bluuebunny/crossref_metadata_2025 huggingface dataset:
Astrophysical and relativistic modeling of the recoiling black hole candidate in quasar 3C 186
Authors: Boschini Matteo , Gerosa Davide , Salafia Om Sharan , Dotti Massimo
Published: April 2024

The compact object in quasar 3C 186 is one of the most promising recoiling black hole candidates, exhibiting both an astrometric displacement between the quasar and the host galaxy as well as a spectroscopic shift between broad and narrow lines. 3C 186 also presents a radio jet that, when projected onto the plane of the sky, appears to be perpendicular to the quasar-galaxy displacement. Assuming a gravitational-wave kick is indeed responsible for the properties of 3C 186 and using state-of-the-art relativistic modeling, we show that current observations allow for exquisite modeling of the recoiling black hole. Most notably, we find that the kick velocity and the black hole spin are almost collinear with the line of sight and the two former vectors appear perpendicular to each other only because of a strong projection effect. The targeted configuration requires substantial fine-tuning: while there is a region in the black hole binary parameter space that is compatible with 3C 186, the observed system appears to be a rare occurrence. Using archival radio observations, we explored different strategies that could potentially confirm or rule out our interpretation. In particular, we developed two observational tests that rely on the brightness ratio between the approaching and receding jet as well as the asymmetry of the jet lobes. While the available radio data provide loose constraints, deeper observations have the unique potential of unveiling the nature of 3C 186.
Addition of the Local Volume sample of galaxies from the FAST HI survey
Authors: Karachentsev Igor D. , Karachentseva Valentina E. , Kaisin Serafim S. , Zhang Chuan-Peng
Published: April 2024

We report the discovery of 20 new dwarf galaxies in the Local Volume identified as optical counterparts to the Five-hundred-meter Aperture Spherical radio Telescope (FAST) All Sky HI Survey (FASHI) sources. The galaxies have a median stellar mass of 7.8 × 106 M⊙ and a median HI mass of 1.0 × 107 M⊙. Most of them are field galaxies, while three are probable members of the M 101 and M 106 groups. We also found seven FASHI radio sources to be probable dark HI clouds in nearby groups. Together with four other known HI clouds in the local groups, their mean-square radial velocity difference of 49 km s−1 with respect to the host galaxies yields an average total mass of (2.7 ± 1.0)×1011 M⊙ for these groups on the projected scale of 90 kpc.
Hydrothermal pre-treatment of hospital food waste for efficient bio-methane generation
Authors: Isa Nadia , Md Huzir Nurhamieza , Rosly Muhammad Bukhari , Amin Azlan Nur Rasyid , Hussin Mohd Hidayat , Tamunaidu Pramila
Published: April 2024

Municipal solid waste management (MWM) in Malaysia has become a challenging task in recent years due to the growth of population, industrialization and an increase in quantity and variation in the types of waste generated. Major solid waste generated in Malaysia is organic waste which includes mainly food waste from households, food processing facilities, markets, food and beverages industry and hospitals. Therefore, it is crucial to identify ways to manage food waste (FW) properly and improve the energy recovery efficiency. This paper is aimed to study the impact of pre-treatment on food waste from Hospital Pakar Sultanah Fatimah (HPSF) as a method to decompose FW faster and to determine the potential of bio-methane generation. A compositional study showed that total solid waste generated was 2,301 kg with 67% waste from lunch followed by 31% from breakfast sessions daily. Hydrothermal pre-treatment was done using a Multipurpose Recycling Machine (MRM) at 1.6MPa for 15 minutes followed by anaerobic digestion with and without the inoculum addition. Un-treated FW with inoculum was used as control in this experiment. It was found out that at a controlled pH of 7, hydrothermal pre-treatment and addition of inoculum i.e. cow manure played an important role in anaerobic digestion process for enhancement of bio-methane production. It significantly reduced the lag phase by 4 days and produced biogas faster compared to nontreated FW and hence, increased the biogas volume up to 638.53 mL compared to 504.08 mL in non-treated FW at the same experimental conditions. Therefore, this study signified that hydrothermal pretreatment is an effective and a beneficial technique added to the waste through the generation of biogas energy.
Non-noble metal catalysts for dry reforming of methane: Challenges, opportunities, and future directions
Authors: Alhassan Mansur , Bin Bahari Mahadi , Hamad Khalifa Owgi Abdelrahman , Van Tran Thuan
Published: April 2024

The utilization of non-noble metal catalysts for the dry reforming of methane (DRM) has gained significant attention in recent years due to the increasing demand for clean and sustainable energy sources. DRM involves the conversion of methane (CH4) and carbon (IV) oxide (CO2) into synthesis gas (syngas), a valuable mixture of hydrogen (H2) and carbon monoxide (CO). Commercialization of non-noble metal catalysts for this reaction presents several challenges that must be addressed to achieve practical implementation. This short review discusses the challenges, opportunities, and future directions of non-noble metal catalysts for DRM. First, the limitations associated with the intrinsic activity and stability of non-noble metals, such as nickel, cobalt, and iron, are explored. Enhancing catalyst performance through compositional modifications, the incorporation of promoters and supports, are ways to overcome these challenges. Directions that hold promise for advancing non-noble metal catalysts in DRM, including the advanced exploration of bimetallic catalysts for synergistic effects, and the integration of non-noble metals into novel catalytic systems, were among the future proposals, while non-noble metal catalysts have the potential to revolutionize the production of syngas and contribute significantly to the transition towards sustainable energy solutions.
Development of the TOD.id Mobile App
Authors: Dewanto Hardy , Berawi Mohammed Ali , Saroji Gunawan , Sari Mustika
Published: April 2024

