bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finite element simulation and experiment of residual stress evolution in MEMS structures
Authors: Wen Xiao , Chen Jinchuan , Huang Qinwen , Guo Huihui 
Published: April 2024

Abstract
The MEMS device structure is usually formed by the combination of thick film and thin film deposition of many different materials, and the residual stress generated in the process of integration/superposition of different materials has a significant impact on the performance and reliability of the device.In this study, a test structure of a multilayer thin film was designed and processed. Based on this, finite element modeling analysis and reliability experiment, analyze the evolution of residual stress and construct the corresponding theoretical analysis model. The finite element modeling analysis can characterize the evolution and distribution laws of residual stress. The reliability experiment is mainly by carrying out the temperature shock experiment, and measuring the resistance value, resonance frequency and the surface morphology of the device, so as to better reflect the change of residual stress. Through this study, the resonant frequency and surface morphology of the device can reflect the residual stress of the device, which provides help for the test and analysis of the residual stress. To a certain extent, it can help reduce the harm caused by the residual stress in the design and manufacturing process, and improve the performance and reliability of MEMS devices.
A low-noise, radiation-hardened charge-sensitive amplifier for Silicon carbide neutron detector
Authors: Liu X. , Liu Y. , Fang S. , Wang Y. 
Published: April 2024

Abstract
Silicon carbide(SiC) neutron detectors can be applied to extreme environments with high temperature and strong radiation. The total noise factor is most significantly influenced by the noise factor of the first stage in a cascade amplifier. Hence, the preamplifier must exhibit exceptional noise performance. The readout circuit is inevitably exposed to the influence of radiation, which may result in temporary or even permanent failure of electronic systems. The connection method between the SiC neutron detector and the readout circuit is typically DC-coupled. When the sensor is working, the leakage current generated by the sensor will enter the input end of the CSA and change the baseline position of the CSA. In this paper, a low-noise CSA with leakage current compensation circuit(LCC) is presented. The circuit’s voltage-to-charge amplification is 2.98mV/fC, and the error due to nonlinearity is below 0.01%. Without considering the input parasitic capacitance, ENC is 43.12e-. In addition, the circuit also has good radiation resistance and leakage current compensation function. It is implemented and simulated in the DB Hitek 0.18μm CMOS process model.
A silicon resonant pressure sensor based on thermal stresses matched structures
Authors: Yu Hengshu , Wang Junbo , Lu Yulan , Xie Bo , Shang Yanlong , Liu Zhao 
Published: April 2024

Abstract
This paper introduced a silicon resonant pressure sensor based on thermal stress-matched structures to extend the operating temperature range. The sensor designed this time consists of an SOI wafer with a pressure-sensitive diaphragm for pressure sensing and two integrated resonators, a silicon wafer for vacuum packaging, and a glass wafer for additional stress isolation. The multilayer structures were bonded together to form a thermal stress-matched part to address the problem of temperature inflection points of conventional resonant pressure sensors within broad temperature zones. Finite element analyses optimized the sensor’s pressure- and temperature-sensitive characteristics. Micromachining based on eutectic and anodic bonding to fabricate sensor chips. Characterization results indicated the developed pressure sensor can work stably in a wide temperature range of -55∼125°C and has excellent fitting accuracy exceeding ±0.01% FS., which showed a better performance than previously reported counterparts.
Aluminum Nitride Thin Film Pyroelectric Detector Based on Metamaterial Absorber
Authors: Zhang Congchun , Zhao Yongmin , Han Yulu , Ci Guangteng , Yin Lumeng , Zhao Xiaoguang , Ming Anjie , Wei Feng , Mao Changhui 
Published: April 2024

