bluuebunny/crossref_metadata_2025 huggingface dataset:
Kia Tīmata Pai (Best Start): a study protocol for a cluster randomised trial with early childhood teachers to support children’s oral language and self-regulation development
Authors: Reese Elaine , Kokaua Jesse , Guiney Hayley , Bakir-Demir Tugce , McLauchlan Jimmy , Edgeler Clair , Schaughency Elizabeth , Taumoepeau Mele , Salmon Karen , Clifford Amanda , Maruariki Natasha , McNaughton Stuart , Gluckman Peter , Nelson Charles , O'Sullivan Justin , Wei Ran , Pergher Valentina , Amjad Sophia , Trudgen Anita , Poulton Richie
Published: September 2023

Introduction

Oral language skills are associated with children’s later self-regulation and academic skills; in turn, self-regulation in early childhood predicts successful functioning later in life. The primary objective of this study is to evaluate the separate and combined effectiveness of an oral language intervention (Enhancing Rich Conversations, ENRICH) and a self-regulation intervention (Enhancing Neurocognitive Growth with the Aid of Games and Exercise, ENGAGE) with early childhood teachers and parents for children’s oral language, self-regulation and academic functioning.

Methods and analysis

The Kia Tīmata Pai (Best Start) study is a cluster randomised controlled trial with teachers and children in approximately 140 early childhood centres in New Zealand. Centres are randomly assigned to receive either oral language intervention only (ENRICH), self-regulation intervention only (ENGAGE), both interventions (ENRICH+ENGAGE) or an active control condition. Teachers’ and parents’ practices and children’s oral language and self-regulation development are assessed at baseline at age 1.5 years and approximately every 9 months to age 5, and academic performance at age 6. Teacher–child interactions will also be videotaped each year in a subset of the centres. Children’s brain and behaviour development and parent–child interactions will be assessed every 6 months to age 6 years in a subgroup of volunteers.

Ethics and dissemination

The Kia Tīmata Pai trial and the two substudies (Video Project; Brain and Behaviour Development) have been approved by the University of Otago Human Ethics Committee (Health; H20/116), and reviewed for cultural responsiveness by: the Ngāi Tahu Research Committee (University of Otago), the Māori Advisory Group (University of Auckland, Liggins Institute) and an internal cultural advisory group. Results will be disseminated in international and national peer-reviewed academic journals and communicated to local, national and international organisations serving early childhood teachers, parents and young children. Data will be available via communication with the corresponding author.

Trial registration number

ACTRN12621000845831.
Robotic and laparoscopic gynaecological surgery: a prospective multicentre observational cohort study and economic evaluation in England
Authors: McCarthy Andrew , Samarakoon Dilupa , Gray Joanne , Mcmeekin Peter , McCarthy Stephen , Newton Claire , Nobbenhuis Marielle , Lippiatt Jonathan , Twigg Jeremy
Published: September 2023

Objective

To compare the health-related quality of life and cost-effectiveness of robot-assisted laparoscopic surgery (RALS) versus conventional ‘straight stick’ laparoscopic surgery (CLS) in women undergoing hysterectomy as part of their treatment for either suspected or proven gynaecological malignancy.

Design

Multicentre prospective observational cohort study.

Setting

Patients aged 16+ undergoing hysterectomy as part of their treatment for gynaecological malignancy at 12 National Health Service (NHS) cancer units and centres in England between August 2017 and February 2020.

Participants

275 patients recruited with 159 RALS, 73 CLS eligible for analysis.

Outcome measures

Primary outcome was the European Organisation for Research and Treatment of Cancer Quality of Life measure (EORTC). Secondary outcomes included EuroQol-5 Dimension (EQ-5D-5L) utility, 6-minute walk test (6MWT), NHS costs using pounds sterling (£) 2018–2019 prices and cost-effectiveness. The cost-effectiveness evaluation compared EQ-5D-5L quality adjusted life years and costs between RALS and CLS.

Results

No difference identified between RALS and CLS for EORTC, EQ-5D-5L utility and 6MWT. RALS had unadjusted mean cost difference of £556 (95% CI −£314 to £1315) versus CLS and mean quality adjusted life year (QALY) difference of 0.0024 (95% CI −0.00051 to 0.0057), non-parametric incremental cost-effectiveness ratio of £231 667per QALY. For the adjusted cost-effectiveness analysis, RALS dominated CLS with a mean cost difference of −£188 (95% CI −£1321 to £827) and QALY difference of 0.0024 (95% CI −0.0008 to 0.0057).

Conclusions

Findings suggest that RALS versus CLS in women undergoing hysterectomy (after adjusting for differences in morbidity) is cost-effective with lower costs and QALYs. Results are highly sensitive to the usage of robotic hardware with higher usage increasing the probability of cost-effectiveness. Non-inferiority randomised controlled trial would be of benefit to decision-makers to provide further evidence on the cost-effectiveness of RALS versus CLS but may not be practical due to surgical preferences of surgeons and the extensive roll out of RALS.
Exploring the association between congenital vertebral malformations and neural tube defects
Authors: Ye Yongyu , Zhang Jianan , Feng Xin , Chen Chong , Chang Yunbing , Qiu Guixing , Wu Zhihong , Zhang Terry Jianguo , Gao Bo , Wu Nan
Published: September 2023

