bluuebunny/crossref_metadata_2025 huggingface dataset:
Pressure-induced photocurrent enhancement and metallization in van der Waals compound SiTe2
Authors: Li Zhongyang , Zeng Xiaohui , Bu Kejun , Zhu Zhikai , Wang Yiming , Yuan Jian , Hou Xiaofei , Shu Haiyun , Yan Shuai , Yang Wenge , Kong Lingping , Liu Gang , Guo Yanfeng
Published: August 2024

Layered van der Waals (vdW) dichalcogenides are distinguished by their unique crystal structures and high structural tunability, rendering them suitable for applications in optics and optoelectronics. Despite significant processes, some fundamental questions remain in two-dimensional (2D) vdW dichalcogenides, such as clarifying detailed structure–property relationship and further improving the optoelectronic performance. Herein, by applying pressure to tune the crystal structure in 2D vdW dichalcogenide SiTe2, we realized a five orders of magnitude boost in photocurrent at 8 GPa. Such an enhancement is attributed to bandgap narrowing and an increased carrier concentration. Furthermore, bandgap closing and metallization were observed at 15.4 GPa, further suggesting the significant change of electronic structure upon compression. This study not only elucidates the intriguing pressure-induced behavior of SiTe2 but also paves the way for harnessing the unique pressure-responsive properties of 2D vdW dichalcogenides in advanced optoelectronic systems.
Effects of shear and bending strains on domain structures in freestanding ferroelectric thin films from phase-field simulations
Authors: Guo Changqing , Wang Jing , Huang Houbing
Published: August 2024

Freestanding ferroelectric thin films, free from substrate constraints, present a platform for advanced strain engineering owing to their exceptional mechanical flexibility. The strain state in freestanding ferroelectric thin films can be modulated through various mechanical deformations, enabling precise control over the physical properties and performance of the ferroelectric films. Here, we utilized phase-field simulations to explore the polarization evolution and switching behavior of freestanding BaTiO3 ferroelectric thin films under bending and shear strains. Our findings reveal that shear strain transforms flux-closure domains into a monoclinic phase, increasing the coercive field, maximum polarization, and remanent polarization, thereby broadening the ferroelectric polarization–electric field hysteresis loop. The underlying mechanism involves the competition between elastic and electrostatic energies, which becomes more pronounced with increasing shear strain. Additionally, this contrasts with the modulation of domain structures by bending strain, which causes a rightward shift in the ferroelectric polarization–electric field hysteresis loop due to the flexoelectric fields generated by bending deformation. These findings provide profound insights into the strain effects in ferroelectrics, highlighting the complex interplay between mechanical deformation and electrical response. The ability to manipulate domain structures and polarization behaviors through controlled mechanical strains paves the way for designing high-performance, flexible ferroelectric devices.
Length control emerges from cytoskeletal network geometry
Authors: McInally Shane G. , Reading Alexander J. B. , Rosario Aldric , Jelenkovic Predrag R. , Goode Bruce L. , Kondev Jane
Published: August 2024

Many cytoskeletal networks consist of individual filaments that are organized into elaborate higher-order structures. While it is appreciated that the size and architecture of these networks are critical for their biological functions, much of the work investigating control over their assembly has focused on mechanisms that regulate the turnover of individual filaments through size-dependent feedback. Here, we propose a very different, feedback-independent mechanism to explain how yeast cells control the length of their actin cables. Our findings, supported by quantitative cell imaging and mathematical modeling, indicate that actin cable length control is an emergent property that arises from the cross-linked and bundled organization of the filaments within the cable. Using this model, we further dissect the mechanisms that allow cables to grow longer in larger cells and propose that cell length–dependent tuning of formin activity allows cells to scale cable length with cell length. This mechanism is a significant departure from prior models of cytoskeletal filament length control and presents a different paradigm to consider how cells control the size, shape, and dynamics of higher-order cytoskeletal structures.
UPF1 deficiency enhances mitochondrial ROS which promotes an immunosuppressive microenvironment in pancreatic ductal adenocarcinoma
Authors: Su Wenjuan , Kochen Rossi Juan , Nuevo-Tapioles Cristina , Chen Ting , Kawaler Emily , Branco Cristina , Wong Kwok-kin , Simeone Diane M. , Gardner Lawrence B. , Philips Mark R.
Published: August 2024

Upstream frameshift 1 (UPF1) is an RNA helicase involved in a number of mRNA regulatory processes including nonsense-mediated decay. Mutations in the
UPF1
locus that reduce its expression have been associated with adenosquamous carcinoma of the pancreas, a particularly aggressive form of the disease. To determine the effect of
Upf1
suppression in a murine model of pancreatic adenocarcinoma, we silenced with shRNA
Upf1
in cells derived from an autochthonous tumor in an LSL-Kras
G12D/+
; Trp53
R172H/+
; Pdx-1
Cre/+
mouse (KPC) and orthotopically implanted these cells in the pancreas of C57BL/6 mice. Tumors derived from Upf1-deficient cells were markedly larger than those derived from control cells, a difference observed only in immunocompetent mice. The immune infiltrate of Upf1-deficient tumors was enriched in myeloid-derived suppressor cells (MDSCs) and depleted of CD8
+
cells compared to control KPC tumors. Upf1-deficient KPC cells secreted inflammatory cytokines including G-CSF and CXCL2, known to recruit MDSCs. Cytokine secretion from Upf1-deficient KPC cells was induced by increased levels of mitochondrial reactive oxygen species (ROS), which in turn were due to an increase in complex I activity in the electron transport chain. Thus, Upf1 helicase deficiency leads to increased mitochondrial complex I activity which produces ROS that signals for cytokine release that drives immune suppression and enhanced tumor growth.
Real-space visualization of a defect-mediated charge density wave transition
Authors: Hart James L. , Pan Haining , Siddique Saif , Schnitzer Noah , Mallayya Krishnanand , Xu Shiyu , Kourkoutis Lena F. , Kim Eun-ah , Cha Judy J.
Published: August 2024