Abstract
Highly integrated pyroelectric detectors have been widely used in infrared spectrometers and gas detection. Aluminum nitride(AlN) has excellent compatibility with CMOS processes and is often used to fabricate piezoelectric and optoelectronic devices with superior performance. This study proposes a pyroelectric detector with AlN thin film as the sensitive element and integrated metamaterial absorber. Magnetron sputtering technology was used to prepare the AlN thin film as the sensitive element. To achieve narrowband specific absorption subsequently, a three-layer metamaterial absorber structure was designed and simulated. Preliminary processing of AlN pyroelectric detectors was performed based on MEMS technology. The designed narrowband absorbing structure exhibits near unity specific absorption, with a quality factor of 17.75. This study preliminarily verifies the application potential of AlN thin films in mid-infrared pyroelectric sensors, and realizes narrowband absorption through metamaterial structures, laying the foundation for the development of mid-infrared gas detection sensors.
Microfluidic enabled flexible sensors based on self-diffusion MWCNTs dispersion
Authors: Li Yuzhen , Qian Xiang 
Published: April 2024

Abstract
Flexible microfluidic pressure sensors have recently attracted a lot of attention due to its revolutionary potential in the field of healthcare. These sensors provide non-invasive, highly sensitive, and adaptable options for tracking various aspects of human movement and health. Nevertheless, there are a number of limitations that affect the effectiveness of microfluidic pressure sensors, including material selection, sensor packaging techniques, sensitivity, and stability. The research outlined in this paper, which aims to address these issues head-on and significantly improve the functionality of microfluidic pressure sensors in order to increase their usefulness in the fields of medical and biomedical applications.
A novel self-powered sensitive porous ZnO NWs/PDMS sponge capacitive pressure sensor
Authors: Liu Xinyue , He Mengfan , Djoulde Aristide , Wang Zhiming , Liu Mei 
Published: April 2024

Abstract
The demand for flexible sensors has increased due to the explosive expansion of flexible electronic applications, but there are concerns that the development of high-precision measurement is limited. Capacitive pressure sensors are extensively utilized among diverse sensors due to their simple structure, high resolution, and outstanding dynamic response characteristics. Therefore, by sandwiching a porous ZnO NWs PDMS (PZP) sponge dielectric layer between two ITO/PET electrodes, a flexible capacitive pressure sensor with high sensitivity, short response time, and wide working range was prepared. The porous PDMS sponge was prepared utilizing the salt particle as a template, then ZnO NWs in different precise proportions were added to it. The sensitivity of PZP sponge capacitive pressure sensors with different salt particle sizes and ZnO NWs dosages were compared. The research results indicate that when salt particle sizes less than 150 μm, and the amount of ZnO NWs in PZP sponge is increased to 200 mg, the sensor sensitivity is highest in the pressure range of 2.5-7.5 kPa, reaching 0.1279 kPa-1, response time less than 70 ms. When the PZP sponge sensor is used as a self-powered source, it achieves the best output of 1.2 V and 6.8 nA at 5.74 kPa pressure. It provides a new way to tackle the challenge of low sensitivity of flexible sensors to capacitive signal and lays a foundation for expanding the application scenarios of ZnO NWs.
Design and Fabrication of Quartz MEMS Based Double-ended Tuning Fork Resonator
Authors: Bi X. , Ma Y. , Wang X. , Hua X. , Liu Y. , Sun S. 
Published: April 2024

Abstract
This paper presents the design and fabrication of double-ended tuning fork (DETF) resonator based on quartz. DETF resonator was designed with two tines structure, due to this configuration has the advantage of providing dynamic balance. Both surface and side electrode were designed on DETF tines in order to enhance the piezoelectric effect. DETF resonator was fabricated from a quartz substrate by chemical wet etching and photolithography processes, the key feature of fabrication is to create Cr/Au metal films, which should be strong enough to withstand the aggressive quartz etchant, meanwhile, the wet etching parameters was optimized in order to reduce the sidewall structure in +X orientation which can greatly deteriorate vibrating characteristics of DETF tines. Experimental results demonstrated that the Q value would be lowered and motional resistance be increased with the force sensitivity increase of DETF tines.
Leaf unfolding and lamina biomechanics in Syngonium podophyllum and Pilea peperomioides
Authors: Modert Michelle , Speck Thomas , Masselter Tom 
Published: April 2024