Congenital vertebral malformations (CVMs) and neural tube defects (NTDs) are common birth defects affecting the spine and nervous system, respectively, due to defects in somitogenesis and neurulation. Somitogenesis and neurulation rely on factors secreted from neighbouring tissues and the integrity of the axial structure. Crucial signalling pathways like Wnt, Notch and planar cell polarity regulate somitogenesis and neurulation with significant crosstalk. While previous studies suggest an association between CVMs and NTDs, the exact mechanism underlying this relationship remains unclear. In this review, we explore embryonic development, signalling pathways and clinical phenotypes involved in the association between CVMs and NTDs. Moreover, we provide a summary of syndromes that exhibit occurrences of both CVMs and NTDs. We aim to provide insights into the potential mechanisms underlying the association between CVMs and NTDs, thereby facilitating clinical diagnosis and management of these anomalies.
Beyond antithrombotics: recent advances in pharmacological risk factor management for secondary stroke prevention
Authors: Sagris Dimitrios , Ntaios George , Milionis Haralampos
Published: September 2023

Patients with ischaemic stroke represent a diverse group with several cardiovascular risk factors and comorbidities, which classify them as patients at very high risk of stroke recurrence, cardiovascular adverse events or death. In addition to antithrombotic therapy, which is important for secondary stroke prevention in most patients with stroke, cardiovascular risk factor assessment and treatment also contribute significantly to the reduction of mortality and morbidity. Dyslipidaemia, diabetes mellitus and hypertension represent common and important modifiable cardiovascular risk factors among patients with stroke, while early recognition and treatment may have a significant impact on patients’ future risk of major cardiovascular events. In recent years, there have been numerous advancements in pharmacological agents aimed at secondary cardiovascular prevention. These innovations, combined with enhanced awareness and interventions targeting adherence and persistence to treatment, as well as lifestyle modifications, have the potential to substantially alleviate the burden of cardiovascular disease, particularly in patients who have experienced ischaemic strokes. This review summarises the evidence on the contemporary advances on pharmacological treatment and future perspectives of secondary stroke prevention beyond antithrombotic treatment.
Assessing treatment response to oral drugs for multiple sclerosis in real-world setting: a MAGNIMS Study
Authors: Ruggieri Serena , Prosperini Luca , Al-Araji Sarmad , Annovazzi Pietro Osvaldo , Bisecco Alvino , Ciccarelli Olga , De Stefano Nicola , Filippi Massimo , Fleischer Vinzenz , Evangelou Nikos , Enzinger Christian , Gallo Antonio , Garjani Afagh , Groppa Sergiu , Haggiag Shalom , Khalil Michael , Lucchini Matteo , Mirabella Massimiliano , Montalban Xavier , Pozzilli Carlo , Preziosa Paolo , Río Jordi , Rocca Maria A , Rovira Alex , Stromillo Maria L , Zaffaroni Mauro , Tortorella Carla , Gasperini Claudio
Published: September 2023

Background

The assessment of treatment response is a crucial step for patients with relapsing-remitting multiple sclerosis on disease-modifying therapies (DMTs). We explored whether a scoring system developed within the MAGNIMS (MRI in Multiple Sclerosis) network to evaluate treatment response to injectable drugs can be adopted also to oral DMTs.

Methods

A multicentre dataset of 1200 patients who started three oral DMTs (fingolimod, teriflunomide and dimethyl fumarate) was collected within the MAGNIMS network. Disease activity after the first year was classified by the ‘MAGNIMS’ score based on the combination of relapses (0–≥2) and/or new T2 lesions (<3 or ≥3) on brain MRI. We explored the association of this score with the following 3-year outcomes: (1) confirmed disability worsening (CDW); (2) treatment failure (TFL); (3) relapse count between years 1 and 3. The additional value of contrast-enhancing lesions (CELs) and lesion location was explored.

Results

At 3 years, 160 patients experienced CDW: 12% of them scored ‘0’ (reference), 18% scored ‘1’ (HR=1.82, 95% CI 1.20 to 2.76, p=0.005) and 37% scored ‘2’ (HR=2.74, 95% CI 1.41 to 5.36, p=0.003) at 1 year. The analysis of other outcomes provided similar findings. Considering the location of new T2 lesions (supratentorial vs infratentorial/spinal cord) and the presence of CELs improved the prediction of CDW and TFL, respectively, in patients with minimal MRI activity alone (one or two new T2 lesions).

Conclusions

Early relapses and substantial MRI activity in the first year of treatment are associated with worse short-term outcomes in patients treated with some of the oral DMTs.
Isolation of an antimicrobial racemic phenalenone derivative from a marine-derived Penicillium sp. fungus
Authors: Morehouse Nicholas J. , Graham Kelsie M. , Cox Samantha L. , Johnson John A. , Gray Christopher A.
Published: September 2023

A new phenalenone derivative, 2,4,6,9-tetrahydroxy-7-methyl-2-prenyl-1 H-phenalene-1,3(2 H)-dione (1), was isolated from the ethyl acetate extract of a marine-derived Penicillium sp. fungus that exhibited a unique antimicrobial activity profile. The planar structure of 1 was determined through a combination of 1D and 2D NMR experiments, and circular dichroism and polarimetry indicated that it was isolated as a racemic mixture of enantiomers. The antimicrobial activity of 1 was assessed against a panel of gram-positive and gram-negative bacteria and fungal strains, and it was found to selectively inhibit the growth of Staphylococcus aureus and Mycobacterium tuberculosis.
A Hybrid Online Off-Policy Reinforcement Learning Agent Framework Supported by Transformers
Authors: Villarrubia-Martin Enrique Adrian , Rodriguez-Benitez Luis , Jimenez-Linares Luis , Muñoz-Valero David , Liu Jun
Published: September 2023