We study the coupled charge density wave (CDW) and insulator-to-metal transitions in the 2D quantum material 1T-TaS
2
. By applying in situ cryogenic 4D scanning transmission electron microscopy with in situ electrical resistance measurements, we directly visualize the CDW transition and establish that the transition is mediated by basal dislocations (stacking solitons). We find that dislocations can both nucleate and pin the transition and locally alter the transition temperature
T
c
by nearly ~75 K. This finding was enabled by the application of unsupervised machine learning to cluster five-dimensional, terabyte scale datasets, which demonstrate a one-to-one correlation between resistance—a global property—and local CDW domain-dislocation dynamics, thereby linking the material microstructure to device properties. This work represents a major step toward defect-engineering of quantum materials, which will become increasingly important as we aim to utilize such materials in real devices.
Dual role of neuroplastin in pancreatic β cells: Regulating insulin secretion and promoting islet inflammation
Authors: Kitamura Rie Asada , Hummel Devynn , Ustione Alessandro , Piston David W. , Urano Fumihiko
Published: August 2024

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an endoplasmic reticulum (ER)-resident secretory protein that reduces inflammation and promotes proliferation in pancreatic β cells. Numerous studies have highlighted the potential of MANF as a therapeutic agent for diabetes mellitus (DM), making it essential to understand the mechanisms underlying MANF’s functions. In our previous search for a molecule that mediates MANF signaling, we identified Neuroplastin (NPTN) as a binding partner of MANF that localizes on the cell surface. However, the roles of NPTN in pancreatic β cells remain unclear. In this study, we generated β cell–specific
Nptn
knockout (KO) mice and conducted metabolic characterization. NPTN deficiency improved glucose tolerance by increasing insulin secretion and β cell mass in the pancreas. Moreover, proliferation and mitochondrial numbers in β cells increased in
Nptn
KO islets. These phenotypes resulted from elevated cytosolic Ca
2+
levels and subsequent activation of downstream molecules. Simultaneously, we demonstrated that NPTN induces the expression of proinflammatory cytokines via the TRAF6–NF-κB axis in β cells. Additionally, NPTN deficiency conferred resistance to streptozotocin-induced diabetic phenotypes. Finally, exogenous MANF treatment in islets or β cells led to similar phenotypes as those observed in NPTN-deficient models. These results indicate that NPTN plays important roles in the regulation of insulin secretion, proliferation, and mitochondrial quantity, as well as proinflammatory responses, which are antagonized by MANF treatment. Thus, targeting the MANF–NPTN interaction may lead to a novel treatment for improving β cell functions in DM.
Unbiased MD simulations identify lipid binding sites in lipid transfer proteins
Authors: Srinivasan Sriraksha , Álvarez Daniel , John Peter Arun T. , Vanni Stefano
Published: August 2024

The characterization of lipid binding to lipid transfer proteins (LTPs) is fundamental to understand their molecular mechanism. However, several structures of LTPs, and notably those proposed to act as bridges between membranes, do not provide the precise location of their endogenous lipid ligands. To address this limitation, computational approaches are a powerful alternative methodology, but they are often limited by the high flexibility of lipid substrates. Here, we develop a protocol based on unbiased coarse-grain molecular dynamics simulations in which lipids placed away from the protein can spontaneously bind to LTPs. This approach accurately determines binding pockets in LTPs and provides a working hypothesis for the lipid entry pathway. We apply this approach to characterize lipid binding to bridge LTPs of the Vps13-Atg2 family, for which the lipid localization inside the protein is currently unknown. Overall, our work paves the way to determine binding pockets and entry pathways for several LTPs in an inexpensive, fast, and accurate manner.
Discovery of novel materials through machine learning
Authors: Akinpelu Akinwumi , Bhullar Mangladeep , Yao Yansun
Published: August 2024

Experimental exploration of new materials relies heavily on a laborious trial-and-error approach. In addition to substantial time and resource requirements, traditional experiments and computational modelling are typically limited in finding target materials within the enormous chemical space. Therefore, creating innovative techniques to expedite material discovery becomes essential. Recently, machine learning (ML) has emerged as a valuable tool for material discovery, garnering significant attention due to its remarkable advancements in prediction accuracy and time efficiency. This rapidly developing computational technique accelerates the search and optimization process and enables the prediction of material properties at a minimal computational cost, thereby facilitating the discovery of novel materials. We provide a comprehensive overview of recent studies on discovering new materials by predicting materials and their properties using ML techniques. Beginning with an introduction of the fundamental principles of ML methods, we subsequently examine the current research landscape on the applications of ML in predicting material properties that lead to the discovery of novel materials. Finally, we discuss challenges in employing ML within materials science, propose potential solutions, and outline future research directions.
Single‐atom catalysts for electrocatalytic nitrate reduction into ammonia
Authors: Chao Guojie , Wang Jian , Zong Wei , Fan Wei , Xue Tiantian , Zhang Longsheng , Liu Tianxi
Published: August 2024