The rise of large cities worldwide has spurred the emergence of Transit Oriented Development (TOD) as an urban planning concept. Indonesia, including Jakarta, has begun implementing TOD strategies. To facilitate TOD in Indonesia, this study proposes a conceptual mobile app, TOD.id, informed by preliminary research. It introduces a novel tax approach, Land Value Capture (LVC) tax, to address funding challenges, which account for up to 53.8% of the problem. However, TOD.id remains in a developmental phase, with all features in the conceptual stage, making it unsuitable for immediate market launch. During this stage, this research aims to enhance the TOD.id mobile app by refining existing features and exploring potential new functionalities, which will be based by literature review and benchmarking against similar existing apps in Indonesia. The study employs a desk study method, a qualitative benchmark study method, and the collection of qualitative data. The outcomes of this research are expected to pave the way for the optimal realization of TOD.id in the Indonesian market, aligning with the projections from previous studies.
Numerical Simulation of the Effect of Particle Size Distribution on Fluidized Bed Gasifier
Authors: Aklis Nur , Wijianto  , Asmindra Nulul
Published: April 2024

The rapid development of technology and industrialization has confronted humanity with two important problems: the depletion of fossil energy resources and environmental damage. This study aims to determine the effect of the particle size distribution of the bed on the composition of the produced syngas which has the potential to replace fossil fuels. The particle bed used is silica sand with 4 variations of particle size distribution with a diameter of 600-1000 µm. The results of this study indicate that the larger the particle size distribution of the bed can reduce the temperature distribution and composition of the syngas produced. The highest temperature distribution was found in the 1st particle size distribution variation of 1060.23 K. The highest syngas composition was found in the 3rd particle size distribution variation of 2.21% CH4, 19.68% CO, 6.21% CO2, and 18.51% H2The highest syngas composition was found in the 3rd particle size distribution variation of 2.21% CH4, 19.68% CO, 6.21% CO2, and 18.51% H2. The lowest temperature distribution was obtained in the 3rd particle size distribution variation of 1057.77 K. The lowest syngas composition was found in the 4th particle size distribution 1.99% CH4, 17.71% CO, 5.63% CO2, and 16.66% H2.
Design of a power factor repair tool for UKM
Authors: Umar  , Khoirudin Ahmad , Tri Marie Beth
Published: April 2024

The home industry has an important role in improving the community's economy. Energy needs also increase, with this the existing load on the home industry becomes more varied, especially inductive loads that cause a decrease in power factor, this needs to be overcome by improving the power factor by adding a compensator to the network. Because production on a home industry scale is not as continuous in large industries, a power factor improvement tool is needed that works automatically. This study aims to design a power factor improvement tool that works automatically to improve the power factor in the home industry, where the tool works according to network requirements. The Arduino micro controller is used as an automatic controller in the design of this power factor improvement tool, with input using a voltage sensor and a current sensor SCT-013, which is then processed by Arduino to get the power factor value and control the relay to adjust the capacitor requirements to compensate for the inductive load on the network. The results of this study are that the power factor in the household industry can be improved to more than 0.9, the power used in the network is more effective and is absorbed by the load more effectively and the reactive power in the network becomes small or even non- existent.
Liability-driven investment for pension funds: stochastic optimization with real assets
Authors: Jang Chul , Clare Andrew , Owadally Iqbal
Published: April 2024

Using a multi-stage stochastic programming method, we suggest an optimal liability-driven investment (LDI) strategy for a closed defined-benefit pension fund including real assets. The objective is to jointly optimize contribution, funding ratio, and buyout cost, subject to a constraint on downside risk in terms of expected shortfall of assets relative to liabilities. Over a 10-year planning horizon, the optimal LDI strategy with a key-rate duration-matching bond portfolio outperforms the corresponding strategy with a duration-convexity matching bond portfolio as well as a strategy with an aggregate bond index-tracking portfolio. When real assets are introduced, the optimal LDI strategy includes significant investment in infrastructure and real estate, illiquidity notwithstanding. Nevertheless, delays in sales of real assets induced by illiquidity can increase downside risk.
In the fourth person singular: pragmatism, anarchism, and the earth
Authors: Savransky Martin
Published: April 2024

Nothing has done more to cement William James’s reputation than his unrepentant individualism. In a present marked by the challenge of imagining modes of transformative action worthy of our planetary travails, James’s individualism appears dated, unworthy of the present. Yet such judgement neglects its pragmatic dimension, as well as its political connections to James’s anarchistic pluralism. Situating anarchism at the centre of James’s vision, this article argues that his defence of individuals constitutes no ontological postulate but forms part of a speculative theory of change. Rather than apologia for individual heroism, James’s individualism is better understood in the impersonal voice of the “fourth person singular:” individual lives matter not as originary sources of heroic action but as zones of divergence through which terrestrial forces of mutation and metamorphosis pass. Revisiting connections between James’s individualism, pragmatism, and anarchism, the article offers a radical reappraisal of James’s thought as a vital method for intensifying unruly forces of transformation on an earth unstable and unsafe.
Nano-kirigami/origami: A traditional artform advances modern electronics
Authors: Shapiro Maura
Published: April 2024