Reinforcement learning (RL) is a powerful technique that allows agents to learn optimal decision-making policies through interactions with an environment. However, traditional RL algorithms suffer from several limitations such as the need for large amounts of data and long-term credit assignment, i.e. the problem of determining which actions actually produce a certain reward. Recently, Transformers have shown their capacity to address these constraints in this area of learning in an offline setting. This paper proposes a framework that uses Transformers to enhance the training of online off-policy RL agents and address the challenges described above through self-attention. The proposal introduces a hybrid agent with a mixed policy that combines an online off-policy agent with an offline Transformer agent using the Decision Transformer architecture. By sequentially exchanging the experience replay buffer between the agents, the agent’s learning training efficiency is improved in the first iterations and so is the training of Transformer-based RL agents in situations with limited data availability or unknown environments.
Steady-state coherence of spin-boson model in a general non-Markovian environment
Authors: Jin Fangqin , You Wen-Long , Dai Yue , Yi Tian-Cheng , Dong Yuli , Zhang Chengjie
Published: September 2023

Based on the quantum coherence theory, we employ the [Formula: see text]-norm measure to explore the steady-state coherence (SSC) in the spin-boson model. In this model, the environment is a non-Markovian bosonic bath with Ohmic-like spectral density. More generally, the interaction coupling between the qubit and the environment is a linear superposition of pure dephasing and pure damping coupling. Governed by the non-Markovian dynamics, some compact expressions of the SSC have been obtained at both zero temperature and high temperature. It shows that the hybrid coupling significantly affects the SSC. Moreover, a comprehensive analysis has been conducted to investigate the effects of various crucial factors, including the temperature of the bosonic bath, the qubit’s tunneling and the Ohmicity parameter. This analysis provides an effective approach for maintaining a relatively high SSC by manipulating system parameters.
Double stratification impacts on MHD flow of micropolar nanofluid over a stretching surface inserted in porous medium
Authors: Anwar M. I. , Ali M. , Lanjwani H. B. , Shehzad S. A.
Published: September 2023

A comprehensive analysis of double stratification impacts on the MHD flow of a nanofluid produced by a porous stretching sheet has been conducted by using a numerical approach. The convective boundary conditions (CBCs) and Newtonian heating (NH) cases have been particularly considered in this problem. The governing equations defined in partial differential equations (PDEs) form are converted into ordinary differential equations (ODEs) by using appropriate transformations to meet the requirement of the used numerical method which is bvp4c in the MATLAB software package. Moreover, the numerical findings of the ODEs are displayed via graphical and tabular forms. The impacts of different flow parameters used in particular problem are discussed for the profiles of the velocity, temperature and concentration of micropolar nanofluid along the values of coefficient of skin-friction [Formula: see text], Nusselt number [Formula: see text], the Sherwood number [Formula: see text] and in relation with the variation parameters in general, CBC and NH are calculated to get a clear insight into the flow situation. Some of the findings show that the skin friction increases by increase in magnetic, permeability and material parameters in all cases but the skin friction is reduced by increasing the thermophoresis parameter for CBC and NH cases, respectively. Microrotation profile decreases when material parameter increases, whereas microrotation profiles enhance with increase of the magnetic field and porosity of porous medium.
On Time-Domain Solutions to the Free Vibration of SDOF Systems with Linear Hysteretic Damping
Authors: Gao Wenjun , Lu Xilin
Published: September 2023

This article focuses on the free vibration of single-degree-of-freedom (SDOF) systems with linear hysteretic damping and investigates the consistency and convergency of the solution to the free vibration in time domain. The criteria associated with the unit-impulse response function at [Formula: see text] are suggested to check the consistency of possible solutions. Exhaustive and systematic derivations are presented to clarify the confusing results in the literature. Subsequently, the integration in the Hilbert term proves to be nonconvergent when an exponential term ([Formula: see text]) is assumed to be the general form of displacement solutions. Hence, it can be concluded that the exact solution to the free vibration of SDOF systems with linear hysteretic damping is still an open question. At last, a numerical verification method is proposed to assess the accuracy of possible solutions.
Numerical Methods for Time-Domain Responses of the Frequency-Independent Damped System
Authors: Sun Panxu , Wang Shuxia , Yan Yadan , Wang Dongwei
Published: September 2023

The complex damping model can only be used to calculate the steady-state responses, while the transient responses are divergent. Based on the complex damping model, the Hilbert transform is introduced to establish a hysteretic damping model, eliminating the divergence phenomenon. However, with the increase of the loss factor, the damped natural frequency also increases. To overcome this shortcoming, a frequency-independent damping model is proposed based on the hysteretic damping model. However, traditional time-domain methods are no longer applicable to frequency-independent damping models. Therefore, the transient response and steady-state response are separated, and the assumption of external excitation acceleration is introduced. Time-domain methods-based linear polynomial assumption, quadratic polynomial assumption and trigonometric function assumption are proposed, respectively. Numerical examples show that the time-domain methods based on linear polynomial assumption and quadratic polynomial assumption have high computational efficiency. But these two methods cannot take into account the vibration frequency of external excitation acceleration. Hence, the computational accuracy is low. Compared with them, the time-domain method based on trigonometric function assumption has the lowest computational efficiency and the highest computational accuracy.
Combination of Optimal Three-Step Composite Time Integration Method with Multi-Point Iterative Methods for Geometric Nonlinear Structural Dynamics
Authors: Shahraki Mojtaba , Shahabian Farzad , Maghami Ali
Published: September 2023