Ammonia (NH3) is a versatile and important compound with a wide range of uses, which is currently produced through the demanding Haber-Bosch process. Electrocatalytic nitrate reduction into ammonia (NRA) has recently emerged as a sustainable approach for NH3 synthesis under ambient conditions. However, the NRA catalysis is a complex multistep electrochemical process with competitive hydrogen evolution reaction that usually results in poor selectivity and low yield rate for NH3 synthesis. With maximum atom utilization and well-defined catalytic sites, single atom catalysts (SACs) display high activity, selectivity and stability toward various catalytic reactions. Very recently, a number of SACs have been developed as promising NRA electrocatalysts, but systematical discussion about the key factors that affect their NRA performance is not yet to be summarized to date. This review focuses on the latest breakthroughs of SACs toward NRA catalysis, including catalyst preparation, catalyst characterization and theoretical insights. Moreover, the challenges and opportunities for improving the NRA performance of SACs are discussed, with an aim to achieve further advancement in developing high-performance SACs for efficient NH3 synthesis.
Simulation-based research on enhancing lubricity: investigating wettability and textured surfaces in alkane lubricants under boundary lubrication conditions
Authors: Yi Changli , Hu Chengzhi , Shi Lin , Bai Minli , Li Yubai , Tang Dawei
Published: August 2024

Changing the wettability and surface texturing have a significant impact on lubrication. In this study, the researchers used the molecular dynamics method to investigate how adjusting the interaction between alkanes and the wall affects oil film morphology and frictional properties under boundary lubrication. The findings revealed that the bearing capacity was influenced by both the morphology of the oil film and the strength of solid–liquid adsorption. In cases where the walls had weak wettability, the alkanes formed clusters to effectively separate the walls, while in cases where the walls had strong wettability, the oil film spread and formed a strong adsorption film. The super oleophilic textured surface could enhance the oil film adsorption capacity and replenish the oil film to the friction area in time, and the super oleophobic smooth surface could further reduce the friction coefficient. Therefore, a composite surface consisting of a super oleophilic textured surface and a super oleophobic smooth surface can be designed to enhance the bearing capacity of the oil film and reduce friction.
Understanding the physiological transmission mechanisms of photoplethysmography signals: a comprehensive review
Authors: Li Kai , Sun Jiuai
Published: August 2024

Objective. The widespread adoption of Photoplethysmography (PPG) as a non-invasive method for detecting blood volume variations and deriving vital physiological parameters reflecting health status has surged, primarily due to its accessibility, cost-effectiveness, and non-intrusive nature. This has led to extensive research around this technique in both daily life and clinical applications. Interestingly, despite the existence of contradictory explanations of the underlying mechanism of PPG signals across various applications, a systematic investigation into this crucial matter has not been conducted thus far. This gap in understanding hinders the full exploitation of PPG technology and undermines its accuracy and reliability in numerous applications. Approach. Building upon a comprehensive review of the fundamental principles and technological advancements in PPG, this paper initially attributes the origin of PPG signals to a combination of physical and physiological transmission processes. Furthermore, three distinct models outlining the concerned physiological transmission processes are synthesized, with each model undergoing critical examination based on theoretical underpinnings, empirical evidence, and constraints. Significance. The ultimate objective is to form a fundamental framework for a better understanding of physiological transmission processes in PPG signal generation and to facilitate the development of more reliable technologies for detecting physiological signals.
Correlated qubit coherences stimulated by thermal energy
Authors: Etehadi Abari N , Rakhubovsky A A , Filip R
Published: August 2024

Quantum coherence, the ability of a system to be in a quantum superposition of pure states, is a distinct feature of quantum mechanics that has no direct analog in classical mechanics. Quantum states that possess coherence efficiently outperform their classical counterparts in fundamental science and practical applications, including quantum metrology, computation, and simulation. Generation of coherence without the need to employ strong classical drives remains a challenging and not yet experimentally explored task. Beyond individual thermally-induced coherences already proposed for different experiments, correlated quantum coherences of multiple qubits represent a new target. We prove that correlated qubit coherence emerges thermally stimulated from incoherent states in hybrid superconducting and solid-state systems comprising non-interacting qubits coupled only via Dicke-type interaction to a shared thermal mechanical oscillator, exhibits coherences beyond the Tavis–Cummings coupling and, moreover, can be advantageous in quantum sensing.
Improved preparation of AgNW film and its application in flexible counter electrodes of dye-sensitized and perovskite solar cells
Authors: Yu Long , Wang Zi , Gao Shufang , Cheng Shubo , Deng Fei , Shi Dean , Xiong Yan
Published: August 2024