Optical scale structures that transform from two to three dimensions modulate optical properties for next-generation optoelectronic devices.
Two-photon absorption cross sections of pulsed entangled beams
Authors: Schlawin Frank
Published: April 2024

Entangled two-photon absorption (ETPA) could form the basis of nonlinear quantum spectroscopy at very low photon fluxes, since, at sufficiently low photon fluxes, ETPA scales linearly with the photon flux. When different pairs start to overlap temporally, accidental coincidences are thought to give rise to a “classical” quadratic scaling that dominates the signal at large photon fluxes and, thus, recovers a supposedly classical regime, where any quantum advantage is thought to be lost. Here, we scrutinize this assumption and demonstrate that quantum-enhanced absorption cross sections can persist even for very large photon numbers. To this end, we use a minimal model for quantum light, which can interpolate continuously between the entangled pair and a high-photon-flux limit, to analytically derive ETPA cross sections and the intensity crossover regime. We investigate the interplay between spectral and spatial degrees of freedom and how linewidth broadening of the sample impacts the experimentally achievable enhancement.
Magnetic anisotropy driven by ligand in 4d transition-metal oxide SrRuO3
Authors: Wakabayashi Yuki K. , Kobayashi Masaki , Seki Yuichi , Kotani Yoshinori , Ohkochi Takuo , Yamagami Kohei , Kitamura Miho , Taniyasu Yoshitaka , Krockenberger Yoshiharu , Yamamoto Hideki
Published: April 2024

The origin of magnetic anisotropy in magnetic compounds is a longstanding issue in materials science, and nonmagnetic ligand ions are considered to contribute little to magnetic anisotropy. Here, we introduce the concept of ligand-driven magnetic anisotropy in a complex transition-metal oxide. We conducted x-ray magnetic circular dichroism spectroscopies at the Ru and O edges in the 4d ferromagnetic metal SrRuO3. Systematic variation of the sample thickness in the range of ≤10 nm allowed us to control the localization of Ru 4d t2g states, which affects the magnetic coupling between the Ru and O ions. We observe that the orbital magnetic moment of the ligand O 2p orbitals induced through the charge transfer to the Ru 4d t2g states becomes anisotropic first, and the anisotropic magnetic moment of Ru and, therefore, the entire system is induced via magnetic coupling between Ru 4d and O 2p orbitals.
Bacterial vaginosis after menopause: factors associated and women’s experiences: a cross-sectional study of Australian postmenopausal women
Authors: Stewart Linde L. , Vodstrcil Lenka A. , Coombe Jacqueline , Bradshaw Catriona S. , Hocking Jane S.
Published: April 2024

Background Bacterial vaginosis (BV) is the most common cause of vaginal discharge in reproductive age women; however, little is known about it after menopause. We aimed to learn more about BV in Australian postmenopausal women. Methods We conducted an online survey (July–September 2021). Participants were recruited via social media and professional networks and asked about demographic characteristics, sexual history and BV experiences. Outcomes of interest were the proportion who had heard of BV, had BV ever, or had BV after menopause. Factors associated with these outcomes were assessed using logistic regression. Results Of 906 participants, 83% were included in the analysis. Overall, 37.9% had heard of BV, 11.0% reported having a BV diagnosis ever, 6.3% reported having a BV diagnosis after menopause and 4.4% reported having a BV diagnosis only after menopause. Multivariable analysis found that among all women the odds of having a BV diagnosis after menopause were increased for those who had BV before menopause, had douched in the past 12 months, or had a previous STI diagnosis. Among those in a sexual relationship, a BV diagnosis after menopause was associated with a BV diagnosis before menopause, or being in a sexual relationship of 5 years or less in duration. About half who reported BV after menopause described recurrences, distress, and a detrimental effect on sexual relationships. Conclusions BV in postmenopausal women is associated with sexual activity, and impacts negatively on their lives. Research into BV should not be limited to reproductive age women.
An estimate of the marginal annual economic contribution of wild-pig hunting in Texas
Authors: McKee Sophie C. , Carlisle Keith M. , Tomeček John , Shwiff Stephanie A. , Connally Rachael , Frank Maureen , Bodenchuk Mike , Didero Nicole
Published: April 2024

