bluuebunny/crossref_metadata_2025 huggingface dataset:
Machine Learning Methods to Estimate Individualized Treatment Effects for Use in Health Technology Assessment
Authors: Zhang Yingying , Kreif Noemi , GC Vijay S. , Manca Andrea
Published: July 2024

Background

Recent developments in causal inference and machine learning (ML) allow for the estimation of individualized treatment effects (ITEs), which reveal whether treatment effectiveness varies according to patients’ observed covariates. ITEs can be used to stratify health policy decisions according to individual characteristics and potentially achieve greater population health. Little is known about the appropriateness of available ML methods for use in health technology assessment.

Methods

In this scoping review, we evaluate ML methods available for estimating ITEs, aiming to help practitioners assess their suitability in health technology assessment. We present a taxonomy of ML approaches, categorized by key challenges in health technology assessment using observational data, including handling time-varying confounding and time-to event data and quantifying uncertainty.

Results

We found a wide range of algorithms for simpler settings with baseline confounding and continuous or binary outcomes. Not many ML algorithms can handle time-varying or unobserved confounding, and at the time of writing, no ML algorithm was capable of estimating ITEs for time-to-event outcomes while accounting for time-varying confounding. Many of the ML algorithms that estimate ITEs in longitudinal settings do not formally quantify uncertainty around the point estimates.

Limitations

This scoping review may not cover all relevant ML methods and algorithms as they are continuously evolving.

Conclusions

Existing ML methods available for ITE estimation are limited in handling important challenges posed by observational data when used for cost-effectiveness analysis, such as time-to-event outcomes, time-varying and hidden confounding, or the need to estimate sampling uncertainty around the estimates.

Implications

ML methods are promising but need further development before they can be used to estimate ITEs for health technology assessments.

Highlights

Estimating individualized treatment effects (ITEs) using observational data and machine learning (ML) can support personalized treatment advice and help deliver more customized information on the effectiveness and cost-effectiveness of health technologies. ML methods for ITE estimation are mostly designed for handling confounding at baseline but not time-varying or unobserved confounding. The few models that account for time-varying confounding are designed for continuous or binary outcomes, not time-to-event outcomes. Not all ML methods for estimating ITEs can quantify the uncertainty of their predictions. Future work on developing ML that addresses the concerns summarized in this review is needed before these methods can be widely used in clinical and health technology assessment–like decision making.
Constructing Limited-Revisable and Stable CPPIs for Small Domains
Authors: Ishaak Farley , Ouwehand Pim , Remoy Hilde
Published: July 2024

Constructing price indices for commercial real estate (CPPIs) is challenging due to heterogeneous and limited observations. Common price index methods often result in volatile index series. Attempts to reduce volatility often lead to frequent revisions of the entire index series and a loss of methodological index properties. When it comes to CPPIs in official statistics, both volatility and frequent revisions are undesirable. Revisions could compromise the confidence of users if indicators are allowed to change indefinitely, while instable indices insufficiently reflect structural underlying developments. In this study, a combination of hedonic imputation, multilateral calculations, time series analysis, and window splicing is introduced. The result is a method that produces stable and limited-revisable indices with the ability to detect turning points in an early stage. Commercial real estate transactions in the Netherlands are used to empirically test the method. The resulting CPPIs appear suitable for monitoring financial stability and, therefore, seem appropriate for the use in official statistics.
Eliminating eccentricity error in measuring residual stresses via hole-drilling method using strain gauge rosette with five measuring grids: For thin plates using through-holes
Authors: Gu Ying , Chen Jiaojiao , Gu Song , Kong Chao , Ren Songbo , Du Yixiang
Published: July 2024

In the measurement of residual stresses (RSs) via the hole-drilling method, the error induced by the eccentricity of the drilled hole is inevitable and non-negligible in some cases. In this study, both the eccentricity coordinates and RS state (two principal stresses and one principal angle) are considered unknowns that must be solved. A set of five equations is required to determine these five unknowns. Therefore, two additional measuring grids are added to the strain gauge comprising three grids, which is typically used in measuring RSs. Consequently, a novel strain gauge rosette with five measuring grids (SGR-5MG) is created. Subsequently, an algorithm associated with the SGR-5MG is developed to solve the five unknowns based on the Newton–Raphson method. The algorithm is elasticity-based and derived according to the layout of the SGR-5MG. Finally, the proposed method is verified numerically and experimentally. The results show that (1) the eccentricity error is up to 35.1% when the eccentricity reaches 0.05 D, where D represents the diameter of the gauge circle; (2) Using the proposed method, the error can be significantly reduced to 7.2%; (3) The elasticity-based proposed method cannot make the predicted results exactly converge to the actual stresses in predicting high stresses because of the plasticity deformation around the hole. The eccentricity error can be reduced significantly by using the proposed method based on the SGR-5MG.
Unsettled Times: The Contestation and Reproduction of Flexible Scheduling in Pandemic-Era Restaurant Work
Authors: Protasiuk Ewa
Published: July 2024