Abstract
In nature, leaves and their laminae vary in shape, appearance and unfolding behaviour. We investigated peltate leaves of two model species with peltate leaves and highly different morphology (Syngonium podophyllum and Pilea peperomioides) and two distinct unfolding patterns via time-lapse recordings: we observed successive unfolding of leaf halves in S. podophyllum and simultaneous unfolding in P. peperomioides. Furthermore, we gathered relevant morphological and biomechanical data in juvenile (unfolding) and adult (fully unfolded) leaves of both species by measuring the thickness and the tensile modulus of both lamina and veins as a measure of their stiffness. In S. podophyllum, lamina and veins stiffen after unfolding, which may facilitate unfolding in the less stiff juvenile lamina. Secondary venation highly contributes to stiffness in the adult lamina of S. podophyllum, while the lamina itself withstands tensile loads best in direction parallel to secondary veins. In contrast, the leaf of P. peperomioides has a higher lamina thickness and small, non-prominent venation and is equally stiff in every region and direction, although, as is the case in S. podophyllum, thickness and stiffness increase during ontogeny of leaves from juvenile to adult. It could be shown that (changes in) lamina thickness and stiffness can be well correlated with the unfolding processes of both model plants, so that we conclude that functional lamina morphology in juvenile and adult leaf stages and the ontogenetic transition while unfolding is highly dependent on biomechanical characteristics, though other factors are also taken into consideration and discussed.
Catchment-scale thawing and greening decreases long-term nitrogen export in NE Greenland
Authors: Speir Shannon L , Tank Jennifer L , Pastor Ada , Muller Marc F , Mastepanov Mikhail , Riis Tenna 
Published: April 2024

Abstract
Climate change is expected to alter nitrogen (N) export from Arctic rivers, with potential implications for fragile coastal ecosystems and fisheries. Yet, the directionality of change is poorly understood, as increased mobilization of N in a ‘thawing’ Arctic is countered by higher rates of vegetative uptake in a ‘greening’ Arctic, particularly in the understudied region of Greenland. We use an unprecedented dataset of long-term (n = 18 years) river chemistry, streamflow, and catchment-scale changes in snow and vegetation to document changing riverine N loss in Greenland. We documented decreasing inorganic and organic N loads, linked to decreasing snow stores, warming soils, and enhanced plant uptake. Higher variability in N export across years also points to the increasing role of high flow events in driving downstream N loss. This alteration in N cycling may significantly reduce both inorganic and organic N transport across the terrestrial-aquatic boundary during the open water season in a rapidly warming Greenland.
Investigation of tribological behavior of coated and untreated rail steels under wet conditions
Authors: Cetin M Huseyin , Kondul Bilgehan 
Published: April 2024

Abstract
Rails are exposed to more stresses, especially in the regions of narrow radius curves and switch passages. Therefore, the tribological features of these regions are important. In this study, the effect of boronization on tribological properties was examined. For this purpose, experiments were carried out on samples boronized at 800 °C for 2 h and 8 h and on untreated samples. With these experiments, the friction coefficient, volume loss and surface roughness values of the samples under wet conditions were examined. In addition, the microstructures of the material after boriding were observed by SEM and EDX. The variance and regression method (ANOVA) was used for the statistical analysis of the experimental results. After SEM examinations, a coating layer of ∼22 μm (FeB) and ∼48 μm (FeB+Fe2B) were obtained on the surface of the rail steels boronized for 2 and 8 h, respectively. The microhardness of the rail steels, which was ∼300 HV for the untreated sample, increased to ∼1900 HV and ∼2400 HV with the boronizing process boronized for 2 and 8 h, respectively. According to the ANOVA results, the effects of the boronizing process on the decrease of the friction coefficient and the volume loss were calculated as 42% and 46%, respectively. Finally, according to the corrosion results, the corrosion resistance of the boronized rail steels decreased with the boride layer formed.
Information flow in parameterized quantum circuits
Authors: Anand Abhinav , Bjørn Kristensen Lasse , Frohnert Felix , Sim Sukin , Aspuru-Guzik Alán 
Published: April 2024