Silver nanowire (AgNW) has been wildly used to prepare flexible conducting substrate of electronic and optoelectronic devices. By coating a layer of carbon onto a polymer/AgNW substrate, a counter electrode (CE) was obtained and it offers the advantages of high flexibility, light weight, low cost, simple fabrication, and operating efficiently in dye-sensitized solar cells (DSSCs) and perovskite solar cells (PSCs). By modifying the traditional unidirectional roll-coating process of AgNW to cross-directional coating, the morphology and distribution of the AgNW network was improved, which led to increased transmittance and electroconductivity, and subsequently improved cell efficiency of DSSCs and PSCs. The performance of the CEs and solar cells was further promoted by optimized fabrication process of the carbon layer. The as-prepared flexible CEs achieved great enhancement of cell efficiencies, and maximum power conversion efficiencies of 5.17% and 14.32% were obtained by DSSCs and PSCs, respectively.
Coupled topological edge and corner states in two-dimensional phononic heterostructures with nonsymmorphic symmetries
Authors: Huang Hongbo , Chen Jiujiu , Mao Liang
Published: August 2024

The exciting discovery of topological phononic states has aroused great interest in the field of acoustic wave control. However, conventional topological edge states and corner states localized at the interface and corner of the two-phase domain wall structures are limited by single channel transmission characteristics, which decreases the flexibility of designing multi-channel acoustic wave devices. Here, we propose a two-dimensional (2D) topological phononic heterostructure with nonsymmorphic symmetries to realize the multiple interface topological multimode interference effect based on the coupling of topological edge and corner states. Topological phase transitions are achieved by altering the rotation angle of the split-ring scatterers in a square lattice. The coupled edge states are generated by the coupling between the edge states of ordinary-topological-ordinary (OTO) interfaces. Moreover, the higher-order topology of the square phononic crystals (PCs) is characterized by nontrivial bulk polarization, the topological and coupled corner states splitting into two pairs appear in the square OTO bend structure owing to the nonsymmorphic PC lack of mirror symmetries. Finally, the topological robustness of the multimode interference effect of coupled edge and corner states against defects is demonstrated. Our results pave the way for guiding and trapping acoustic waves in topological nonsymmorphic heterostructures, whose multi-channel transmission capability can be employed for designing topological phononic filters, couplers and multiplexers.
The bicomplex tensor product and a bicomplex Choi theorem
Authors: Alpay Daniel , De Martino Antonino , Diki Kamal , Vajiac Mihaela
Published: August 2024

In this paper we extend the concept of tensor product to the bicomplex case and use it to prove the bicomplex counterpart of the classical Choi theorem in the theory of complex matrices and operators. The concept of hyperbolic tensor product is also discussed, and we link these results to the theory of quantum channels in the bicomplex and hyperbolic case.
Development of a sustainable polymer composite: enhancing properties of waste plastic with ground tire rubber reinforcement
Authors: Dasgupta Archisman , Sen Binayak , Dutta Prasenjit
Published: August 2024

The growing interest in utilizing waste for composite development has prompted investigations across social, economic, and environmental domains. This study focuses on utilizing recyclable waste plastic materials and micro-sized ground tire rubber (GTR) of varying sizes (600 μm, 300 μm, and 150 μm) to create a polymer matrix composite (PMC). Employing a thermal blending technique, the manufacturing process adjusts the composition ratios of polymer and GTR from 90:10 to 50:50. Subsequently, Energy Dispersive Spectroscopy (EDS) is utilized to analyze the PMC composition, while Fourier-transform infrared spectroscopy confirms functional group and chemical structure. The study demonstrates significant improvements in various properties upon adding GTR to High-Density Polyethylene (HDPE) and Low-Density Polyethylene (LDPE) composite materials. For HDPE-GTR composites, the melting temperature (Tm) ranged from 120.29 °C to 138.53 °C, crystallization temperature (Tc) from 102.84 °C to 127.14 °C, and enthalpy of melting (ΔHm) from 70.96 to 139.67 J g−1. Crystallinity (Xc) varied from 48.43% to 52.96%. In LDPE-GTR composites, Tm ranged from 106.08 °C to 129.57 °C, Tc from 90.27 °C to 112.20 °C, ΔHm from 75.59 to 142.53 J g−1, and Xc from 51.59% to 54.05%. Moreover, mechanical properties such as tensile strength, flexural modulus, and impact strength exhibited enhancements with GTR addition to the polymer matrix. These findings underscore the potential of sustainable waste utilization, advancing environmentally friendly and resource-efficient composite materials.
Au/Nb2O5 terahertz-gigahertz electro-optical filters designed for high frequency applications
Authors: Algarni Sabah E , Qasrawi A F , Khusayfan Najla M
Published: August 2024