This study focuses on solving the geometric nonlinear dynamic equations of structures using the multi-point iterative methods within the optimal three-step composite time integration method (OTCTIM). The OTCTIM, initially devised for linear dynamic systems, is now proposed to encompass nonlinear dynamic systems in such a way that the semi-static nonlinear equations in time sub-steps can be solved using multi-point methods. The Weerakoon–Fernando method (WFM), Homeier method (HM), Jarrat method (JM), and Darvishi–Barati method (DBM) have been extended as multi-point solvers for nonlinear equations in OTCTIM, which exhibit a higher convergence order than the Newton–Raphson method (NRM), without requiring the calculation of second and higher derivatives. Several structural examples were solved to examine the performance of these methods in the OTCTIM approach. The results demonstrated that the multi-point iterative methods outperform NRM (in terms of the number of iterations) within the OTCTIM for geometric nonlinear structural dynamics and, among the multi-point methods, the JM and DBM converged with fewer number of iterations and lower error levels. Furthermore, it has been observed that when solving nonlinear dynamic equations for structures with a high number of degrees of freedom, the incorporation of the DBM into the OTCTIM mitigates the convergence iterations and the average elapsed time for iterative sub-steps.
Mathematical Modelling and Analytical Dynamic Responses of Blast-Loaded Underground Circular Protective Structures
Authors: Chen Hailong , Feng Jiang , Meng Fanmao , Fan Hualin
Published: September 2023

In this paper, to investigate the dynamic responses of underground circular shells subjected to subsurface denotations and provide a feasible engineering design method, a simplified mathematical modelling was proposed. The dynamic medium–structure interaction (MSI) was introduced into the equations of motions through an interfacial damping between the structure element and the surrounding geomaterial, in which the effects of the shear and the rotary inertia were neglected. By means of modal superposition, the analytical solutions of the dynamic responses were deduced. The effects of geometric parameters and acoustic impedances on the dynamic responses were discussed. It is suggested that protective structures are better to be constructed in geomaterial with small impedance to attenuate the intense shock wave effects.
On constacyclic codes of length 9ps over 𝔽pm and their optimal codes
Authors: Dinh Hai Q. , Ha Hieu V. , Nguyen Nhan T. V. , Tran Nghia T. H.
Published: September 2023

The problem of classifying constacyclic codes over a finite field, both the Hamming distance and the algebraic structure, is an interesting problem in algebraic coding theory. For the repeated-root constacyclic codes of length [Formula: see text] over [Formula: see text], where [Formula: see text] is a prime number and [Formula: see text] does not divide [Formula: see text], the problem has been solved completely for all [Formula: see text] and partially for [Formula: see text]. In this paper, we solve the problem for [Formula: see text] and all primes [Formula: see text] different from [Formula: see text] and [Formula: see text]. In particular, we characterize the Hamming distance of all repeated-root constacyclic codes of length [Formula: see text] over [Formula: see text]. As an application, we identify all optimal and near-optimal codes with respect to the Singleton bound of these types, namely, MDS, almost-MDS, and near-MDS codes.
Creation of periodical domain structure by local polarization reversal in planar waveguide produced by soft proton exchange in LiNbO3
Authors: Savelyev Evgeniy , Akhmatkhanov Andrey , Slautin Boris , Tronche Hervé , Doutre Florent , Lunghi Tommaso , Baldi Pascal , Shur Vladimir
Published: September 2023

The paper presents the results of an experimental study of the local polarization reversal and creation of domains by a biased tip of scanning probe microscope (SPM) in lithium niobate single crystals of congruent composition with a surface layer modified by soft proton exchange (SPE). The depth dependence of H[Formula: see text] ions concentration in the SPE-modified layer measured by confocal Raman microscopy demonstrates a sufficient composition gradient. The creation of isolated domains and stripe domain structures has been done by two switching modes: (1) point switching by field application in separated points and (2) line scanning switching by motion of the biased tip being in contact with the sample surface. For point switching for pulse durations less than 10[Formula: see text]s, the logarithmic dependence of the domain diameter on the pulse duration was observed. The change of the dependence to a linear one for pulse duration above 10[Formula: see text]s has been attributed to the transition from the stochastic step generation at the domain wall to the deterministic one at the domain vertexes. The periodical structure of stripe domains was created in SPE CLN planar waveguides by scanning at elevated temperature. The revealed switching regime suppresses electrostatic interaction of neighboring domains and leads to a significant improvement of the domain structure regularity. The creation of the stable periodical domain structure with submicron periods in SPE CLN planar waveguides was demonstrated.
A Cloud Detection Method for Landsat 8 Satellite Remote Sensing Images Based on Improved CDNet Model
Authors: Qiu Junping , Cheng Peng , Cai Chenxiao
Published: September 2023

