility training. Practicing nurses need ACP training and clear standards/guidelines. There is an opportunity for healthcare organizations and professional/governing nursing bodies to collaborate on developing culturally safe ACP guidelines.
Using a Previsit Questionnaire for Initial Visits in a Pediatric Mitochondrial Clinic: Perspectives of Parents, a Specialty Physician, and a Clinical Coordinator
Authors: Sepulveda Coral J. , Walsh Elaine , Carlin Kristen , Saneto Russell P.
Published: September 2024

Objective: In this study, we assessed the usefulness of a previsit questionnaire for children who were referred for an initial evaluation in a mitochondrial subspecialty clinic. We explored the themes regarding parent's questions, concerns, and goals. We aimed to add to existing knowledge about the usefulness of previsit questionnaires in a pediatric specialty setting from the perspective of parents, the specialist, and the clinical coordinator. Method: We enrolled 25 patients and their parent(s) over 25 months. Questionnaires were completed by the parent(s), the clinical coordinator, and the mitochondrial specialist. Descriptive statistics and thematic analysis were used to summarize results. Results: Parental responses suggested that they are most concerned about their child's clinical problems, communication, language and developmental delays, disease progression and prognosis, understanding mitochondrial disease, quality of life, and physical challenges including muscle and energy problems. Parents felt the previsit questionnaire was very helpful for both the doctor and for themselves to be prepared for their visit. The specialist and the clinical coordinator also found it to be helpful. Parental comments suggested that they felt that writing down the story of their child's life was helpful for the provider, allowed time for reflection, and improved the appointment experience. Some felt it was a difficult or redundant activity. Conclusion: Parents were often pleased to complete the previsit questionnaire. This allowed them to highlight concerns and share information that they wanted the care team to know about their child. We revised the tool based on feedback from parents and the specialist and will continue to use it in our clinic.
N-acetyl-cysteine in Intensive Care Unit Patients with Acute Respiratory Distress Syndrome due to COVID-19: A Retrospective Cohort Study
Authors: González-Guzmán Diego , Andrade-Castellanos Carlos A. , Ponce-Gallegos Marco A. , Mesina-Estarrón Ignacio , Mora-Almanza José G. , Ruelas-Moreno Hugo E. , Rodríguez-González Daniel , Eguia-Ortega Omar , Colunga-Lozano Luis Enrique
Published: September 2024

COVID-19-related acute respiratory distress syndrome (ARDS) is linked to mortality, primarily due to a cytokine storm, oxidative stress imbalance, and pro-thrombotic state.

Purpose

We assessed the potential association between N-acetyl-cysteine (NAC) and clinical outcomes in critically ill subjects with COVID-19-related ARDS.

Material and Methods

We included subjects with confirmed COVID-19 who were admitted to our ICU between March 1, 2020, and January 31, 2021, due to ARDS and necessitating invasive mechanical ventilation (IMV). Subjects who received standard of care (SOC) were compared with subjects who additionally received NAC 600 mg bid orally.

Results

A total of 243 subjects were included in this study. The results indicate significantly improved survival rates in the NAC plus SOC group, both in the unadjusted analysis and after adjusting for confounding factors such as ARDS severity (HR 0.48, 95% CI 0.32-0.70).

Conclusions

We found that oral administration of NAC was associated with reduced mortality in critically ill patients with COVID-19 related ARDS.
Children’s Educational Attainment and Older Parents’ Food Insecurity: Evidence From India
Authors: Mustafa Akif , Shekhar Chander
Published: September 2024

Objectives: To examine the relationship between children’s educational attainment and the risk of food insecurity among older parents and to determine if this relationship varies by the sex and residence of the children. Methods: This study utilized data from the Longitudinal Ageing Survey in India (LASI, 2017-18), comprising 25,914 individuals aged 60+ with at least one living child. Logistic regression, interaction analysis, and propensity score matching were employed to achieve the study’s objectives. Results: Having a child with higher education (undergraduate or above) was associated with a 35% reduction in the odds of parents experiencing food insecurity. This negative relationship was significant for both sons’ and daughters’ education, with daughters’ education having higher effect size. Conclusion: In a country like India, characterized by a weak welfare system but a strong collectivist family culture, children’s education may play an important role in ensuring older parents’ food security.
Quantifying theory in politics: Identification, interpretation, and the role of structural methods
Authors: Canen Nathan , Ramsay Kristopher
Published: September 2024