Herein enhanced broad band filters are fabricated by deposing thin films of Nb2O5 onto glass and semitransparent Au nanosheets using the ion coating technique. Remarkable enhancement in the surface roughness of the films and in the visible and infrared light absorption by more than 270% and 750%, respectively, is achieved by coating the films onto Au nanosheets. Au nanosheets redshifted the energy band gap and initiated the free carrier absorption in the Nb2O5 films. As terahertz band filters, Au/Nb2O5 interfaces exhibited higher dielectric constant, higher optical conductivity and higher terahertz cutoff frequency values. Au/Nb2O5 optical filters showed terahertz resonator characteristics displaying six resonance modes two, three and one of which are dominant in the infrared, visible and ultraviolet ranges, respectively. On the other hand the impedance spectroscopy analyses for Au/Nb2O5/Au (ANA) filter showed microwave resonator characteristics with cutoff frequency values reaching 700 GHz for signal carriers of driving frequency of 1.65 GHz. ANA devices exhibited negative capacitance effect in a wide range of driving frequency domain. The features of the Au/Nb2O5 films demonstrate their potential for use as gigahertz-terahertz broad band electro-optical resonators suitable for high frequency applications.
Void-induced mechanisms in tensile behavior of nickel-based single crystal superalloys
Authors: Zheng Min , Bian Zhiao , Qu Dingfeng , Zhang Shengbin , Ren Xiaojun , Chen Weihua , Zhu Zongxiao
Published: August 2024

Void defects significantly impact the tensile properties of nickel-based single crystal superalloys. In this work, the dynamic response of void-included nickel-based single crystal superalloys under tensile loading was studied using molecular dynamics method. The effects of porosity and void size on the tensile behavior and the evolution of internal defects were explored from a microscopic perspective. The results indicate that the presence of voids promotes the development of internal dislocation defects and atomic phase transitions, especially in the initial stage of plastic deformation. The tensile strength decreases with increasing porosity. Plastic deformation and atomic phase transitions typically initiate between voids and continue until complete fracture, with shear strains and dislocation defects continuously concentrating around the voids. Notably, some HCP defect atoms distant from voids revert to FCC phase atoms during the tensile process, leading to a decrease in dislocation density. Additionally, the mode of fracture in the porous model is shear fracture, with shear strain and dislocation defects remaining at the fracture surface after complete fracture. The effects of void size on the tensile strength are relatively small. As the void size decreases, the shear strain bands in the models become more regular and the dislocation density decreases. However, the impact of small-sized voids on the material becomes increasingly evident with further stretching.
The Completeness of Accreting Neutron Star Binary Candidates from the Chinese Space Station Telescope
Authors: Shen Hao , Lan Shun-Yi , Meng Xiang-Cun
Published: August 2024

A neutron star (NS) has many extreme physical conditions, and one may obtain some important information about an NS via accreting neutron star binary (ANSB) systems. The upcoming Chinese Space Station Telescope (CSST) provides an opportunity to search for a large sample of ANSB candidates. Our goal is to check the completeness of the potential ANSB samples from CSST data. In this paper, we generate some ANSBs and normal binaries under the CSST photometric system by binary evolution and binary population synthesis method and use a machine learning method to train a classification model. Although the Precision (94.56%) of our machine learning model is as high as before study, the Recall is only about 63.29%. The Precision/Recall is mainly determined by the mass transfer rate between the NSs and their companions. In addition, we also find that the completeness of ANSB samples from CSST photometric data by the machine learning method also depends on the companion mass and the age of the system. ANSB candidates with a low initial mass companion star (0.1 M
⊙ to 1 M
⊙) have a relatively high Precision (94.94%) and high Recall (86.32%), whereas ANSB candidates with a higher initial mass companion star (1.1 M
⊙ to 3 M
⊙) have similar Precision (93.88%) and quite low Recall (42.67%). Our results indicate that although the machine learning method may obtain a relatively pure sample of ANSBs, a completeness correction is necessary for one to obtain a complete sample.
A highly sensitive ratiometric near-infrared nanosensor based on erbium-hyperdoped silicon quantum dots for iron(Ⅲ) detection
Authors: Wang Kun , Lai Wenxuan , Ni Zhenyi , Yang Deren , Pi Xiaodong
Published: August 2024

Ratiometric fluorescent detection of iron(Ⅲ) (Fe3+) offers inherent self-calibration and contactless analytic capabilities. However, realizing a dual-emission near-infrared (NIR) nanosensor with a low limit of detection (LOD) is rather challenging. In this work, we report the synthesis of water-dispersible erbium-hyperdoped silicon quantum dots (Si QDs:Er), which emit NIR light at the wavelengths of 810 and 1540 nm. A dual-emission NIR nanosensor based on water-dispersible Si QDs:Er enables ratiometric Fe3+ detection with a very low LOD (0.06 μM). The effects of pH, recyclability, and the interplay between static and dynamic quenching mechanisms for Fe3+ detection have been systematically studied. In addition, we demonstrate that the nanosensor may be used to construct a sequential logic circuit with memory functions.
A mechanically coupled MEMS filter with high-Q width extensional mode resonators
Authors: Wang Wei , Liu Wenli , Zhao Junyuan , Niu Bo , Wu Zeyu , Zhu Yinfang , Yang Jinling , Yang Fuhua
Published: August 2024