Cloud detection in remote sensing images is a crucial task in various applications, such as meteorological disaster prediction and earth resource exploration, which require accurate cloud identification. This work proposes a cloud detection model based on the Cloud Detection neural Network (CDNet), incorporating a fusion mechanism of channel and spatial attention. Depthwise separable convolution is adopted to achieve a lightweight network model and enhance the efficiency of network training and detection. In addition, the Convolutional Block Attention Module (CBAM) is integrated into the network to train the cloud detection model with attention features in channel and spatial dimensions. Experiments were conducted on Landsat 8 imagery to validate the proposed improved CDNet. Averaged over all testing images, the overall accuracy (OA), mean Pixel Accuracy (mPA), Kappa coefficient and Mean Intersection over Union (MIoU) of improved CDNet were 96.38%, 81.18%, 96.05%, and 84.69%, respectively. Those results were better than the original CDNet and DeeplabV3+. Experiment results show that the improved CDNet is effective and robust for cloud detection in remote sensing images.
A Comprehensive Model for Efficient Design Space Exploration of Imprecise Computational Blocks
Authors: Javadi Mohammad Haji Seyed , Faryabi Mohsen , Mahdiani Hamid Reza
Published: September 2023

After almost a decade of research, development of more efficient imprecise computational blocks is still a major concern in imprecise computing domain. There are many instances of the introduced imprecise components of different types, while their main difference is that they propose different precision-cost-performance trade-offs. In this paper, a novel comprehensive model for the imprecise components is introduced, which can be exploited to cover a wide range of precision-cost-performance trade-offs, for different types of imprecise components. The model helps to find the suitable imprecise component based on any desired error criterion. Therefore, the most significant advantage of the proposed model is that it can be simply exploited for design space exploration of different imprecise components to extract the suitable components, with the desired precision-cost-performance trade-off for any specific application. To demonstrate the efficiency of the proposed model, two novel families of Lowest-cost Imprecise Adders (LIAs) and Lowest-cost Imprecise Multipliers (LIMs) are introduced in the paper, which are systematically extracted based on exploration of the design space provided by the proposed model. A wide range of simulation and synthesis results are also presented in the paper to prove the comparable efficiency of the systematically extracted LIA/LIM structures with respect to the most efficient existing human-made imprecise components both individually and in a Multiply-Accumulate application.
(Invited) Al-Al Waferbonding Process Development for Heterogeneous Integration
Authors: Schulze Sebastian , Wietstruck Matthias , Voß Thomas , Krüger Patrick
Published: September 2023

This paper presents a surface-activated Al-Al wafer bonding process for patterned 200 mm wafers that removes the native oxide in an argon plasma and enables high bond quality with accurate alignment at temperatures below 300 °C. The study focuses on various factors that influence the final Al-Al bond in terms of contact resistance and shear strength. In addition to temperature, force and time during the actual bonding process, these include steps during the wafer fabrication that affect the Al bonding pads and the wafer bow. Furthermore, the impact of a post-bond cleaning process on the final bond result is analyzed. This work shows a low temperature Al-Al bonding process with high yield >90%, excellent bond strength >150 MPa and contact resistances in the mΩ range.
Epi Source-Drain Damage Mitigation During Channel Release of Stacked Nanosheet Gate-All-Around Transistors
Authors: Durfee Curtis , Otto IV Ivo , Kal Subhadeep , Pancharatnam Shanti , Flaugh Matthew , Kanaki Toshiki , Rednor Matthew , Zhou Huimei , Qin Liqiao , Meli Luciana , Loubet Nicolas , Biolsi Peter , Felix Nelson
Published: September 2023

Nanosheet gate-all-around devices have demonstrated several advantages in device performance and area scaling over finFET devices with higher device density and improved electrostatic control. Robust inner spacer (IS) and channel formation is critical for high performance, reduced variability and good yield. An isotropic dry etch of the sacrificial SiGe layer with extremely high selectivity to gate spacer, IS and Si channels is necessary for high-quality channel formation over a wide range of sheet widths. Furthermore, the nFET Si:P and pFET SiGe:B source-drain (S/D) epitaxy must be isolated using inner spacers or buffers to prevent damage during Channel Release (CR). The damage can be further mitigated with optimized CR etch chemistry, enabling IS scaling. We highlight S/D damage mechanisms during CR, then demonstrate reduced S/D damage by co-optimization of the IS, CR chemistry and S/D epitaxy.
SAB-Enabled Room Temperature Hybrid Bonding
Authors: Renaud Pablo , Abadie Karine , Fournel Frank , Dubarry Christophe , Baudin Floriane , Tauzin Aurelie
Published: September 2023

On the one hand, direct hybrid bonding is foreseen to revolutionize semiconductor device integration, allowing the seamless 3D interconnection of diverse materials with distinct properties. On the other hand, Surface Activation Bonding (SAB) is a powerful technique within the field of low-temperature bonding, offering enhanced bonding strength and compatibility with a wide range of materials. By dealing with the possibilities of SAB, this paper demonstrates the possibility of realizing a Cu-oxide direct hybrid bonding with a 5 µm pitch interconnections at ambient temperature. This success highlights the potential of SAB as a critical enabler for low-temperature hybrid bonding and its potential impact on next-generation semiconductor devices.
(Invited) Modified SAB Methods for Hybrid and All-Cu Bonding for 3D Integration below 200ºC
Authors: Suga Tadatomo , Otsuka Kanji
Published: September 2023