The best empirical research in political science clearly defines substantive parameters of interest, presents a set of assumptions that guarantees their identification, and uses an appropriate estimator. We argue for the importance of explicitly integrating rigorous theory into this process and focus on the advantages of doing so. By integrating a theoretical structure into one’s empirical strategy, researchers can quantify the effects of competing mechanisms, consider the ex-ante effects of new policies, extrapolate findings to new environments, estimate model-specific theoretical parameters, evaluate the fit of a theoretical model, and test competing models that aim to explain the same phenomena. As a guide to such a methodology, we provide an overview of structural estimation, including formal definitions, implementation suggestions, examples, and comparisons to other methods.
The fabrication of polyimide-based tunable ternary memristors doped with Ni-Co coated carbon composite nanofibers
Authors: Liu Yuanyuan , Zhao He , Liu Liyuan , Yin Jinghua
Published: September 2024

Polymer matrix composite memristors exhibit exceptional performances, including a straightforward structure, rapid operational speed, high density, good scalability, cost-effectiveness, and superior mechanical flexibility for wearable applications. This study utilizes sensitized chemical evaporation and spin coating carbonization techniques to fabricate composite nanofibers doped with Nickel-Cobalt coated multi-walled carbon nanotubes (SC-NCMTs). A novel polyimide matrix composite memory device was fabricated using in-situ polymerization technology. The transmission electron microscopy (TEM) and micro-Raman spectroscopy analyses validate the presence of dual interfaces structure locating between the Ni-Co-MWNTs, carbon nanofibers and PI matrix and a large number of defects in the SC-NCMTs/PI composite films, resulting in tunable ternary resistive switching behaviors of the composite memory device, exhibiting good ON/OFF current ratio of 104 and a retention time of 2500 s under operating voltages Vonset ≤ 3 V. Based on the interface layer distribution and the defects in the composites, different physical models are comprised to investigate the charge transmission mechanism underlying the multilevel resistive switching behaviors. The studies on the impact of tunable multi-interfaces trap structures on multilevel resistive switching could enhance the data storage capabilities of polymer matrix memristors.
Dynamic flexible job shop scheduling based on deep reinforcement learning
Authors: Yang Dan , Shu Xiantao , Yu Zhen , Lu Guangtao , Ji Songlin , Wang Jiabing , He Kongde
Published: September 2024

The unpredictable dynamic events in smart factory seriously influence the scheduling schemes and production efficiency. To minimize the total tardiness of orders, this paper proposes a Deep Reinforcement Learning (DRL) method to solve the Dynamic Flexible Job Shop Scheduling Problem (DFJSP) with random job arrival. In the scheduling process, the intelligent agent can select the operations to be processed on the available machines according to the job shop state at each scheduling point by transforming DFJSP into a Markov Decision Process (MDP). For reflecting the job shop environment, eight state features are extracted, and six composite dispatching rules are designed as the action space. Moreover, a reward function is developed to enhance the learning efficiency and solution quality of the intelligent agent, the Soft-max selection strategy is applied to balance exploration and exploitation. The Dueling Double Deep Q-Network (Dueling DDQN) algorithm is introduced to train the intelligent agent, which effectively alleviates the overestimation problem. Numerical simulation results show that the proposed Dueling DDQN method effectively solves the DFJSP. Compared with existing scheduling strategies, the proposed approach not only exhibits superior performance but also maintains its advantages among different scale instances.
A probabilistic prediction model based on stacking ensemble learning for completion time in flexible shop-floor
Authors: Chang Xiao , Jia Xiaoliang , Fan Chen
Published: September 2024