This work presents a novel radio frequency (RF) narrowband Si micro-electro-mechanical systems (MEMS) filter based on capacitively transduced slotted width extensional mode (WEM) resonators. The flexibility of the plate leads to multiple modes near the target frequency. The high Q-factor resonators of around 100 000 enable narrow bandwidth filters with small size and simplified design. The 1-wavelength and 2-wavelength WEMs were first developed as a pair of coupled modes to form a passband. To reduce bandwidth, two plates are coupled with a λ-length coupling beam. The 79.69 MHz coupled plate filter (CPF) achieved a narrow bandwidth of 8.8 kHz, corresponding to a tiny 0.011%. The CPF exhibits an impressive 34.84 dB stopband rejection and 7.82 dB insertion loss with near-zero passband ripple. In summary, the RF MEMS filter presented in this work shows promising potential for application in RF transceiver front-ends.
Quasilinear theory and modelling of gyrokinetic turbulent transport in tokamaks
Authors: Staebler G. , Bourdelle C. , Citrin J. , Waltz R.
Published: August 2024

The theory, development, and validation of reduced quasilinear models of gyrokinetic turbulent transport in the closed flux surface core of tokamaks is reviewed. In combination with neoclassical collisional transport, these models are successful in accurately predicting core tokamak plasma temperature, density, rotation, and impurity profiles in a variety of confinement regimes. Refined experimental tests have been performed to validate the predictions of the quasilinear models, probing changes in the dominant gyrokinetic instabilities, as reflected in fluctuation measurements, cross-phases, and transport properties. These tests continue to produce a deeper understanding of the complex mix of instabilities at both electron and ion gyroradius scales.
Damage evolution in Plasma Facing Materials by a sequential multiscale approach
Authors: Lo Presti G. , La Magna A.
Published: August 2024

Describing the time evolution of Plasma Facing Materials (PFMs), through quantitative evaluations of erosion, roughness, and physical properties degradation, is one of the difficult challenges to reach the goal of efficient energy production by nuclear fusion. To follow all the aging-connected physical and chemical phenomena through their characteristic dimensional scale, and to estimate the PFM microstructural transformation over time, we propose a predictive sequential multiscale methodology, consisting of two database-provided coupled codes. The first is a time-dependent, volume-averaged, plasma simulator which describes completely this system in terms of thermodynamics, composition and evaluation of the sheath potential. Plasma solutions are geometrically rearranged by adding surface reactions and 3D geometric features. To increase sensitivity, plasma information is provided to the second code as an initial condition. Such a code is a 3D kinetic Monte Carlo in-cell algorithm for the nano-scale erosion simulation describing the PFM interactions through an extendable set of physical phenomena, such as sticking, sputtering, ion enhanced removals and ion penetration. In this paper, we perform simulations for the case of study of Hydrogen (H) plasmas produced in linear devices, reaching the quasi-atomic detail of the plasma induced material modification of tungsten (W) as PFM.
Overview of recent results from the ST40 compact high-field spherical tokamak
Authors: McNamara S.A.M. , Alieva A. , Anastopoulos Tzanis M.S. , Asunta O. , Bland J. , Bohlin H. , Buxton P.F. , Colgan C. , Dnestrovskii A. , du Toit E. , Fontana M. , Gemmell M. , Gryaznevich M.P. , Hakosalo J. , Hardman M.R. , Harryman D. , Hoffman D. , Iliasova M. , Janhunen S. , Janky F. , Lister J.B. , Lowe H.F. , Maartensson E. , Marsden C. , Medvedev S.Y. , Mirfayzi S.R. , Moscheni M. , Naylor G. , Nemytov V. , Njau J. , O’Gorman T. , Osin D. , Pyragius T. , Rengle A. , Romanelli M. , Romero C. , Sertoli M. , Shevchenko V. , Sinha J. , Sladkomedova A. , Sridhar S. , Stirling J. , Takase Y. , Thomas P.R. , Varje J. , Vekshina E. , Vincent B. , Willett H.V. , Wood J. , Wooldridge E. , Zakhar D. , Zhang X. , Battaglia D. , Bertelli N. , Bonofiglo P.J. , Delgado-Aparicio L.F. , Duarte V.N. , Gorelenkov N.N. , de Haas M. , Kaye S.M. , Maingi R. , Mueller D. , Ono M. , Podesta M. , Ren Y. , Trieu S. , Delabie E. , Gray T.K. , Lomanowski B. , Unterberg E.A. , Marchuk O. ,   the ST40 Team
Published: August 2024

ST40 is a compact, high-field (

B

T
0

⩽
2.1

T

) spherical tokamak (ST) with a mission to expand the physics and technology basis for the ST route to commercial fusion. The ST40 research programme covers confinement and stability; solenoid-free start-up; high-performance operating scenarios; and plasma exhaust. In 2022, ST40 obtained central deuterium ion temperatures of

9.6
±
0.4
 
keV

, demonstrating for the first time that pilot plant relevant ion temperatures can be reached in a compact, high-field ST. Analysis of these high-ion temperature plasmas is presented, including a summary of confinement, transport and microstability characteristics, and energetic particle instabilities. Recent scenario development activities have focused on establishing diverted H-mode plasmas across a range of toroidal fields and plasma currents, along with scenarios with high non-inductive current fractions. In future operations, beginning in 2025, a 1 MW dual frequency (104/137 GHz) electron cyclotron (EC) system will be installed to enable the study of EC and electron Bernstein wave plasma start-up and current drive. Predictive modelling of the potential performance of these systems is presented.
Effect of SiO2 concentration on the mechanical and anticorrosive properties of the hybrid PMMA/SiO2 coating synthesized in situ by sol-gel process.
Authors: Reyes-Tesillo Bryanda G. , López-Campos Jevet E. D. , Mojica-Gómez José , Ferrer-Pérez Jorge A. , Hernández-Padrón Genoveva
Published: August 2024