Flexible capitalism fosters the organization of worker time around demand, with challenging consequences for precarious and low-wage workers. I examine how this paradigm of work time fared in a context of economic and social disruption, namely the COVID-19 pandemic. Drawing on a qualitative study of restaurant work in the U.S., I argue that shifts in power over work time interacted with the moral and relational nature of time, resulting in both contestation and continuity of the flexible time paradigm. This paper has implications for understanding factors shaping change and stability in flexibly organized and precarious work.
Setting Regional Priorities for Palliative and End-of-Life Care Research Using a Delphi Technique Approach
Authors: Efstathiou Nikolaos , Guo Ping , Walker Wendy , MacArtney John I. , Bailey Cara
Published: July 2024

Objective

Identifying research priorities is very important for palliative and end-of-life care to ensure research is focused on evidence gaps. This project aimed to identify and prioritise palliative and end-of-life care research areas within the West Midlands region in United Kingdom (UK).

Methods

A modified Delphi technique approach was used with palliative care stakeholders. The first round was item generation via rapid interviews. Data were analysed using content analysis and all the items were grouped into main categories. For round two, an online survey was conducted to present all the items from round one, and stakeholders were asked to rate the priority of items on a Likert-type scale (1 = not a priority to 7 = essential priority). Items that achieved consensus in round two were presented to the third round, where stakeholders ranked them in descending order.

Results

We completed and analysed 56 rapid interviews which resulted in 158 research items under 15 categories. The research items were rated by 30 stakeholders and seven items which reached consensus were subsequently ranked in order by 45 stakeholders. The highest ranked item was ‘Integrated care systems to prevent crisis’, followed by three research items related to ‘equity’ in palliative care.

Conclusions

Our research priorities, although unique for our region, mirror previously research priorities from other regions and countries. This suggests issues of integration and equity in palliative and end-of-life care remain unresolved, despite ongoing initiatives and research to address these issues.
Nurses Navigating Mental Health During Uncharted Times: Self, Others, Systems (S.O.S)!
Authors: Akoo Chaman , Price Sheri , McMillan Kimberly , Ingraham Kenchera , Ayoub Abby , Rolle Sands Shamel , Shankland Mylène , Bourgeault Ivy
Published: July 2024

Study Background

The nursing profession is facing a multiplicity of stressors that have both predated and been exacerbated by the Covid-19 pandemic. The emotional and physical demands entailed in nursing predispose nurses to suboptimal mental health and burnout.

Purpose

This paper draws upon the narrative interviews of 53 Canadian nurses as part of a larger pan-Canadian, cross disciplinary study that examined the gendered experiences of mental health, leaves of absence, and return to work of 7 professions.

Methods

Thorne's interpretive descriptive guided Iterative and thematic analysis which identified three predominant themes within the nursing dataset, this paper focuses on the substantive theme of ‘ Navigating it Alone,’

Results

Nurses expressed a profound sense of isolation at 3 particular levels: at home, at work, and in systems – while simultaneously balancing uniquely gendered familial responsibilities and workplace demands.

Conclusions

These results illuminate instrumental pathways for stakeholders to attenuate the personal and professional pressures that continue to be disproportionately carried by nurses as they navigate these particularly challenging times.
Developmental Curves of the Paediatric Brain Using FLAIR MRI Texture Biomarkers
Authors: Chan Karissa , Rabba Dania , Vidarsson Logi , Wagner Matthias W. , Ertl-Wagner Birgit B. , Khademi April
Published: July 2024

Purpose: Analysis of FLAIR MRI sequences is gaining momentum in brain maturation studies, and this study aimed to establish normative developmental curves for FLAIR texture biomarkers in the paediatric brain. Methods: A retrospective, single-centre dataset of 465/512 healthy paediatric FLAIR volumes was used, with one pathological volume for proof-of-concept. Participants were included if the MRI was unremarkable as determined by a neuroradiologist. An automated intensity normalization algorithm was used to standardize FLAIR signal intensity across MRI scanners and individuals. FLAIR texture biomarkers were extracted from grey matter (GM), white matter (WM), deep GM, and cortical GM regions. Sex-specific percentile curves were reported and modelled for each tissue type. Correlations between texture and established biomarkers including intensity volume were examined. Biomarkers from the pathological volume were extracted to demonstrate clinical utility of normative curves. Results: This study analyzed 465 FLAIR sequences in children and adolescents (mean age 10.65 ± 4.22 years, range 2-19 years, 220 males, 245 females). In the WM, texture increased to a maximum at around 8 to 10 years, with different trends between females and males in adolescence. In the GM, texture increased over the age range while demonstrating a local maximum at 8 to 10 years. Texture had an inverse relationship with intensity in the WM across all ages. WM and edema in a pathological brain exhibited abnormal texture values outside of the normative growth curves. Conclusion: Normative curves for texture biomarkers in FLAIR sequences may be used to assess brain maturation and microstructural changes over the paediatric age range.
Copper ion-doped multifunctional hydrogel with mild photothermal enhancement promotes vascularized bone regeneration
Authors: Han Chao , Lu Dingsong , Yang Suoping , Liu Chong , Guo Feng , Zhang Kai , Li Peng
Published: July 2024