Completion time prediction is crucial for analyzing and monitoring the execution of shop-floor’s production planning. However, predicting completion time is still challenging because production process has high uncertainty and influenced by the interaction of various factors. To address above challenges, the stacking ensemble learning based probabilistic prediction model (SEL-PP) to predict completion time is developed. Thereinto, fully connected neural network (FCNN), random forest (RF) and gradient boosted regression tree (GBRT) are used as the first-level base learner to exhibit better nonlinear characteristics, and quantile regression neural network (QRNN) is used as the second-level meta-learner to rectify the mistakes in the prediction of the base learner. After that, the kernel density estimation (KDE) is employed for achieving probability density prediction of completion time. Moreover, particle swarm optimization (PSO) is adopted for key parameter optimization of SEL-PP. Taking the aircraft overhaul shop-floor as an example, a case study is constructed to demonstrate the feasibility and effectiveness of SEL-PP. Through comparing the results, it indicates that the SEL-PP model has better performance in predicting completion time of flexible shop-floor.
Kinematic and aerodynamic analysis of a Microraptor-inspired foldable wing mechanism
Authors: Shahid Farzeen , Kilian Lukas , Jingshan-Zhao
Published: September 2024

Bio-inspired mechanisms have opened new avenues of research to understand the flying capabilities of birds. While extensive studies have explored the aerodynamics and kinematics of bird flapping motions, limited attention has been given to the folding motion. This paper introduces a foldable wing mechanism inspired by avian anatomy, specifically drawing inspiration from Microraptor aerodynamics. Employing the screw theory approach, we analyze the kinematics of the mechanism and conduct parametric calculations. By segmenting the mechanism and integrating the solutions, we develop an algorithm that demonstrates favorable power transmission, enabling the wing to remain extended with minimal actuation forces. We further employ position analysis to investigate the system’s functionality analytically. To optimize the mechanism, we utilize the gradient descent method. We validate the achieved momentum and velocities through an illustrative example by solving individual four-bar segments and transmitting the outputs to adjacent segments. The study utilizes detailed 3D modeling techniques employing SolidWorks software to accurately represent the wing designs. The results obtained provide valuable insights into the aerodynamic behavior of Microraptor, by comparing the coefficients of lift and drag in graphical form and contribute to the advancement of micro-aerial vehicle design.
Research on time delay compensation control of Taylor series backstepping for magnetorheological semi-active suspension
Authors: Long Jiangqi , Kong Zhe , Zhang Jianhong
Published: September 2024

The investigation of magnetorheological (MR) semi-active suspension is crucial for automotive applications. This paper introduces a novel approach by considering time delay effect when load changes and considering vehicle’s spring-loaded mass as an uncertain parameter. To address these challenges, a new magnetorheological semi-active quarter-vehicle suspension controller is proposed. Controller combines inverse model with Taylor series backstepping control strategy to determine the necessary damping force provided by magnetorheological damper based on system’s dynamic error. Additionally, damping force is compensated using Taylor series expansion method. Drive current of magnetorheological damper is obtained by solving hyperbolic positive model parameters and inverse model through nonlinear least squares genetic algorithm. Simulation experiments are conducted to compare the performance of Taylor series backstepping control (TBS) suspension, backstepping control suspension affected by time delay, MSH control suspension affected by time delay and passive suspension. Various metrics such as spring-loaded mass displacement, velocity, acceleration, suspension dynamic displacement, and wheel dynamic load under random road excitation are evaluated. Simulation results demonstrate that proposed system effectively mitigates vehicle vibration caused by time delay and load variations, while enhancing vehicle’s handling and smoothness.
Operational transfer path analysis for the fixed shaft gear transmission system based on the simulation and experiment
Authors: Liu Hui , Yan Qi , Gao Pu , Yan Keyu , Xie Yunkun
Published: September 2024