Two Surface Activated Bonding (SAB) methods will be proposed to enable low-temperature hybrid bonding for 3D integration. A modified one involves surface activation processes using Ar fast-atom-beam bombardment with simultaneous co-sputtering of Si nano-adhesion layer, followed by sequential plasma irradiation with N2 radicals. In the other one, we will connect two device wafers not in a hybrid but all-Cu bonding. A small insulation area surrounds the Cu pads on the wafer, while the rest is covered with Cu solid layers. These solid layers constitute the ground plane, power plane, or their paired layers and may contribute to heat dissipation when connected to thermal vias. The two wafers are connected only by bonding on the Cu electrodes and solid layers. Cu-Cu direct bonding is possible at room temperature by applying the standard SAB directly. Room-temperature bonding is overwhelmingly advantageous for bonding heterogeneous devices and wafers.
Investigation of Anodic Bond Formation Process and Potential Use of the Results
Authors: Knechtel Roy , Wenig Micaela , Seyring Martin , Kley Dominik
Published: September 2023

Anodic bonding of glass to silicon wafers is an essential step in microsystems manufacturing, combining reliable process setup with robust process control and providing very strong and hermetic wafer bonds. It is general accepted that the bond formation is based on anodic oxidation processes, but it is still under debate where the oxygen originates from and how far the oxidation can be driven. The oxidation mechanism during anodic bonding has been studied using sequential and one-step bonding procedures. It can be concluded that the oxygen for the oxidation originates from the glass. It is therefore possible to completely oxidise sputtered aluminium between two glass wafers during bonding, resulting in a nearly optically transparent bond of both wafers. By understanding the oxidation processes, it is possible to predict which surface layers will bond well (silicon, silicon dioxide, aluminium) and which will be hardly or impossible to bond (silicon nitride, gold). These predictions have been tested and confirmed by experimental results.
Efficient Xe Filling of MEMS Vapor Cells Empowered by Customized Triple Stack Wafer Bond Processing
Authors: Roshanghias Ali , Kaczynski Jaroslaw , Rodrigues Augusto , Hübner Martina , Zauner Markus , Grosso Giovanna , Andrianov Nikolai , Khan Muhammad , Grömer Thomas , Fuchs Tino , Binder Alfred
Published: September 2023

Nuclear-magnetic-resonance (NMR) gyroscopes based on MEMS vapor cell technology are currently being investigated worldwide and show superior advantages over current MEMS gyroscopes. However, there are still challenges in the upscaling and further deployment of NMR gyroscopes, due to the extremely high cost of the required gases (i.e., 129Xe, 131Xe), size, and high power consumption. To tackle these bottlenecks, in this study, a miniaturized, chip-scale, and low-cost NMR gyroscope has been conceptualized and fabricated. Here, a cost-effective and scalable filling of MEMS vapor cells with Xe gas was developed via an innovative microfabrication and wafer stacking process flow. By utilizing ultra-thin glass wafers, Taiko-processed silicon wafers, and an external gas flow system integrated into the wafer bonder, a sequential anodic bonding technique is executed to create a hermetically sealed Xe gas-filled chamber at minimal Xe consumption during the filling process.
Illuminating Oxygen Reduction Reaction Kinetics in High Temperature Polymer Electrolyte Membrane Fuel Cells Using EIS
Authors: Giotakos Panagiotis I. , Neophytides Stylianos G.
Published: September 2023

High Temperature Polymer Electrolyte Membrane Fuel Cells (HTPEMFCs) commercialization, is impeded by the sluggish, power intensive and elusive cathodic Oxygen Reduction Reaction (ORR) kinetics. In this work we provide solid experimental evidence that the simple three elementary step Dissociative Adsorption (DA) pathway, with two intermediate species (Oad and OHad), can accurately describe the steady state (IV) and the Electrochemical Impedance Spectra (EIS) response of a HTPEMFC. Deconvoluted EIS outlined the important role of Intrinsic Kinetic Inertia, which dominated both EIS and polarization resistance. The Degree of Rate Control (DRC) analysis, identified the O2(g) dissociative adsorption as the rate limiting step. Finally, Transition State Theory (TST) allowed the extraction and analysis of ORR energetics, demonstrating that the high ORR overpotential losses originate from the combined strength of both kinetically and thermodynamically imposed barriers, due to the high bonding strength of Oad on Pt and the high activation energy of O2(g) adsorption.
Efficient High Temperature PEMFC Metallic Stack
Authors: Neofytidis Charalampos , Paloukis Fotios , Athanasopoulos Nikolaos , Neophytides Stylianos G. , Daletou Maria
Published: September 2023

The benefit of high temperature (HT) polymer electrolyte membrane fuel cells (PEMFCs) is very high for high power applications. They can be used in stationary and portable power devices combining the advantages of the PEM type cells (flexibility in dynamic operation, compactness) and high temperature operation (elimination of fuel humidification and carbon monoxide clean up). This work focuses on the development, construction and testing of an efficient all-metallic HT-PEMFC stack with 1kWe power output. The proper polymer electrolytes selection has given the possibility of operating the stack within the range of 160-190oC. The Membrane-Electrode-Assemblies (MEAs) and all of the stack’s components were designed and prepared in-house. There are many parameters that affect the fuel cell stack characteristics and performance such as the materials, components’ design and proper assembly of the stack, as well as the operating conditions. The electrical efficiency of the stack was 50% with power output of 1070 W and a power density of about 0.18 W/cm2 at 180°C under the feed of pure H2. With reformate hydrogen feeds, the stack reached the same performance.
Modeling of Proton Exchange Membrane Fuel Cell Stack and Start Strategy Optimization with a Multi-Objective Genetic Algorithm
Authors: Liu Zhao , Chen Hui Cui , Zhang Tong , Unwerth Thomas von , Meuser Carmen
Published: September 2023