Context Wild-pig hunting is a culturally significant recreational and commercial activity in Texas, but the overall impacts are contested. Except for one 1980s study, there has been no research to formally quantify any economic benefits of wild-pig hunting in Texas, which is an important component for weighing the costs and benefits of wild-pig presence in the state. Aims and methods To fill that research gap, we surveyed a sample of resident and non-resident 2018–2019 hunting-license holders in Texas about various topics related to their wild-pig hunting activities, including expenditures. Key results On the basis of the 37,317 responses received, we estimated that the marginal annual direct economic benefit of wild-pig hunting to the Texas economy ranges between US$68.5 million and US$188.0 million (2022 dollar values). Given that we were not able to distinguish whether purchases were made in or out of state for expenses provided, we believe this range is an upper estimate. Conclusion and implications Although hunting is an important consideration in the discussion of wild-pig management, this estimate is dwarfed by the estimated total damage costs associated with wild pigs in Texas.
Brain-derived neurotrophic factor scales presynaptic calcium transients to modulate excitatory neurotransmission
Authors: Wang Camille S. , McCarthy Clara I. , Guzikowski Natalie J. , Kavalali Ege T. , Monteggia Lisa M.
Published: April 2024

Brain-derived neurotrophic factor (BDNF) plays a critical role in synaptic physiology, as well as mechanisms underlying various neuropsychiatric diseases and their treatment. Despite its clear physiological role and disease relevance, BDNF’s function at the presynaptic terminal, a fundamental unit of neurotransmission, remains poorly understood. In this study, we evaluated single synapse dynamics using optical imaging techniques in hippocampal cell cultures. We find that exogenous BDNF selectively increases evoked excitatory neurotransmission without affecting spontaneous neurotransmission. However, acutely blocking endogenous BDNF has no effect on evoked or spontaneous release, demonstrating that different approaches to studying BDNF may yield different results. When we suppressed BDNF-Tropomyosin receptor kinase B (TrkB) activity chronically over a period of days to weeks using a mouse line enabling conditional knockout of TrkB, we found that evoked glutamate release was significantly decreased while spontaneous release remained unchanged. Moreover, chronic blockade of BDNF-TrkB activity selectively downscales evoked calcium transients without affecting spontaneous calcium events. Via pharmacological blockade by voltage-gated calcium channel (VGCC) selective blockers, we found that the changes in evoked calcium transients are mediated by the P/Q subtype of VGCCs. These results suggest that BDNF-TrkB activity increases presynaptic VGCC activity to selectively increase evoked glutamate release.
Refining greenhouse gas emission factors for Indonesian peatlands and mangroves to meet ambitious climate targets
Authors: Murdiyarso Daniel , Swails Erin , Hergoualc’h Kristell , Bhomia Rupesh , Sasmito Sigit D.
Published: April 2024

For countries’ emission-reduction efforts under the Paris Agreement to be effective, baseline emission/removals levels and reporting must be as transparent and accurate as possible. For Indonesia, which holds among the largest area of tropical peatlands and mangrove forest in the world, it is particularly important for these high-carbon ecosystems to produce high-accuracy greenhouse gas inventory and to improve national forest reference emissions level/forest reference level. Here, we highlight the opportunity for refining greenhouse gas emission factors (EF) of peatlands and mangroves and describe scientific challenges to support climate policy processes in Indonesia, where 55 to 59% of national emission reduction targets by 2030 depend on mitigation in Forestry and Other Land Use. Based on the stock-difference and flux change approaches, we examine higher-tier EF for drained and rewetted peatland, peatland fires, mangrove conversions, and mangrove on peatland to improve future greenhouse gas flux reporting in Indonesia. We suggest that these refinements will be essential to support Indonesia in achieving Forest and Other Land Use net sink by 2030 and net zero emissions targets by 2060 or earlier.
Quantitative study of random walk parameters in node2vec model
Authors: Li Yuanbiao , Yang Bo
Published: April 2024

In this paper, the Monte Carlo simulation method is used to investigate a generalized random walk model based on node2vec which is a popular algorithm in network embedding and has been widely applied in various domains such as link prediction, node classification, recommendation systems, etc. The aim is to quantitatively study the impact of the random walk parameters(including the number of walks per initial node r, the length of each walk l, the return parameter α, the common neighbor parameter β, and the outgoing parameter γ) on the embedding results. Specifically, the cross entropy is utilized as an observation to compare the difference between the frequency of nodes after random walks and the normalized degree sequence of nodes. The results show that the clustering coefficient significantly impacts the cross entropy. For networks with high clustering coefficient, the value of β should closely approximate that of γ, whereas for networks with low clustering coefficient, the value of β should be significantly smaller than that of γ. The value of α should be less than or equal to the minimum values between β and γ. Finally, the embedding effects of different random walk parameters are tested using node classification and link prediction tasks in real-world networks, and the results indicate that cross entropy can provide guidance for obtaining high-quality node embedding.
Influence of cladding tube structure on transmission characteristics of negative curvature terahertz fiber
Authors: Yan Dexian , Yuan Ziwei , Qiu Jianzhong , Li Xiangjun
Published: April 2024