The design and construction of a new and excellent synthetic graft is of great significance in the field of bone defect repair and reconstruction. In this study, a dopamine modified chitosan hydrogel doped with Cu ions with a mild photothermal effect was designed to provide a better microenvironment to advance the bone repair via promote the angiogenesis and osteogenesis. Characterizations showed the successful synthesis of the material while it also presented excellent biocompatibility and mild photothermal effect under the irradiation of near-infrared light. Further, it could enhance the angiogenesis of HUVECs cells through promoting the ability of migration and tube formation and enhance the osteogenic differentiation of MC3T3-E1 cells via increasing the content of vital osteogenic factors including Runx2, Col-1, OPN, OCN, OSX, etc. The in vivo experiment also testified that it could promote the bone defect repair in rat models. These results indicate the multifunctional hydrogel is an ideal material for the treatment of bone defects and has good clinical application potential.
The Impact of Department of Justice Reform Agreements on Arrest Rates and Racial Disparity Within Arrests
Authors: Skinner John
Published: July 2024

Section 14141 of the Violent Crime Control Act of 1994 gave the Department of Justice (DOJ) the authority to investigate institutional misconduct and compel reform within local police agencies. The focus of DOJ reform efforts is often directed at disrupting patterns of discriminatory policing practices within targeted police departments. DOJ-led investigations have found that many police departments identified for federal oversight have historically engaged in discriminatory and bias-based enforcement strategies. These strategies frequently result in a disproportionate volume of stops, searches, and arrests of minority populations. The racial disparity found in these enforcement strategies often deteriorates the trust and legitimacy of police officers. This article provides an evaluation of the impact of DOJ intervention on arrest rates and patterns of racial disparity in arrests within large city police departments. The analysis uses arrest data compiled from the Uniform Crime Reports to compare arrest patterns across major city police agencies that participated and did not participate in DOJ reform agreements focused on discriminatory enforcement between 1995 and 2018. This article approaches this evaluation through a heterogeneous difference-in-difference analysis that uses both attributable risk and relative risk measurements to compare the racial disparity within arrest trends during and after DOJ reform intervention.
Exploring Cybercrime Capabilities: Variations Among Cybercrime Investigative Units
Authors: Steinmetz Kevin F. , Schaefer Brian P. , McCarthy Adrienne L. , Brewer Christopher G. , Kurtz Don L.
Published: July 2024

The current analysis utilizes semi-structured qualitative interviews with sworn cybercrime detectives, civilian digital forensics analysts, and unit administrators to consider variations between cybercrime units which bear significant implications for cybercrime investigative policy and practice. The first variation observed in this study concerns differences in the structure of digital forensics assignments. Such duties may be assigned to sworn officers, civilians, sworn officers and civilian, outsourced to other departments, or a dedicated forensic lab. Second, variations between units were noted in resource availability (tools, training, and finances). These variations among cybercrime units may have implications for personnel recruitment and retention, the sophistication of cases considered by investigators, and case success.
What Motivates Employer Engagement? Promoting Youth Career Embeddedness in Two Tennessee Regions
Authors: Myers Jenna E.
Published: July 2024

While workforce development can create skilled workers and better jobs, employer engagement is often limited. This article analyzes the case of Tennessee Pathways and draws on interviews with highly engaged employers, including those that hosted youth worker interns. The author investigates how employers accounted for their involvement and how program design shaped the benefits they perceived. Despite a traditional focus on skills gaps, the author finds that most employers sustained their engagement due to workforce challenges rooted in a mismatch between new hires’ expectations and the realities of the job, which resulted in high turnover of incumbent adult workers. Employers perceived that youth programs addressed this issue by fostering “career embeddedness” and deepening youth workers’ commitment to a nascent career interest or by redirecting them to other viable options. The author argues that practitioners should promote the potential of workforce development to yield long-term workforce reproduction and next-generation career development.
Being Responsible in a Polarized World: From Dialogical to Partisan CSR
Authors: Gualtieri Gastone , Lurati Francesco
Published: July 2024

This paper investigates how companies approach corporate social responsibility in polarized landscapes. Polarization makes the dominant dialogical approach to CSR potentially inconclusive. Indeed, companies cannot orient societal CSR meanings through an all-stakeholder-inclusive dialogue because, in a polarized world, stakeholders form alternative meanings in separate and mutually delegitimizing conversations. To understand how companies try to appear responsible under these circumstances, we examine Italian telecom companies’ CSR reports issued throughout the launch of 5G technologies, a polarizing topic that sparked fake news and conspiracy theories. The findings show that, in such polarizing circumstances, companies may adopt a partisan approach to CSR, i.e., engaging with only one conversation to shape CSR views within it while ignoring the other. Through this approach, companies may further exacerbate polarization and shape CSR meanings to align with their core business, rather than the opposite. These implications, we argue, might jeopardize the very essence of CSR.
Exploring the Benefits of Boundarylessness: Pathways From Boundaryless Career Orientation to Insecurity and Engagement
Authors: Mazzetti Greta , Alcover Carlos-María , Çetin Mehmet , De Carlo Elisa , Derous Eva , Guglielmi Dina
Published: July 2024