Anti-corrosive evaluation of a hybrid polymethylmethacrylate (PMMA) with silica particles (SiO2) is presented, the hybrid (PMMA-SiO2) was synthetized in situ by sol-gel process. The SiO2 particles were embedded into to matrix PMMA at different concentrations. The hybrid structure of the coatings was characterized and observed with Fourier Transform Infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The deposition of the hybrid in aluminum 7075-T6 (Al7075) substrates was made with the blade coating technique, measuring wet and dry film thickness. For the preparation of the hybrid, PMMA was used without any type of curing, which allowed us to save resources. All tests were performed according to American Society for Testing and Materials (ASTM international) standards. The incorporation of SiO2 to concentrations significantly improved the mechanical and anti-corrosive results. PMMA-SiO2 coating, once deposited on the surface of Al7075 plates, has been tested inside a salt fog chamber (CNS) operated under accelerated conditions. They were improved up to 920 h its corrosion resistance. The abrasion tests had an increase of 50%, its hardness up to 4H and the wear index improved by 50% compared with the hybrids with minor SiO2 concentration, which shows that a higher concentration of SiO2 particles has a higher performance of the coating.
Radiofrequency and optical satellite link budgeting calculator
Authors: Rosas-Palacios A. , Casillas-Aviña G. E. , Yáñez-Casas G. A. , López-Balcázar C. A. , Hernández-Gómez J. J.
Published: August 2024

Satellite communications represent one of the most widely used communication systems nowadays. From the 50’s of 20th century up to the present, the demand for satellite services has increased rapidly, so the need to design and implement reliable, up-to-date systems that meet the needs of users is increasingly imperative. Technological progress also implies a better use of the radio spectrum and the incorporation of benefits in terms of transmission performance. Traditionally, satellite systems have been implemented in the range corresponding to radio frequency, and more recently, special attention has been paid to the exploration of the spectrum corresponding to optical communications, due to the superior benefits that it offers, despite the set of challenges that its implementation represents. Such advances demand the greatest certainty of operation even from the conception and design stage of the transmission system, since satellite communications are not prone to constant changes and maintenance. The calculation process known as link budget is a tool present in the design of any wireless communications system, and its results determine the efficiency and reliability of the design. However, due to the large number of manufacturers and operators, as well as considering the novelty of using high-performance optical systems, it is difficult to stick to a single method or even to point out one as totally reliable and simple to use. With the purpose of expediting the calculation of link budgets, there are various computational tools that allow this process to be carried out. However, these tools carry the problem of poor compatibility, differences and a low degree of reliability and ease of use. In the present work, the construction and use of a web application is proposed that includes the link budget calculation process for both radio and optical satellite systems, flexible, simple, user-friendly, compatible, and mainly, abode to standardised and documented models for provide reliability and accuracy.
Introduction to thermal control design process for CubeSats in Mexico
Authors: Ferrer-Perez J A , Gaviria-Arcila D , Romo-Fuentes C , Chávez-Moreno R G , Ramírez-Aguilar J A , López-Parra M , Bermudez-Reyes B , Farah-Simón A , Zuñiga-Contreras D , Reyes-Tesillo B G , Sánchez-Guzmán J A , Valdés-Galicia J F
Published: August 2024

CubeSats are a popular type of spacecraft categorized as nanosatellites. In 1999, Professors first developed these devices at California Polytechnic State University and Stanford University to offer an affordable and accessible experience to students. Data information updated up to May 31st, 2023, shows that 2286 Nanosats have been launched, where 2105 were CubeSats. Moreover, 82 countries have nanosats, whereas Latin America has 44 CubeSat. The fact that Mexico just 5 launched 5 CubeSats is a consequence of the complicated space sector ecosystem in the nation that combines lack of funding and, more importantly, the absence of ¨know-how¨ design space missions from scratch. This manuscript reviews the system engineering methodology used to develop space missions, according to NASA discussing a particular methodology for CubeSat Missions. Next, a CubeSat data trend is shown, followed by a general description of its subsystems. Afterward, the design process activities of the Thermal Control Subsystem (TCS) based on the “NASA Systems Engineering Processes and Requirements” and “Thermal analysis handbook is described. The TCS is often underestimated and confused to implement. For this reason, a design methodology for the TCS accepted to Mexico context is proposed. Finally, the conclusions are presented.
Design of a bioreactor as a vital biological support for testing microalgae cultures in the stratosphere.
Authors: Hernández González Umanel Azazael , Mirelez Delgado Flabio Dario , Moreno Castro Addried Samir , Correa Aguado Hans Christian , Alvarado Alvarado Carlos Arturo , Escareño Fernández Joel Alejandro , Castillo Diego Osorio , Troncoso Jorge Flores
Published: August 2024