A novel type of polarization negative curvature terahertz fiber has been designed, which has a cladding region composed of two long semi-circular cladding tubes in the horizontal direction and four long semi-elliptical cladding tubes in the oblique direction. The optimal fiber dimensions are determined to investigate the internal relationship between polarization characteristics and fiber cladding structure. The transmission performances of the negative curvature fiber are investigated by varying the thickness of fiber cladding tubes and adjusting the structural characteristics of cladding tubes in different directions. Relatively good transmission performances can be obtained with a cladding tube thickness of 80 μm. The birefringence can be stably maintained at the order of 10−4, and the confinement loss of the x-polarized mode at 2.55 THz is 0.036 dB cm−1. Moreover, the dispersion coefficient of the two polarized modes is stable between ±0.6 ps (THz·cm)−1 in the 2.3–2.6 THz band. The bent performance of the designed fiber at 2.52 THz is also discussed. The results show that the fiber has low bending sensitivity, and can still maintain excellent birefringence and low confinement loss in the bending state. For the y polarization, the birefringence can be basically stabilized at the order of 10−4 within a bending radius of 10–60 cm.
New quantum LDPC codes based on Euclidean Geometry
Authors: Feng Ya’nan , Tang Chuchen , Bai Chenming
Published: April 2024

With the advancements in quantum error correction technique, quantum low density parity check (QLDPC) codes have emerged as a promising area in the field of quantum error correction. This paper focuses on the requirement of QLDPC codes based on points excluding the origin, and lines that do not pass through the origin of Euclidean Geometry. It also explores QLDPC codes based on all the points and lines. Finally, a series of simulation analyses are presented.
What is the Role of Gravity, Turbulence and Magnetic Fields in High-mass Star Formation Clouds?
Authors: Luo An-Xu , Liu Hong-Li , Li Guang-Xing , Pan Sirong , Yang Dong-Ting
Published: April 2024

To explore the potential role of gravity, turbulence and magnetic fields in high-mass star formation in molecular clouds, this study revisits the velocity dispersion–size (σ–L) and density–size (ρ–L) scalings and the associated turbulent energy spectrum using an extensive data sample. The sample includes various hierarchical density structures in high-mass star formation clouds, across scales of 0.01–100 pc. We observe σ ∝ L
0.26 and ρ ∝ L
−1.54 scalings, converging toward a virial equilibrium state. A nearly flat virial parameter–mass (α
vir−M) distribution is seen across all density scales, with α
vir values centered around unity, suggesting a global equilibrium maintained by the interplay between gravity and turbulence across multiple scales. Our turbulent energy spectrum (E(k)) analysis, based on the σ–L and ρ–L scalings, yields a characteristic E(k) ∝ k
−1.52. These findings indicate the potential significance of gravity, turbulence, and possibly magnetic fields in regulating dynamics of molecular clouds and high-mass star formation therein.
Multi-scale modelling of the epileptic brain: advantages of computational therapy exploration
Authors: Hong Rongqi , Zheng Tingting , Marra Vincenzo , Yang Dongping , Liu Jian K
Published: April 2024

Objective: Epilepsy is a complex disease spanning across multiple scales, from ion channels in neurons to neuronal circuits across the entire brain. Over the past decades, computational models have been used to describe the pathophysiological activity of the epileptic brain from different aspects. Traditionally, each computational model can aid in optimizing therapeutic interventions, therefore, providing a particular view to design strategies for treating epilepsy. As a result, most studies are concerned with generating specific models of the epileptic brain that can help us understand the certain machinery of the pathological state. Those specific models vary in complexity and biological accuracy, with system-level models often lacking biological details. Approach: Here, we review various types of computational model of epilepsy and discuss their potential for different therapeutic approaches and scenarios, including drug discovery, surgical strategies, brain stimulation, and seizure prediction. We propose that we need to consider an integrated approach with a unified modelling framework across multiple scales to understand the epileptic brain. Our proposal is based on the recent increase in computational power, which has opened up the possibility of unifying those specific epileptic models into simulations with an unprecedented level of detail. Main results: A multi-scale epilepsy model can bridge the gap between biologically detailed models, used to address molecular and cellular questions, and brain-wide models based on abstract models which can account for complex neurological and behavioural observations. Significance: With these efforts, we move toward the next generation of epileptic brain models capable of connecting cellular features, such as ion channel properties, with standard clinical measures such as seizure severity.
A dynamic brain network decomposition method discovers effective brain hemodynamic sub-networks for Parkinson’s disease
Authors: Lu Jiewei , Zhang Xinyuan , Shu Zhilin , Han Jianda , Yu Ningbo
Published: April 2024

Objective. Dopaminergic treatment is effective for Parkinson’s disease (PD). Nevertheless, the conventional treatment assessment mainly focuses on human-administered behavior examination while the underlying functional improvements have not been well explored. This paper aims to investigate brain functional variations of PD patients after dopaminergic therapy. Approach. This paper proposed a dynamic brain network decomposition method and discovered brain hemodynamic sub-networks that well characterized the efficacy of dopaminergic treatment in PD. Firstly, a clinical walking procedure with functional near-infrared spectroscopy was developed, and brain activations during the procedure from fifty PD patients under the OFF and ON states (without and with dopaminergic medication) were captured. Then, dynamic brain networks were constructed with sliding-window analysis of phase lag index and integrated time-varying functional networks across all patients. Afterwards, an aggregated network decomposition algorithm was formulated based on aggregated effectiveness optimization of functional networks in spanning network topology and cross-validation network variations, and utilized to unveil effective brain hemodynamic sub-networks for PD patients. Further, dynamic sub-network features were constructed to characterize the brain flexibility and dynamics according to the temporal switching and activation variations of discovered sub-networks, and their correlations with differential treatment-induced gait alterations were analyzed. Results. The results demonstrated that PD patients exhibited significantly enhanced flexibility after dopaminergic therapy within a sub-network related to the improvement of motor functions. Other sub-networks were significantly correlated with trunk-related axial symptoms and exhibited no significant treatment-induced dynamic interactions. Significance. The proposed method promises a quantified and objective approach for dopaminergic treatment evaluation. Moreover, the findings suggest that the gait of PD patients comprises distinct motor domains, and the corresponding neural controls are selectively responsive to dopaminergic treatment.
A fast and plug-and-play mechanical connector for microfluidic chips
Authors: Shi Zhenxing , Wang Huiquan , Zhang Yongxing
Published: April 2024