The increasing demand for flexibility and adaptability among workers underscores the necessity to explore the outcomes of enhanced proactivity in employees. This study explores the role of job crafting and career competencies (i.e., knowing why, knowing how, and knowing whom) in the relationship between boundaryless career orientation and opposite indicators of subjective career success (i.e., work engagement and job insecurity). Data collected on a sample of 1431 Italian workers (75.5% females; Mage = 37.95) were tested using nested models via Structural Equation Modeling. The results provided support for a significant serial mediation pathway from boundaryless career orientation to work engagement and perceived job insecurity through the subsequent role of job crafting and career competencies. This study sheds light on the protective role of a boundaryless career orientation in fueling a proactive attitude to navigate the progressive fading of traditional career paths and employment stability while sustaining workers’ engagement.
The edTPA as a Barrier to Preparing Antiracist Teachers in California
Authors: Vachon Kimberly J.
Published: July 2024

This paper explores the policy, pedagogy, and practice affordances and constraints of teacher education as an environment to develop pre-service teachers’ antiracism commitments. Through critical analysis of interviews with pre-service teachers and teacher educators at three social justice-oriented teacher preparation programs, research findings indicate that the material consequences of passing the edTPA can lead pre-service teachers to deprioritize the antiracist or equitable frameworks that were emphasized in their program. The edTPA’s inattention to racism and antiracist practice signals an irrelevance to some pre-service teachers. These findings have implications for how teacher educators may approach the edTPA in social justice-oriented programs.
The Refiguration of the Global: Globalization and the Spatial Logics of Digitalization
Authors: Knoblauch Hubert , Löw Martina
Published: July 2024

In order to avoid the juxtaposition of globalization and de-globalization, we suggest that the current global changes are driven by a spatial dynamics, which we designate as ‘refiguration’. It is based on different spatial figures and different institutionalized figurations, so as to avoid reducing the dynamics to binary concepts of territorial and global forces or geopolitical spatial container thinking. In this paper, we first sketch the strengths and weaknesses of sociological models of globalization. We then point out some recent developments contradicting these models. Instead of interpreting them negatively (e.g. ‘de-globalization’) or reductively (e.g. ‘geopolitization’), we propose the concept of refiguration in order to capture and explain these current changes by stressing the logics of spatial figures, their interactions and conflicts. After clarifying the concept, we turn to the Internet infrastructure as an important case for understanding the current disjunctures and conflicts around globalization in terms of refiguration.
Toward predicting entrepreneurial activity among Moroccan Entrepreneurs: A machine learning approach
Authors: Boutaky Ghizlane , Youb Ibtissam , Dokou Kokou Gerard , Mialed Karima , Vernier Eric , Hamlich Mohamed , Ventura Sebastián , Boutaky Soukaina
Published: July 2024

Entrepreneurial activity, a subject of enduring intrigue among scholars, continues to captivate attention, especially in distinct contexts such as Morocco. This study undertakes the formidable task of comprehending and forecasting entrepreneurial activity using the comprehensive Global Entrepreneurship Monitor (GEM) dataset for Morocco. Employing a diverse range of machine learning classifiers, including logistic regression, random forest, support vector machines, gradient boosting, and K-nearest neighbors, our research excels in predicting entrepreneurial activity with remarkable accuracy. Notably, support vector machines emerge as the most potent classifier, achieving an impressive accuracy rate of 95.33%. These findings transcend the inherent complexities of understanding the infrequent nature of entrepreneurial activity, providing invaluable insights into predictive modelling within the Moroccan entrepreneurial landscape. This research not only advances our comprehension of entrepreneurship but also paves the way for informed policymaking and the nurturing of a thriving entrepreneurial ecosystem. This underscores the critical importance of effective data handling and model refinement in achieving these milestones.
Research on low-expansion metamaterial technique of four-leaf clover bionic structure
Authors: Wang Meng , Shen Xin , Wu Yipeng , Sun Beibei
Published: July 2024

A new metamaterial structure has been developed with ultra-low expansion characteristics, featuring a unidirectional thermal expansion coefficient of less than 1 × 10−7/°C. Metamaterial structure is a new type of composite material designed artificially, by combining material technology with mechanical design technology, to achieve properties that cannot be achieved by conventional materials. Using the metamaterial design method, two materials with a large difference in thermal expansion coefficient are selected to design and realize the negative expansion unit structure. Combining the designed negative expansion structure and the conventional structure with positive expansion, the ultra-low expansion characteristics are finally realized through the mutual compensation of the thermal deformation properties of the two. The ultra-low thermal expansion characteristics of the novel metamaterial structures are verified through material modeling and simulation analysis.
Numerical study on local contact conditions on rough surface under press hardening
Authors: Deng Liang
Published: July 2024