This paper proposes a non-dominated sorting genetic algorithm II (NSGA-II) for optimizing the startup strategy of a proton exchange membrane fuel cell (PEMFC) stack to improve the dynamic response capability, output voltage, and net power. First, a Simulink model of the PEMFC stack including the anode module, cathode module, water transfer module, output voltage module, and output net power module is established, and the accuracy of the stack model is verified through experiments. The three performances are then optimized simultaneously based on NSGA-II. The results show that the optimized start-up loading strategy results in a PEMFC stack that outperforms the base model in steady-state voltage, undershoot percent, and net power these three indicators with the same response time, demonstrating the success of the method in solving multiple optimization problems. This study presents an effective approach for the multi-objective optimization of the PEMFC stack, which is of guidance for engineering practice.
Non-PGM Cathode Electrocatalysts for PEM Fuel Cells
Authors: Charalampopoulos Georgios , Maniatis Ilias , Daletou Maria
Published: September 2023

The replacement of unsustainable noble-metal catalysts with platinum group metal (PGM)-free catalysts for oxygen reduction reaction (ORR) is essential for material wise and market value viable PEMFCs. Despite the tremendous efforts involved in their development, many drawbacks persist that include poor design of the architecture and chemical composition, control over the synthesis and poor stability, which seriously degrades their performance. These challenges are universally recognized and lead to a strong focus on designing alternative catalysts. Among the investigated candidates, Me–N-C catalysts are the most promising. In this work, the synthesis, characterization and evaluation of several Fe–N–C materials are presented. The synthetic approach involves templating using silicon-based materials. Structural, physicochemical, and electrochemical characterization in terms of ORR activity is also performed.
Pt-Ta-Co Electrocatalysts for Polymer Electrolyte Fuel Cells
Authors: Miyamoto Ryo , Ogawa Taichi , Nishiizumi Ryosuke , Yasutake Masahiro , Noda Zhiyun , Nishihara Masamichi , Hayashi Akari , Matsuda Junko , Sasaki Kazunari
Published: September 2023

Polymer electrolyte fuel cells for heavy-duty applications require highly active and durable electrocatalysts. Our research group has developed electrocatalysts with Pt-Ta-Co-based alloy. This study evaluates the cell performance with the Pt-Ta-Co-based alloy catalysts by varying the fabrication conditions of the electrocatalyst layers, such as the ionomer and solid ratio of the electrocatalyst paste. In addition, the effect of the carbon catalyst support on the cell performance is evaluated using mesoporous carbon and typical Ketjen black carbon supports. The cells using these new catalysts exhibited comparable performance as the cell using a typical Pt/KB catalyst.
Investigation of the Impact of Chloride Contamination on Degradation in PEM Water Electrolyzer Cells
Authors: Kuhnert Eveline , Kiziltan Ozge , Hacker Viktor , Bodner Merit
Published: September 2023

PEM water electrolysis (PEMWE) is a promising technology for hydrogen production from renewable energy sources. However, the quality of feed water significantly impacts performance and durability of PEMWE, and cost-intensive purification steps are required to reach a water resistivity of >18.2 MΩ*cm. To omit scarcity of groundwater, one major aim is to use alternative water sources, such as feed water generated by the desalination of seawater. After the desalination process, seawater still contains low amounts of ionic contaminants. In this study, the effect of Cl− contaminants on the performance of a PEMWE single cell was tested with an accelerated stress test. After 50 h of operation, a 23% increase in the cell voltage was observed and Cl− adsorption and catalyst detachment on the electrodes were detected. The fluoride emission rate (FER), as indicator for membrane degradation, was found to be 4-fold higher for the cell exposed to the Cl− contaminant.
(Digital Presentation) Facile Fabrication of Nickel and Sc-Doped Zirconia Cermet Electrode Thin Film on YSZ Substrate Via Screen-Printing for Solid Oxide Electrochemical Cells
Authors: Macalisang Christine Mae , Cervera Rinlee
Published: September 2023

Electrode materials play a key role in the performance of solid oxide electrochemical cells. In this study, screen-printing was used to fabricate a porous nickel – scandia-stabilized zirconia (Ni-ScSZ) cermet electrode on a dense YSZ solid electrolyte substrate. The effect of sintering temperatures, 1200°C and 1300°C, on the structure and morphology of the deposited films were investigated. The screen-printed films were sintered and then reduced under an Ar/5% H2 gas environment at 700°C for 2h to form porous electrodes. The sintered films exhibited NiO and ScSZ cubic phases from X-ray diffraction (XRD) analysis. A desired porous morphology of NiO-ScSZ film sintered at 1200°C was achieved compared to a denser morphology sintered at 1300°C as revealed by the scanning electron microscopy (SEM) micrographs. XRD patterns of reduced samples suggested a complete reduction of cubic NiO to Ni with an increase in porosity as observed from SEM micrographs.
(Digital Only Presentation) Effects of Ink Solvent on the Screen-Printing Fabrication and Morphology of LSM-YSZ Thin Films Deposited on YSZ Substrate for Solid Oxide Electrochemical Cells
Authors: Hablado Jessa , Cervera Rinlee
Published: September 2023