The Operational Transfer Path Analysis (OTPA) is widely used to analyze signal transfer paths in various fields, but its applications in gear transmission systems are limited. In this paper, the OTPA method is appropriately applied to the study of vibration signal transfer paths of fixed shaft gear transmission systems. Firstly, the dynamic model of a three-axis two-stage fixed-shaft gear transmission system is developed. This model takes into account factors such as the impact of dynamic center distance on backlash and provides a comprehensive analysis of time-varying meshing stiffness and forces. Experiments are conducted to verify the accuracy of the model. Subsequently, this paper delves into the OTPA process for solving the signal transfer coefficient matrix. It also derives the calculation method for computing the contribution of signal transfer paths, which provides a theoretical basis for establishing the evaluation mechanism of the signal transfer paths. Next, the gear transmission system’s signal transfer is analyzed based on the OTPA method, and the contribution of each path is computed. The dominant path is identified by ranking the contribution of these paths. Finally, the excitation experiment of a single signal transfer path reveals the essence of the signal transfer mechanism. This research contributes to a deeper understanding of signal transfer paths within gear transmission systems based on the OTPA method, it identifies the optimal distribution of sensor installation positions for fault signal diagnosis, paving the way for more effective fault detection and diagnosis in the gear transmission system.
Investigations on laser-assisted turning of IN625 alloy with hot hardness approach using uncoated and CrAlSiN coated WC tools
Authors: Rao Amarendhar , Tak Manish , Rao Narasimha , Vallleti Krishna , Bathe Ravi
Published: September 2024

This paper presents an investigation into the effect of laser-assisted turning of the IN625 superalloy using uncoated and CrAlSiN nanocomposite-coated tungsten carbide tools. A hot hardness test was conducted for IN625 material, which showed there was a pronounced softening of the material above 850 °C. This exercise guided the choice of laser power for the subsequent laser-assisted turning experiments. The cutting forces (radial/thrust, Fx; axial/feed, Fy; and tangential/cutting, Fz), maximum flank wear (VBBmax), and surface roughness ( Ra) were measured and analyzed for the planned experiments. The results demonstrated that at 2500 W laser power, a 9%, 70%, and 59% reduction of cutting forces for uncoated tools, and a 31%, 77%, and 69% reduction for CrAlSiN coated tools were observed in the Fx, Fy, and Fz directions respectively. At 2250 W laser power, the uncoated tools exhibited a 33% (433–289 µm) reduction in VBBmax and a 28% (1.8–1.3 µm) reduction in Ra. The CrAlSiN-coated tools, at 2500 W laser power, showed even more significant improvements, with reductions of 46% (365–232 µm) in VBBmax and 56% (1.4–0.8 µm) in Ra. The results underline the improved performance of laser-assisted turning for cutting-force and tool-wear reduction and improved surface finish with CrAlSiN-coated tools. This paper presents the potential of laser-assisted machining as a viable method for machining difficult-to-machine materials like IN625, which offers enormous manufacturing productivity and tool life benefits.
A comparative study based on ainuovirine/lamivudine/tenofovir against HIV-1
Authors: Luo Peipei , Jin Juan , Li Jiajia , Yin Jinling , Jing Xinyan , Hou Haohua , Ba Huanhuan , Zhang Yuan
Published: September 2024

Background

Ainuovirine, as a third-generation non-nucleoside reverse transcriptase inhibitor against HIV-1, is widely used in China. To evaluate its therapeutic efficacy and disadvantages, a comparative study based on Ainuovirine had been conducted.

Method

We investigated 199 people living with HIV-1 who received Ainuovirine (ANV)/lamivudine/tenofovir and 202 people living with HIV-1 who received Efavirenz (EFV)/lamivudine/tenofovir.

Results

After 48 weeks of therapy, ANV and EFV showed similar viral inhibitory effects. However, in the ANV group, more participants had CD4/CD8 ratios restored to the normal range, lower levels of triglycerides and low-density lipoprotein, relatively normal liver alanine aminotransferase, and fewer adverse events.

Conclusion

Therefore, due to its role in immune reconstitution, dyslipidemia, and safety, ANV may be a recommended option for people living with HIV-1.
Analysis of the aerothermal performance of modern commercial high-pressure turbine rotors using different levels of fidelity
Authors: Carta Mario , Shahpar Shahrokh , Ghisu Tiziano
Published: September 2024