The primary concern for manufacturers related to press hardening is productivity, which can deteriorate owing to wear. Severe tribological behaviours, such as abrasive and adhesive wear, lead to blank rupture, surface scratches and shape deviation of the formed parts, increasing the cost and time required for maintenance. To understand the mechanism governing tribological behaviours during consecutive stamping strokes, this study proposes a finite element (FE) simulation of the interface between the blank and tool steel. The FE simulation involves measuring the surface topography in a real stamping tool to obtain local contact conditions. The effects of the nominal pressure and range of the friction coefficient on the local contact conditions were studied. A tribological test capable of accurately reproducing the press hardening conditions was conducted to validate FE simulation. The local contact conditions in terms of contact pressure, contact area and sliding distance were found to differ from the nominal values. The proposed FE simulation involving a rough surface explores the possible length scale of the surface topography, wherein the calculated parameters are likely the main factors affecting wear. Furthermore, the correlation between the test variables and local contact conditions can help optimise the process parameters and lubricity.
Mechanical characterization and study on morphological properties: Natural and agro waste utilization of reinforced polyester hybrid composites
Authors: Vinoth V , Sathiyamurthy S , Ananthi N , Jayabal S
Published: July 2024

Eco-conscious products are currently garnering significant attention due to their abundant availability and versatile applications in various engineering contexts. The distinctive properties of natural fibers make them readily substitutable for synthetic fibers. A substantial one million tonnes of fiber waste, primarily composed of paddy straw fiber, is generated globally. The research emphasis revolves around the adoption of the Waste to Wealth technique, a highly efficient process aimed at repurposing waste materials. This approach plays a pivotal role in curbing air pollution, specifically by preventing the incineration of the residual portion of paddy straw fiber on agricultural lands. The study involves the collection of paddy straw fiber from agricultural fields, with subsequent extraction facilitated by an extracting machine. Employing a chemical treatment process enhances the adhesion properties between the fiber and matrix. Consequently, comprehensive fiber tests, including the single fiber test, fiber tenacity, and fiber fineness, were meticulously examined for both treated and untreated fibers. The reinforcements and matrix were taken by the weight percentage of 50:50 with different fiber length (25, 50, 75, 100 mm) using the compression moulding machine with 300 mm × 300 mm × 3 mm dimensions. After making the laminates, the samples were cut as per the ASTM standard. The mechanical and morphological behavior of the hybrid fiber-reinforced polyester composites were evaluated, and the water absorption property in the concerned laminates was studied.
Mechanical comprehensive evaluation model and sealing performance research of rubber cylinder at large pressure and high temperature
Authors: Zhang Lan , Wen Jing , Zhang Hang , Zhang Guoqiang , Liu Ming , Yun Feihong , Shang Shoubo
Published: July 2024

The submarine pipe stopper is prone to failure at large pressure and high temperature conditions. This work focuses on the submarine pipe stopper’s sealing failure caused by excessive shear stress and high temperature. First, the working principle of the sealing device in the stopper was analyzed and its performance was verified through land and sea trials. Then a comprehensive evaluation model fit for the large working pressure was established by analyzing the rubber cylinder’s sealing performance and strength. Next, the model was modified by simulation using the nitrile rubber (NBR) cylinder and the fluororubber (FKM) cylinder were used as examples to revise the comprehensive evaluation model while taking temperature into account. The maximum contact stress and the maximum shear stress of the NBR rubber cylinder at 100°C increased by 28% and 30.62% compared to 25°C, and that of the FKM rubber cylinder increased by 24% and 26.12%. In comparison to 25°C, the maximum contact stress and maximum shear stress of the NBR rubber cylinder increased by 28% and 30.62% at 100°C, while the FKM rubber cylinder had an increase of 24% and 26.12%. At 100°C, the NBR rubber cylinder exhibits a maximum contact stress of 4.71 MPa and a maximum shear stress of 1.18 MPa, whereas the FKM rubber cylinder displays maximum contact and shear stresses of 5.09 and 2.44 MPa. Finally, the rubber cylinder’s maximum working pressure at different temperatures was derived, and the influence of its parameters was discussed. The maximum working pressure at 100°C is only 21% of what the rubber cylinder can bear at 25°C. This work is of great significance for accurately evaluating the rubber cylinder’s sealing performance in the submarine pipe stopper and provides new ideas for the rubber cylinder’s design at high-temperature conditions.
Research on collaborative multi-UAV localization method based on combination navigation information
Authors: Cao Zhengyang , Chen Gang
Published: July 2024