In the present, the proposal for the design of an autonomous, light and completely closed bioreactor that will orbit in the stratosphere is developed, capable of promoting the growth of microalgae, specifically of the species: Chlorella vulgaris. The document will address the development of the relevant background information related to this proposal, which will support the bases and certain decisions described in the work, as well as the concepts that will define the theoretical framework for the identification of primary and secondary sources that allow to know, design and develop the proposed. In order to achieve a system capable of performing mixing and recirculation operations, necessary to promote the transfer of mass and energy, as well as the adequate distribution of light, the different existing bioreactor models and their most significant differences will be analyzed. For this work, only five of the nine stages of the mechatronic design methodology are covered: identification of needs, analysis of the problem, preparation of specifications, generation of possible solutions, and selection of the appropriate solution. The missing stages; detailed design, production of working drawings, prototype construction, and testing are underway.
A comparative study of acoustic and ultrasonic nondestructive testing for evaluating melon quality
Authors: Khuriyati N , Kasih A N , Perdana M R A , Izdihar F Y , Falah M A F , Wagiman
Published: August 2024

Melon (Cucumis melo L.) is a high-value agricultural commodity known worldwide for its sweet taste and crisp flesh texture, which are important factors for quality and consumer acceptance. Unfortunately, quality testing and determining the optimal harvest time for achieving desired melon characteristics are traditionally performed through destructive methods. The aim of this study was to explore the potential of acoustic and ultrasonic tests for predicting the physicochemical properties of Honey Globe melons (Cucumis melo L. var. inodorus). A total of 100 melon samples were used in this study. For the nondestructive ultrasonic testing, attenuation values served as its variable, whereas in acoustic testing, variables included frequency, magnitude, short-term energy, and zero-moment. Fruit’s flesh firmness and total soluble solids (TSS) as physicochemical quality properties were determined using destructive tests. The calibration phase involved 80 melon samples, employing a K-Fold Cross Validation approach with ten folds, done on Partial Least Square Regression (PLS) modeling. Another 20 melon samples were used for blind testing. Reliability evaluation was done on key metrics, consisting of R2 values, RMSEC (Root Mean Square Error of Calibration), RMSECV (Root Mean Square Error of Cross-Validation), RMSEP (Root Mean Square Error of Prediction), and RPD (Ratio of Performance to Deviation). Analysis results on these metrics collectively support the conclusion that both ultrasonic and acoustic methods exhibit their potential to predict the firmness properties of melon fruits. The best evaluation result that has been conducted for the ultrasonic test uses attenuation, age, and density as predictors to predict fruit firmness, with R2 = 0.763 and RPD = 2.945, while the acoustic test achieved the best result with magnitude used as a predictor to predict fruit firmness with R2 = 0.718 and RPD = 2.230. However, evaluation metrics on the prediction of total soluble solids for both nondestructive tests were still not good enough for application with low R2 and RPD value.
The conceptual model of Indonesian palm oil supply chain based on blockchain
Authors: Adisetya E , Sunardi  , Gunawan S
Published: August 2024

Indonesia is the world’s largest producer and consumer of palm oil. However, the palm oil supply chain faces numerous challenges related to actors, traceability, transparency, and sustainability. To address these issues, a conceptual model for a blockchain-based palm oil supply chain in Indonesia is proposed. The model aims to leverage the decentralized and immutable nature of blockchain technology. It incorporates components such as smart contracts, distributed ledgers, and data sharing mechanisms to enhance traceability, transparency, and sustainability in the palm oil supply chain. The research utilized the SSM (Soft System Methodology) and CATWOE (Customer, Actor, Transformation, Worldview, Owner, Environment) methodologies. The actors involved in the palm oil supply chain include smallholders, plantation companies, third-party suppliers, middlemen, traders, palm oil mills, refineries, distributors, retailers, and consumers. The blockchain conceptual model is structured based on a sustainable supply chain model that considers economic, social, and environmental aspects. Blockchain transactions regulate the process of supply chain actors, while stakeholders such as the government, financial institutions, palm oil research organizations, NGOs, and consumers are involved. The blockchain-based supply chain model is expected to address the key issues of the palm oil supply chain, aiming for a sustainable supply chain system. By implementing this model, it is anticipated that the palm oil industry can achieve greater accountability, transparency, and environmental sustainability.
Optimizing the drying process with the surface response method for snap beans, sweet corn, and carrots
Authors: Kumalasari R , Anggraeny S , Ikrawan Y , Indrianti N , Sholichah E , Ratnawati L
Published: August 2024

Vegetables contain many nutrients that are susceptible to loss when dried. Pre-treatment is needed to reduce nutrient loss during drying. This research aims to determine optimal pre-treatment and drying conditions for dried vegetables. Optimization using the D-optimal response surface method for snap beans, carrots, and sweet corn. The optimized process conditions are drying temperature (45°C, 50°C, 55°C); blanching technique at 75°C (immersion, steaming); freezing treatment (with freezing -20°C 24 hours, without freezing); and type of dryer (cabinet dryer, dehydrator). The research results show that immersion blanching (75°C), freezing (-20°C, 24 hours), and cabinet dryer type at 50°C are the best conditions for processing dried snap beans. The best method for drying sweet corn is immersion blanching (75°C), freezing (-20°C, 24 hours), and drying in a dehydrator-type drying at 50°C. Immersion blanching (75°C), freezing (-20°C, 24 hours), and dehydrator-type dryer at 55°C are the best methods for drying carrots.