In the field of design and optimization of sophisticated geometries such as film-cooled turbine blades of modern jet engines, Computational Fluid Dynamics (CFD) simulation is commonly employed. As the pursuit for higher turbine entry temperatures intensifies, it becomes crucial for computational analyses to offer accurate predictions of metal temperatures and heat transfer coefficients on these critical components. This study investigates the impact of key physical factors that characterize the operation of these components on the accuracy of the computational model. In particular, the effects of including the exchange of thermal energy between the fluid and solid domains, as well as modelling the unsteady interaction between the rotor and stator are studied. The research focuses on a fully featured one-and-a-half stage high-pressure turbine of a commercial jet engine, utilizing proprietary software for conducting 3D Reynolds-Averaged Navier-Stokes flow simulations. To model the fluid-solid thermal interaction, steady-state Conjugate Heat Transfer (CHT) simulations are performed. The CHT results are then compared with experimental data obtained from a thermal paint test, achieving good levels of agreement. Additionally, phase-lag simulations are executed under adiabatic-wall conditions to evaluate the influence of stator-rotor interaction on near-wall gas temperatures. This work shows that, by modelling the periodic unsteadiness at the stator-rotor interface with a phase-lag technique, the maximum near-wall gas temperature prediction is significantly increased, sometimes more than 100K, with respect to the steady-state model one. Findings from this work also suggest that simplified “strip” source terms used to model the presence of film cooling hole rows on the surface of a blade can be used with satisfactory accuracy only for nominal conditions. The mass flows delivered by each source strip should not be linearly scaled based on mainstream quantities for use in different conditions, but they should be recalculated from scratch for the new conditions.
Optimized heterogeneous bi-directional recurrent neural network for early leaf disease detection and pesticides recommendation system
Authors: Madhu Sailaja , Ravi Sankar V
Published: September 2024

In this manuscript, optimized heterogeneous bi-directional recurrent neural network for early leaf disease detection and pesticides recommendation system (HBDRNN-ELD-PRS) is proposed. Initially, the input images are collected from plant dataset. To execute this, the collected input image is pre-processed using multimodal hierarchical graph collaborative filtering (MHGCF) for removing the noise, then the pre-processed images are fed to the feature extraction using second-order synchrony-extracting wavelet transform (SOSEWT) to extract the geometric features, such as area, slope, cancroids and perimeter. Then the extracted images are fed to the heterogeneous bi-directional recurrent neural network (HBDRNN) for effectively categorize Leaf Disease Detection as pepper bell bacterial spot, pepper bell healthy, potato late blight, potato early blight, potato healthy. Generally, HBDRNN does not adapt any optimization methods to compute optimal parameters to ensure accurate leaf diseases classification. Hence, the harbor seal whiskers optimization algorithm (HSWOA) is proposed to optimize the heterogeneous bi-directional recurrent neural network which accurately classifies the leaf disease. The proposed HBDRNN-ELD-PRS is implemented in Python. The performance metrics, such as accuracy, precision, specificity, recall, F1-score, computation time, ROC are analyzed. The proposed HBDRNN-ELD-PRS approach achieves 99.87% accuracy, 98.09% precision, and 97.83% recall when compared to the existing techniques.
Design optimization and simulation of a 3D printed cable-driven continuum robot using IKM-ANN and nTop software
Authors: Djeffal Selman , Ghoul Abdelhamid , Saadi Abdelhakim , Izri Zineddine , Morakchi Mohamed Razi , Wang Hoa
Published: September 2024

The first aspect of the paper focuses on presenting the innovative design of a new continuum robot, which was initially conceptualized using SolidWorks and then brought to life through 3D printing. This section illustrates the construction process, detailing the wiring method and the separator between each section of the robot. A key feature of the newly proposed design is the ball-like shape on the upper side of each disk, allowing each disk to rotate freely and gracefully in conjunction with the next one. To further enhance the design, the disk was optimized using nTopology software, an AI-based solution that reduces weight while maintaining performance. This modern engineering tool proved to be instrumental in addressing engineering challenges effectively. Subsequently, both the original and optimized disks were fabricated using 3D printing technology. In addition to the physical construction, the study employed an Artificial Neural Network (ANN) coupled with Particle Swarm Optimization (PSO) to simulate the developed model by solving its inverse kinematic model. The findings from this research have paved the way for a new continuum robot design that can be trained using the ANN-PSO method. Furthermore, the powerful nTopology tool was demonstrated to be capable of skillfully optimizing any given components without sacrificing performance.