In challenging environments, unmanned aerial vehicle (UAV) systems often encounter unstable satellite signals and communication link interference. This paper proposes an integrated navigation method that integrates inertial navigation system (INS), global navigation satellite system (GNSS), and visual navigation system (VNS). Utilizing data from onboard sensors, this method merges relative navigation information from feature tracking of multiple UAVs with each UAV’s absolute navigation data. It includes specially designed transmission rules to reduce data exchange between UAVs. Each UAV uses an adaptive unscented Kalman filter (AUKF) method, which is enhanced into a collaborative AUKF (C-AUKF) using a message passing-based approach. Experiments in a simulated mission scenario revealed that the C-AUKF, in comparison to using extended Kalman filter (EKF), significantly improved flight test performance across the entire testing area, with a cumulative deviation of only 10.22 m, about 0.85% of the total flight distance. These results demonstrate that the proposed method not only meets accuracy requirements for position and velocity in integrated navigation but also significantly enhances multi-UAV navigation precision, particularly in scenarios with global positioning system (GPS) interference.
Mechanical and microstructural investigation of three-dimensionally printed PEEK polymer
Authors: Karunanithi Chithambaram , Natarajan Senthilnathan
Published: July 2024

Three-dimensional polymer printing is becoming more popular due to its effectiveness in creating components of any geometric design. Polymer materials can be used at low temperatures but are weaker than other functional materials. Polyetheretherketone (PEEK) is a thermoplastic with outstanding mechanical properties that can tolerate high temperatures. A high-temperature fused deposition modeling machine manufactured PEEK specimens in this experiment to find the ideal printing parameters S1, S2, S3, and S4 were made using varying printing speeds and layer thicknesses. The polymer sample’s exterior surface was analyzed using FESEM, while physical characterization was conducted through X-ray diffraction analysis and water contact angle measurement. The strength of each sample in the relevant variables was determined using mechanical testing, such as tensile and compression tests. It was found that specimen S3 having a layer thickness of 0.15 mm and printing speed of 20 mm/s showed a high tensile and compressive strength value of about 78 and 144 MPa respectively than the other three samples. In addition, the fractured tensile samples were analyzed with scanning electron microscopy to discover the factors that contributed to the disparity in the values of their strengths.
Research on energy saving and control characteristics of back pressure controllable variable speed pump controlled steering system for heavy vehicles
Authors: Du Heng , Li Hanjin , Ding Kaiyi , Li Su , Yu Jianchao
Published: July 2024

Steering system of heavy vehicle facing intelligent and green development needs to satisfy the requirements of high precision and energy-efficient dynamic steering. Traditional steering systems use valved servo systems, which offer high steering accuracy but result in significant energy dissipation at the valve ports. In contrast, the variable speed pump control system (VSPCS) realizes the precise servo of steering system through direct volume control, which basically eliminates the energy dissipation at the valve port. However, the VSPCS lacks sufficient system stiffness due to low back pressure, making it difficult to achieve precise steering. To address these limitations, this paper proposes a back pressure controllable variable speed pump controlled steering system scheme (BCVSPCSS), which combines the energy-efficient flow supply of the VSPCS with a servo-proportional valve is used for back pressure control to, improving the dynamic performance of the system. This integration allows for precise steering while maintaining energy efficiency; The design of a dual objective nonlinear control strategy for angle and back pressure is crucial to deal with uncertainty and nonlinearity in the system. The Lyapunov analysis shows that the closed-loop system has asymptotic stability. In this paper, the experimental bench of BCVSPCSS is built for experimental verification. The results show that back pressure control effectively enhances the system’s immunity. Under the same working conditions, the maximum angle error of the two systems is roughly the same, both around 1°, while the energy consumption of BCVSPCSS is reduced by about 84.6% compared to the valve controlled steering system.
Surface roughness prediction in turning processes using CEEMD-based vibration signal denoising and LSTM networks
Authors: Athisayam Andrews , Kondal Manisekar
Published: July 2024

Surface roughness plays a pivotal role in assessing machining quality, and numerous research efforts have been devoted to predicting surface roughness in turning processes primarily based on cutting parameters. However, it's important to recognize that surface roughness isn’t solely governed by cutting parameters; it is also influenced by tool characteristics, workpiece properties, and the prevailing machining conditions. Therefore, the accurate prediction of surface roughness during turning operations is of utmost importance for facilitating timely corrective measures. However, the accuracy of prediction is affected by the intense background noise and usage of manual feature extraction. To address these issues, this article proposes a novel method combining the complete ensemble empirical mode decomposition (CEEMD) and sequence long short-term memory (LSTM) networks. The CEEMD decomposes the measured vibration signals, and noise-free intrinsic mode functions (IMFs) are chosen based on cross-correlation. The noise-free IMFs are then reconstructed to get the denoised signal. The denoised signals are fed straight into the Sequence LSTM network, a deep learning-based prediction algorithm for accurate prediction. The network parameters are optimized to minimize the error. An experimental study was conducted to assess the suggested method, and the results show that it effectively predicts surface roughness during turning using vibration signals. Further, the proposed approach has proven effective compared with other denoising methods. The proposed method has significant applications in the manufacturing industry, where it can contribute to better quality control and process optimization.
Breaking boundaries: Optimizing dry machining for AISI D4 hardened tool steel through hybrid ceramic tool inserts
Authors: Rath Debabrata , Alamry A. , Kumar Sudhir , Padhi Pratap Chandra , Pattnaāik Pratyush
Published: July 2024