Abstract
In this work, we introduce a new way to quantify information flow in quantum systems, especially for parameterized quantum circuits (PQCs). We use a graph representation of the circuits and propose a new distance metric using the mutual information between gate nodes. We then present an optimization procedure for variational algorithms using paths based on the distance measure. We explore the features of the algorithm by means of the variational quantum eigensolver, in which we compute the ground state energies of the Heisenberg model. In addition, we employ the method to solve a binary classification problem using variational quantum classification. From numerical simulations, we show that our method can be successfully used for optimizing the PQCs primarily used in near-term algorithms. We further note that information-flow based paths can be used to improve convergence of existing stochastic gradient based methods.
Unique correlation between electrical, structural properties and electromagnetic shielding properties of carbon nanotube sheets
Authors: Choi Minseouk , Cho Young Shik , Park Kyung Tae , Lee Kyunbae , Shin Keun-Young , Jung Yeonsu , Kim Taehoon 
Published: April 2024

Abstract
Correlation between electrical, structural properties and electromagnetic shielding efficiency (EMI SE) of carbon nanotube sheets (CNTSs) was investigated. Solvent densification of CNTSs led to enhancements of carbon nanotube (CNT) bundling behavior and densification in the thickness direction while maintaining the areal density of the CNTSs. These structural modifications resulted in enhanced electrical properties and reduced sheet thickness by modifying the microstructure and bundling characteristics. Remarkably, contrary to conventional EMI shielding materials, the sheet resistance which reflects bundling behavior and microstructure of CNTSs, is the critical factor affecting the EMI SE of the CNTSs rather than electrical conductivity. The findings provide fundamental insights essential for the design of EMI shielding films incorporating CNTs.
Validating a data-driven framework for vehicular traffic modeling
Authors: Lane Daniel , Roy Subhradeep 
Published: April 2024

Abstract
This study presents a data-driven framework for modeling complex systems, with a specific emphasis on traffic modeling. Traditional methods in traffic modeling often rely on assumptions regarding vehicle interactions. Our approach comprises two steps: first, utilizing information- theoretic (IT) tools to identify interaction directions and candidate variables thus eliminating assumptions, and second, employing the sparse identification of nonlinear systems (SINDy) tool to establish functional relationships. We validate the framework’s efficacy using synthetic data from two distinct traffic models, while considering measurement noise. Results show that IT tools can reliably detect directions of interaction as well as instances of no interaction. SINDy proves instrumental in creating precise functional relationships and determining coefficients in tested models. The innovation of our framework lies in its ability to use data-driven approach to model traffic dynamics without relying on assumptions, thus offering applications in various complex systems beyond traffic.
Random feedback alignment algorithms to train neural networks: why do they align?
Authors: Chu Dominique , Bacho Florian 
Published: April 2024

Abstract
Feedback alignment algorithms are an alternative to backpropagation to train neural networks, whereby some of the partial derivatives that are required to compute the gradient are replaced by random terms. This essentially transforms the update rule into a random walk in weight space. Surprisingly, learning still works with those algorithms, including training of deep neural networks. The performance of FA is generally attributed to an alignment of the update of the random walker with the true gradient—the eponymous gradient alignment—which drives an approximate gradient descent. The mechanism that leads to this alignment remains unclear, however. In this paper, we use mathematical reasoning and simulations to investigate gradient alignment. We observe that the feedback alignment update rule has fixed points, which correspond to extrema of the loss function. We show that gradient alignment is a stability criterion for those fixed points. It is only a necessary criterion for algorithm performance. Experimentally, we demonstrate that high levels of gradient alignment can lead to poor algorithm performance and that the alignment is not always driving the gradient descent.
Effects of medication management in geriatric patients who have fallen: results of the EMMA mixed-methods study
Authors: Clemens Stephanie , Iglseder Bernhard , Alzner Reinhard , Kogler Magdalena , Rose Olaf , Kutschar Patrick , Krutter Simon , Kanduth Karin , Dückelmann Christina , Flamm Maria , Pachmayr Johanna 
Published: April 2024

Abstract

Background
comprehensive medication management (CMM) can reduce medication-related risks of falling. However, knowledge about inter-individual treatment effects and patient-related barriers remains scarce.

Objective
to gain in-depth insights into how geriatric patients who have fallen view their medication-related risks of falling and to identify effects and barriers of a CMM in preventing falls.

Design
complementary mixed-methods pre–post study, based on an embedded quasi-experimental model.

Setting
geriatric fracture centre.