This article introduces a fast and plug-and-play mechanical connector for microfluidic chips. With this connection device, fast and pluggable connection between microfluidic chips and liquid storage tanks can be achieved, allowing microfluidic flow between the storage tank and the chip and between chips while ensuring airtightness and avoiding liquid leakage. The reason for liquid leakage and the maximum sealing pressure are theoretically analyzed from the perspective of surface tension. The relationship between different liquids (surface tension coefficient), air gap distance, and leakage pressure is explored. Furthermore, the effect of fast connection method and capillary connection method on liquid flow inside the chip is compared. The experiment shows that the flow rate using the fast connection method can reach at least 70% of that using the capillary connection method, and can gradually increase to 96% with increasing pressure and flow rate.
Full-scale linear sensing of mode-localized sensors enabled by optimized readout circuit
Authors: Guo Xin , Li Ang , Hu Weiming
Published: April 2024

This paper proposes a novel single-port readout circuit to realize the full-scale linear sensing of mode-localized sensors. In our proposal, in addition to the conventional frequency closed-loop control, the amplitude closed-loop based on automatic gain control (AGC) is adopted to stabilize the amplitude product of resonant units at a normalized value so that the difference of squared amplitudes can be regarded as the sensor readout to characterize the variations of external input signals. A micro-electro-mechanical system (MEMS) mode-localized accelerometer prototype is tested based on our proposed readout circuit. The experiment results demonstrate that the tested accelerometer prototype realizes the linear sensing in the full measurement range and shows a mechanical sensitivity of 0.1182 /g with a maximum non-linearity of -6.54 %, which are basically consistent with the output metric based on the subtraction of reciprocal amplitude ratios (SRAR).
Hybrid electrospinning of blend nanofibrous drug-releasing membrane for wound dressing
Authors: Li Wenwang , Pan Zhentao , Wang Xiang , Li Shufan , Zhang Runyang , Zheng Gaofeng , Jiang Jiaxin
Published: April 2024

The controllable drug-releasing is the key to the application of wound dressing and other bioremediation membrane. In this paper, a hybrid electrospinning method was utilized to fabricate the PVP/PVAc blend nanofibrous membrane. The effects of processing parameters were investigated on the morphology, diameter and dispersion of nanofibers. Drug release test was carried out for PVP/PVAc nanofiber membranes with different mass ratio, showing excellent drug-releasing performance for the blend nanofiber membranes.
Skeleton-reinforced electrospun nanofiber membrane with enhanced mechanical strength
Authors: Wang Xiang , Chen Shaojian , Lin Jinghua , Jiang Jiaxin , Li Shufan , Zhang Runyang , Zheng Gaofeng , Li Wenwang
Published: April 2024

Electrospun membranes are made of thousands of nanofibers and are widely used in many fields. However, their poor mechanical properties seriously restrict their industrialization. In this paper, a simple post fabrication strategy is proposed to enhance the strength of electrospun nanofiber membranes. The polymer skeleton was melted electrohydrodynamic direct-writing into the electrospun nanofiber membrane and penetrated the nanofiber membrane to enhance its mechanical properties. As a verification, composite membrane with polyimide nanofiber and polylactide skeleton was generated, and tensile strength increased from 14.9 MPa to 34.2 MPa without significant loss of fiber morphology. In addition, finite element analysis was conducted. Our method makes it possible to predict the mechanical properties of nanofiber membranes in advance.
Development of a low-power SAR ADC for analog front-end readout circuit of hydrophones
Authors: Liu K. , Fang S. , Wang Y. , Huang Z.
Published: April 2024

A low-power 16 bit 250KSa/s successive approximation analog-to-digital converter (SAR ADC) is designed. The capacitor array consists of a 2-segment sub-capacitor array and high sampling makes the coupling capacitance a unit capacitance, solving the problem of fractional capacitance mismatch. The power consumption is reduced by introducing a common-mode voltage during the switching process of the capacitor array. The circuit uses a 4-stage pre-amplifier and adds a dynamically latched comparator using output misalignment calibration to ensure high accuracy resolution. Simulated in DB Hitek 0.18 μm process, the Fast Fourier Transform(FFT) simulation results for 4096 points show that the signal-to-noise distortion ratio (SNDR) of the ADC can reach 90.2 dB and the effective number of bits (ENOB) can reach 14.69 bit. The average power consumption is 2.507mW at a supply voltage of 5 V, and this holds significant significance for the long-term deep-sea detection capabilities of sonar systems.
Silicon-based waveguide technology for millimeter-wave antennas
Authors: Yan Cao , Hongze Zhang , Guixiong Shi
Published: April 2024