The conventional approach to high-speed turning of AISI D4 hardened steel often encountered challenges, notably elevated temperatures at the tool–workpiece interface and resultant surface quality degradation, particularly when utilizing CBN and ceramic inserts at cutting speed exceeding 200 m/min. In response to these limitations, this study presents a novel methodology employing a coated tin layered insert comprised of aluminum oxide (Al2O3)-Ti (C, N) for dry machining of AISI D4 steel. A significant contribution of this work lies in establishing a quantitative relationship between process variables and response characteristics, alongside process optimization facilitated by the Taguchi method design of experiment approach. By employing a selected hybrid ceramic insert, the study achieves sustainable dry machining of AISI D4 steel. Multiresponse analysis reveals that optimal machining parameters include a cutting speed (Cs) of 170 m/min, feed rate of 0.03 mm/rev, and depth of cut (DoC) of 0.4 mm, resulting in a minimum surface roughness of 0.76 µm. Analysis of variance underscores the pivotal role of feed rate and DoC in shaping surface characteristics, with statistical significance ( p-value < .05), while cutting speed proves insignificant ( p-value > .05). Furthermore, SEM micrographic examination substantiates the superior performance of hardened D4 steel, renowned for its exceptional resistance to wear and oxidation, rendering it indispensable in the fabrication of various tools including dies, press tools, punches, and bushes, surpassing current machining methodologies.
Thermophysical traits of hybrid nanofluids in cleanroom air handling unit: An experimental study
Authors: Dolui Sujoy Kumar , Babu A. Veeresh , Reddy T. Srinivas
Published: July 2024

Nanofluids, comprising colloidal suspensions of non-metallic or metallic nanoparticles dispersed in conventional base fluids, are crucial for augmenting heat transfer properties across numerous industrial sectors. Cleanroom facilities play a vital role in diverse industries by regulating contamination levels and environmental parameters to ensure optimal operational conditions. In this paper, thermophysical characteristics of mono nanofluids (Al2O3–water, CuO–water) and hybrid nanofluid (Al2O3–CuO–water) at various nanoparticle concentrations (1%, 1.5%, 2%, 2.5%, 3%, 3.5% and 4%) on a prototype cleanroom air handling chiller unit was investigated experimentally. An experimental investigation on the thermophysical characteristics of mono and hybrid nanofluids in a prototype cleanroom air handling chiller unit heat exchanger with an increasing nanoparticle volume concentration from 1% to 4% revealed that the density increased by 9.27%, 16.67% and 25.91%; specific heat decreased by 2.53%, 2.66% and 2.17%; thermal conductivity increased by 15.71%, 14.70% and 16.67%; and dynamic viscosity increased by 32.94%, 32.47% and 32.90% for Al2O3–water, CuO–water and hybrid (Al2O3–CuO–water) nanofluids, respectively, in comparison with water. The novelty of this research lies in its investigation of hybrid nanofluids tailored for cleanroom air handling units, aiming to enhance heat transfer efficiency, offering valuable insights by characterising thermophysical traits and assessing their performance for advancing cleanroom technology, addressing a significant research gap in the field.
Job tenure in Western Europe, 1993–2021: Decline or stability?
Authors: Goulart Kimberly , Oesch Daniel
Published: July 2024

The empirical literature is divided on whether job tenure has declined or remained stable in Europe in recent decades. We argue that three analytical decisions explain the lack of consensus: whether researchers focus on men or women, whether they control for changes in labour market composition and whether the period under study is marked by a recession or a boom. We show the influence of these three decisions by analysing change in job tenure for France, Germany, Italy, Poland, Spain and the UK using two leading surveys: the European Labour Force Survey 1993–2021 and the European Working Conditions Survey 1995–2021. The results show that the share of workers remaining with the same employer for 10 years or more was stable at around 50%. Similarly, the average job tenure remained constant over time – at about 11 years – between 1993 and 2021. Trends in job tenure differ by gender. While the tenure of men remained stable or declined, the tenure of women increased. The stability in job tenure was due to the ageing of the workforce. For a given age, job tenure was shorter in the early 2020s than in the early 1990s.
Deadly ambiguities: NATO and the politics of counter-terrorism in international organizations after 9/11
Authors: Pomarede Julien
Published: July 2024

The article investigates the social making of counter-terrorism in international organizations (IOs). Discussing the literatures that emphasize the (in)coherence of multilateral counter-terrorism and the diversity of interests that interact and converge in these policies, the article highlights the determinants by which an object as vague and dissensual as post-9/11 counter-terrorism is ordered and stabilized within IOs. Therefore, the article provides an alternative sociological exploration of counter-terrorism in IOs by delving into the dynamics of frictions and power. Multilateral counter-terrorism is conceptualized as a socially grounded ‘constructive ambiguity’; the catch-all category of counter-terrorism is both a patent source of conflict among IOs’ players, who fight over its meaning, and a catalyser of minimal consensus. The article isolates two types of power structures in IOs that the ambiguity of counter-terrorism supports: domination and fragmentation. Additionally, the article demonstrates how ambiguities condition the conduct and evolution of IOs’ risk management security agenda. To do so, the article takes NATO’s post-9/11 trajectory as a case study and explores two different counter-terrorism policies related to counterinsurgency warfare in Afghanistan and maritime surveillance in the Mediterranean Sea.
Drama and Theatre: How They Changed Their Vagabond Past and Became Educational and Clinical Specialisms
Authors: Jennings Sue
Published: July 2024