Methods
qualitative, semi-structured interviews framed the CMM intervention, including a follow-up period of 12 weeks. Interviews explored themes of falling, medication-related risks, post-discharge acceptability and sustainability of interventions using qualitative content analysis. Optimisation of pharmacotherapy was assessed via changes in the weighted and summated Medication Appropriateness Index (MAI) score, number of fall-risk-increasing drugs (FRID) and potentially inappropriate medications (PIM) according to the Fit fOR The Aged and PRISCUS lists using parametric testing.

Results
thirty community-dwelling patients aged ≥65 years, taking ≥5 drugs and admitted after an injurious fall were recruited. The MAI was significantly reduced, but number of FRID and PIM remained largely unchanged. Many patients were open to medication reduction/discontinuation, but expressed fear when it came to their personal medication. Psychosocial issues and pain increased the number of indications. Safe alternatives for FRID were frequently not available. Psychosocial burden of living alone, fear, lack of supportive care and insomnia increased after discharge.

Conclusion
as patients’ individual attitudes towards trauma and medication were not predictable, an individual and longitudinal CMM is required. A standardised approach is not helpful in this population.
Barriers and facilitators to early mobilisation and weight-bearing as tolerated after hip fracture surgery among older adults in Saudi Arabia: a qualitative study
Authors: Turabi Ruqayyah Y , Sheehan Katie J , Guerra Stefanny , O'Connell Matthew D L , Wyatt David 
Published: April 2024

Abstract

Objective
To explore the practice of prescribing and implementing early mobilisation and weight-bearing as tolerated after hip fracture surgery in older adults and identify barriers and facilitators to their implementation.

Methods
Semi-structured interviews were conducted with 20 healthcare providers (10 orthopaedic surgeons and 10 physiotherapists) from Saudi Arabian government hospitals. Data were analysed using inductive thematic analysis.

Results
While early mobilisation and weight-bearing as tolerated were viewed as important by most participants, they highlighted barriers to the implementation of these practices. Most participants advocated for mobility within 48 h of surgery, aligning with international guidance; however, the implementation of weight-bearing as tolerated was varied. Some participants stressed the type of surgery undertaken as a key factor in weight-bearing prescription. For others, local protocols or clinician preference was seen as most important, the latter partially influenced by where they were trained. Interdisciplinary collaboration between orthopaedic surgeons and physiotherapists was seen as a crucial part of postoperative care and weight-bearing. Patient and family member buy-in was also noted as a key factor, as fear of further injury can impact a patient’s adherence to weight-bearing prescriptions. Participants noted a lack of standardised postoperative protocols and the need for routine patient audits to better understand current practices and outcomes.

Conclusion
This study contributes to national and global discussions on the prescription of early mobilisation and weight-bearing as tolerated. It highlights the necessity for a harmonised approach, incorporating standardised, evidence-based protocols with patient-specific care, robust healthcare governance and routine audits and monitoring for quality assurance and better patient outcomes.
A report on the safety of acitretin use in patients with renal failure on haemodialysis
Authors: Shim Paul Jaehoon , Quintos Jessica Leigh , Faraz Khushnood , Smith Isabelle Taylor , Petty Amy Jiayue , Bottomley Matthew , Wheless Lee Emerson , Whitley Melodi Javid 
Published: April 2024

Abstract
Acitretin, commonly used for severe psoriasis and keratinocyte carcinoma chemoprevention in high-risk patients, is contraindicated in patients with end-stage renal disease (ESRD) on haemodialysis (HD). However, these patients often lack medication choices and in certain clinical scenarios the benefits of acitretin may outweigh the potential risks. We identified 24 patients with ESRD on HD undergoing acitretin treatment from the Duke and Vanderbilt University Medical Centers. While adverse effects were common, they were not a frequent cause of treatment discontinuation among patients. We also found no association between acitretin treatment and hospital admissions or mortality. Lastly, we found statistically significant increases in alkaline phosphatase (ALP; P = 0.03) and total bilirubin (P &lt; 0.001) when patients were receiving acitretin and HD compared with baseline. However, there was no dose dependency or temporal association with acitretin or HD initiation. Based on these preliminary findings, we find that acitretin may safely be used in patients receiving HD, with close monitoring of ALP and bilirubin.