This paper describes a method for the preparation of complex structured waveguides that can be used for millimeter-wave antennas based on a bulk silicon MEMS process. In this paper, a millimeter-wave band array of ridge waveguide slit antennas with multilayer step-matched feeds is realized by this method. A bulk silicon MEMS process is used to realize the complex structure and the high precision and flatness requirements on the millimeter scale, which cannot be achieved by machining. And the step height difference of more than 100um is realized by combining multiple lithography and silicon oxide mask. The step difference is larger than that achievable by dry etching using the etching selection ratio of silicon oxide and silicon. The waveguide fabricated by this method can work well in the millimeter wave band and is used for antenna feeding, power distribution, etc. It is characterized by compact structure, high precision, and high performance.
Machine learning for predicting laser ablation groove characteristics in polycrystalline diamond
Authors: Tan Ruiwang , Yu Zhanjiang , Li Yiquan , Xu Jinkai
Published: April 2024

This paper explores machine learning’s role in predicting laser-machined micro-groove texture on Polycrystalline Diamond (PCD) surfaces. PCD has been used for manufacturing ideal cutting insert due to its exceptional attributes, including hardness and thermal conductivity. Surface micro-texturing enhances accuracy and tool lifespan through micro-textures on tool surfaces. Laser micromachining, especially for its precision and efficiency, stands out among methods. Six regression models—Elastic Net, Random Forest, Gradient Boosting Regression, XGBoost Regression, Bayesian Regression, and Gaussian Process Regression—are used to predict groove depth and width based on laser parameters like energy, defocus, and speed. Experiments involve a nanosecond laser system and a commercial PCD tool. Results indicate both Gradient Boosting and XGBoost excel in predicting micro-groove texture. XGBoost slightly outperforms, credited to its enhancements over Gradient Boosting. This paper concludes that machine learning models, especially XGBoost and Gradient Boosting, effectively forecast micro-groove features on laser-machined PCD surfaces, offering insights for further research and practical applications in this domain.
Study on TSV insulating medium based on SACVD process
Authors: Shen Yanfei , Wang Lei , Xu Qiankun , Zhou Feng , Bai Yang , Jiang Lili , Yu Yuanwei , Huang Min
Published: April 2024

TSV silicon switching board technology has the advantages of short global interconnection, small delay, low power consumption and high integration. The dielectric insulation performance in the TSV hole will directly affect the signal integrity and power integrity of the TSV silicon switching board. The insulating dielectric layer of TSV requires good forming ability and step covering, and lower leakage current and good heat resistance reliability. In this paper, the filling capacity of SACVD process is analyzed, the coverage rate of SACVD process is studied under different process parameters, and the leakage current of silicon dioxide film is measured by planar capacitance structure. Finally, the leakage current test of the TSV pairs is carried out online. Before the substrate thinning, the leakage current of the two blind hole TSV pairs is measured by the probe station. The voltage ranges form 0 to 50V, and the leakage current ranges from a few pA to a few hundred pA.
Thermal-Mechanical Property of High Aspect Ratio TSV in Advanced IC integration and Packaging
Authors: Bai Yu , Zhang Hongze , Huang Min
Published: April 2024

Advanced packaging of integrated circuits (IC) plays a critical role on the way towards high performance, high density, low power consumption and light weight of electronics. Through-silicon vias (TSV) is the heart of 3D IC integration and packaging. However, copper protrusion due to mismatch of coefficients of thermal expansion (CTE) between copper and silicon, which may result in the dielectric material breakdown, becomes the bottleneck of TSV in high-temperature application. In this paper, thermal-mechanical property of high aspect ratio TSV is investigated through experiments under different annealing process, which will help to accelerate the widely application of TSV in advanced packaging of electronics in the future.
Detection of sodium and potassium ions in human sweat using electrochemical system
Authors: Liu Runye , Zheng Feifan , Zhang Penghui , Fu Yongdong , Qiu Xianbo , Yu Duli , Zhang Lulu
Published: April 2024

Sweat contains a large number of biomarkers which can be used to indicate the healthy state of the body. Real-time detection of ion contents in sweat at trace levels has significant implications for health monitoring and medical diagnosis. In this work, an electrochemical detection system combining an electrochemical detection circuit and an electrochemical sensor with ion selectivity was developed. Based on the system sodium and potassium ions were detected at room temperature using the open circuit voltage-time (OCPT) method. The ion-selective sensors have high sensitivity (98.3 mV/decade for sodium ion detection and 99 mV/decade for potassium ion detection), and good stability. Miniaturized detection system makes it possible to detect sweat on wearable devices and holds great promise in the wearable field.
Influence of surface roughness on the fluid flow in microchannel
Authors: Li Yong , Zhang Ziqun , Ji Yutong , Wang Lixin , Li Dayong
Published: April 2024