Dramatic performance through rituals and ceremonies has an ancient and respected past, for celebration, status confirmation, and healing. This is particularly so in non-Western cultures. However, in the United Kingdom and the West, it has had a chequered development, and actors for many years were considered vagabonds and of questionable reputation. Initiatives in drama and theatre in education enabled the development of drama as a therapy. However, there was less emphasis on the art form, as in other arts therapies, and more focus on techniques. Performance for healing in dramatherapy slowly became eroded. Parallel to drama as a therapy, psychodrama slowly emerged as an approach to therapeutic applications of role-play. Attention is drawn to the very early dramatic expression, through neuro-dramatic-play, commencing during pregnancy.
Unraveling Sociocultural Influences on Leptospirosis Incidence and Prevalence: A Qualitative Study in Sri Lanka
Authors: Udayanga Samitha , Kankanamge Dinesha , Gamage Thilini , Suresh De Zoysa Lahiru , Chamathya Yasasi , Bellanthudawa BKA , Batuwanthudawa Samadara , Ruwanpathirana Nirosha , Gayashan Nimantha , Gunasekara Suranjith , Chandana EPS
Published: July 2024

This study aimed to explore sociocultural determinants that might contribute to the increased prevalence and incidence of leptospirosis, and how those determinants can also hinder health promotion interventions, particularly in rural areas of Sri Lanka. Even though several epidemiological studies have been conducted on leptospirosis in the Asia-Pacific region, the sociocultural background of this disease has not received sufficient attention. Therefore, through a qualitative study involving nine public health officials and 25 infected patients in five selected health administrative divisions, we demonstrate that a set of certain sociocultural determinants influence leptospirosis incidence and its prevalence. The thematic analysis generated six themes: a lack of knowledge of the causes and consequences of leptospirosis, false illness interpretations, a lack of readiness for the disease, poor economic conditions, social capital failure, and issues within the health system at the community level. Overall, results suggest that awareness programs aimed at demystifying false interpretations of leptospirosis lie at the center of any health promotion interventions at the community level.
Is It Time to Ban Flavored Cigarettes in Asia-Pacific Countries? A Scoping Review
Authors: van der Eijk Yvette , Tan Grace Ping Ping , Makhbal Binderiya
Published: July 2024

Flavored cigarettes encourage youth smoking and deter quitting. No country in Asia-Pacific, a region with some of the world’s highest smoking rates, has regulated tobacco flavors. We examined market data, academic literature, and gray literature to describe what is known on flavored cigarettes in the Asia-Pacific region. Of the 12 countries for which market data were available, ten had substantial flavored cigarette market shares ranging from 10% to 97%. With no regulations and growing markets for flavor capsule variants, the tobacco industry’s ongoing promotion of flavored cigarettes, which targets primarily youth and women, is expected to drive further increases in smoking prevalence. There are significant research and monitoring gaps on the industry’s marketing tactics and use of flavored cigarettes in the region. Given the large market shares, Asia-Pacific countries stand to benefit substantially from a tobacco flavors ban.
The multiple logics of Buddhist monastery accounting
Authors: Chandrasena Supun , Quinn Martin
Published: July 2024

Research has shown that Buddhist monasteries’ accounting provides detailed and fulfilling accountability requirements to rulers and the public. However, what influenced such practices is under-researched. In bridging this gap, this study adopts an institutional logic framing and identifies three institutional logics: devotional, public and private that appear to have shaped early accounting thought and practices in Ceylonese Buddhist monasteries. The research comprises the analysis of English translations of 122 inscriptions dating from the first to the sixteenth century. The analysis reveals the co-existence and mutual dependence of the three logics, concluding that these logics influenced accounting at the same time. The accounts are also important tools to maintain the co-existence of these competing institutional logics, highlighting a dynamic two-way relationship between logics and accounting. The study demonstrates the role of accounting as a bridging mechanism, temporarily combining logics to exploit complementarities between them, maintain the hybridity of monasteries and preserve their legitimacy. The ability of accounting to represent all logics enables the stability of monasteries over time.
Health justice partnership: Access to justice meets health equity
Authors: Forell Suzie , McCarron Emily
Published: July 2024

Access to justice research identifies how unmet legal need arises from and exacerbates disadvantage. In parallel, epidemiological research identifies the inequitable impact of social determinants on health. Health justice partnership (HJP) is an innovative response to this evidence: providing accessible legal help to individuals experiencing complex needs; building the capability of health and legal services to support these clients; and challenging systemic factors that contribute to social and health inequity. HJP offers a broader view of access to justice, demonstrating how the law and accessible legal help contribute to health and wellbeing outcomes, and are part of the shared challenge of responding to health and social inequity.