Screen-printing is a cheap and easy thin film deposition technique utilized in energy devices fabrication, specifically, in solid oxide electrochemical cells (SOCs). In this study, LSM-YSZ, a promising component material for SOCs application was deposited on YSZ electrolyte via screen-printing. Specifically, the study aimed to investigate the effect of the solvent used in screen-printing and the effect of varying ink formulation on the quality of the deposited film. LSM-YSZ precursor powders synthesized via glycine-nitrate combustion process (GNP) were screen-printed on YSZ substrate using ethanol and alpha-terpineol solvents. The structure and morphology of LSM-YSZ thin films using two solvents were compared. Results showed that both solvents produced a rhombohedral LSM and cubic YSZ thin films and the use of a-terpineol solvent with higher solid content produced a desired uniform and porous morphology with homogenous pore distribution as revealed by XRD and SEM morphological results.
Cycle Characterization of SiO-Based Lithium-Ion-Batteries Using Real Load Profiles
Authors: Moyassari Erfan , Li Zheng , Tepe Benedikt , Streck Luiza , Jossen Andreas
Published: September 2023

Understanding the cyclic behavior of Lithium-Ion Batteries (LIBs) is crucial for optimizing their performance and extending their operational lifespan. This work presents a study on the cycle characterization of silicon-oxide-based (SiOx) cells, focusing on the impact of real load profiles and state-of-charge (SoC) ranges while varying the SiOx content in the cells. Various load profiles representing real usage patterns obtained from an industrial partner were applied to SiO-based pouch cells. These load profiles are represented over different SoC ranges to explore the effect of varying levels of charge/discharge on battery aging. The aging characteristics of the batteries are evaluated by monitoring capacity fade, state-of-health (SoH), and capacity end-point-slippage. The experimental results demonstrate that the different SiOx content of the investigated cells and the SoC range significantly influence the cycle behavior of the cells. The resulting capacity loss was affected especially by the anode overhang effect. Cycling under high SoC conditions accelerates capacity fade and leads to higher SoH loss. The findings also indicate that SiO-based cells exhibited higher aging than traditional graphite-based cells. The capacity fade rate increased at higher SiOx content.
Intensive Care Managers’ Experiences of the COVID-19 Pandemic: A Dramatic Change of the Intensive Care Landscape
Authors: Nordin Anna , Engström Åsa , Andersson Maria , Fredholm Angelica
Published: September 2023

Aim. To describe intensive care managers’ experiences of premises and resources of care in intensive care units during the COVID-19 pandemic. Background. Intensive care units (ICUs) were enormously pressured during the COVID-19 pandemic from many ill patients, requiring advanced care. Hospital and community volunteers increased staff strength. Obligatorily, recruitments were also conducted using transfer of staff from different hospital departments. However, there is little knowledge about intensive care managers’ (ICMs) experiences of leadership during the COVID-19 pandemic. Methods. A qualitative descriptive study was conducted from March to April 2022. Semistructured interviews were held with 12 ICMs who were purposively sampled from the ICU in ten Swedish hospitals. Data were analysed using qualitative content analysis. Results. Two themes emerged: a dramatic change of the intensive care landscape and we could handle more than we thought, but at a steep price. Participants described that the ICUs had to perform extraordinary changes at a very fast pace, which initially created a sense of cohesion. Training and introduction to war-like conditions associated with uncertainty meant that ICMs had to support ICU staff in prioritising interventions. Participants described how ICUs stood strong against a pandemic, but stress, worries, and anxiety took a heavy toll on ICU staff and ICMs. The pandemic eroded the resilience in ICUs. Participants described a deterioration in health and said that sick leaves and resignations occurred. Conclusion. Our findings show ICMs’ experiences as a field of tension between resources and demands, whereby the changes created a heavy burden that left intensive care weakened. Implications for Nursing Management. Findings emphasised the importance of creating working conditions using human resources and materials in order to rebuild resilience in intensive care with the ability to conduct safe patient care.
Decision-Making Based on Predictive Process Monitoring of Patient Treatment Processes: A Case Study of Emergency Patients
Authors: Aravazhi Agaraoli , Helgheim Berit I. , Aadahl Petter
Published: September 2023

This paper investigates predictive process monitoring problems in emergency treatment by combining the fields of process management and artificial intelligence. The objective is to predict the next activity and its timestamp in the treatment of emergency patients who have undergone surgery at the gastroenterology or urology surgery units in a hospital in Norway. To achieve this goal, three models were developed using different algorithms, and the best performing model was identified using various performance metrics. The results demonstrate the potential of predictive process monitoring to accurately forecast the outcome of patient treatments. By leveraging the insights gained from predictive process monitoring, hospitals can make more informed decisions. The findings of this study suggest that predictive process monitoring holds significant promise as a tool for improving the efficiency and effectiveness of emergency patient treatment processes. This research has significant implications for the field of decision sciences, particularly regarding resource allocation, reducing waiting times, and improving patient outcomes. The ability to predict the outcomes of patient treatment processes has important implications for hospitals, allowing the streamlining and acceleration of the treatment process. Overall, this study provides a promising framework for predicting patient treatment processes by using the predictive process monitoring method. This could be expanded upon in future research, ultimately leading to improved patient outcomes and better decision-making in healthcare.