Surface roughness is a crucial factor of fluid flow in microfluidic channels. Most of the existing studies focus on the effect of regular microstructured surfaces on fluid flow, while researchs about the impact of random rough surfaces on fluid flow remains limited. Therefore, in this study, a random rough surface model and two microstructured surface models were established, and the effects surface roughness on the fluid flow at Wenzel state and Cassie-Baxter state were studied using COMSOL multi-physics simulation software. Our findings reveal that both the flow velocity and the fluid flow rate at the microchannel outlet decreases with the surface roughness increases. Notably, the flow rate and velocity of the fluid flow at Cassie-Baxter state is higher than that of fluid flow at Wenzel state.
Improving soft X-ray imaging contrast uniformity of 50nm Au zone plate by optimizing pulse plating
Authors: Zhang Kuanqiang , Chen Lijuan , Guo Chenfei , Ding Xu , Xiong Ying , Guan Yong , wu Zhao , Tian Yangchao , Liu Gang
Published: April 2024

The Fresnel zone plate plays a pivotal role in X-ray imaging systems, directly influencing the uniformity of imaging contrast. Achieving uniform imaging contrast imposes stringent requirements on the linewidth and height uniformity of the zone plate. The current mainstream method for zone plate fabrication involves utilizing electron beam lithography in conjunction with electroplating. However, in structures with large aspect ratios, precise deposition of gold to the bottom of the trench through electroplating becomes increasingly challenging to control. In this study, we employed a pulse plating process to enhance the uniformity of the plating height. Detailed investigations were conducted to analyze the effects of pulse current density, pulse duty cycle, and pulse frequency on plating height. Utilizing pulse plating, we successfully fabricated a zone plate with an outermost width of 50 nm and a thickness of approximately 245 nm. Structural analysis showed that the plating height uniformity is improved to better than 5%. The high uniformity imaging pattern was obtained by using the Siemens star test pattern at the soft x-ray imaging station at NSRL. The spatial resolution was down to 50 nm.
A MEMS Disk Gyroscope with High Fabrication Precision, High Quality Factor (>810k) and High Overload Characteristic (>15000g)
Authors: Wang Chengxiang , Wu Kai , Wang Xinyu , Li Qingsong , Zhang Yongmeng , Wu Yulie , Wu Xuezhong , Xiao Dingbang
Published: April 2024

This paper presents an electromagnetic MEMS disk gyroscope based on fused silica to enhance the accuracy of MEMS gyros under high overload conditions. A laser-induced modified wet etching (LIE) technology was utilized for gyro fabrication and a detailed analysis was conducted on the factors affecting quality factor (Q-value) of the gyro. The LIE process parameters were optimized using a four-factor and three-level orthogonal experiment, and structure compensation were implemented to address machining errors. Impact capability of the resonator and mode characterization as well as Q-value of the gyro revealing that the resonator can withstand high overload up to 15000g, frequency of working mode is 15382.2Hz and 15379.8Hz, respectively, which close to simulated result of 15443Hz exhibited high process precision. The corresponding Q-values of the driving mode and sensing mode are 817k and 819k, respectively, indicating high-performance potential.
Mapping the exposure of tourism to weather extremes: the need for a spatially-explicit gridded dataset for disaster risk reduction
Authors: Camatti Nicola , Hrast Essenfelder Arthur , Giove Silvio
Published: April 2024

Tourism is a highly important economic sector worldwide, yet it is often less than optimally represented in terms of detailed spatial information. An accurate spatial representation of tourism can provide valuable insights into the spatial distribution of tourism vulnerabilities and exposure, allowing policymakers to make informed decisions and develop effective strategies for disaster risk reduction and climate change adaptation policies. Here, we stress the need for and propose a first prototype of an open-access spatially-explicit gridded database based on social media data for over 150 different tourism-related classes that depicts tourism density (supply and demand) and perceived satisfaction in Europe. We showcase the potential benefits of such database by mapping the exposure of specific tourism sectors to a range of weather extremes, including floods, windstorms, and heat stress. Based on these results, we argue that a homogeneous spatially-explicit database of tourism is essential to support efficient investments in preparedness and disaster resilience.
Decision support system for determining the location of rubber weir construction as an effort to meet raw water needs in Rembang, Indonesia
Authors: Adi H.P. , Wahyudi S.I. , Mariolo M.A. , Sophyanto A.P , Wahyudi R.S.
Published: April 2024

Rembang is one of the regency that was significantly affected by the drought since 2019. The areas affected by drought have gradually expanded so that the demand for raw water in Rembang is increasing. The flow of the Karanggeneng River which empties to the north of Rembang can be used to make rubber dams as a solution to overcome the shortage of raw water availability. The aim of this study is to determine alternative locations for rubber weirs to be built on the Karanggeneng River. The standards or criterias by which the place was chosen of the rubber weir, namely distance from the estuary, topographical considerations, distance from the Water Treatment Plant (WTP), operational ease of access and the interests of fishing boats. There are 3 alternative locations, namely Karang Village, Waru Tengah Village and Waru Kawisto Village. Data were obtained by conducting interviews with respondents consisting of experts and local residents. After that, the Analytical Hierarchy Process (AHP) is used to process the data. The research results show that the order of priority criteria for planning rubber weirs is the importance of fishing boats and Waru Tengah Village is the most prioritized location of a rubber weir’s construction.