bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing diffuser performance using transverse grooves to delay flow separation
Authors: Bertini Amedeo Cesare Giovanni , Lunghi Gianmarco , Boffadossi Maurizio , Fenili Simone , Lombardi Giovanni , Maganzi Marco , Mariotti Alessandro
Published: October 2024

A flow-control method is applied to enhance the efficiency and flow homogeneity of three-dimensional diffusers used in open-jet wind tunnels. Suitably shaped grooves are introduced in the diffuser diverging walls. The grooves promote the relaxation of the non-slip condition along the streamlines bounding the small recirculation regions forming passively inside the grooves. That reduces momentum losses and results in a downstream boundary layer with higher momentum, which is more separation-resistant. The proposed flow-control device has been successfully validated for plane diffusers [Mariotti et al., “Separation control and efficiency improvement in a 2D diffuser by means of contoured cavities,” Eur. J. Mech.-B 41, 138–149 (2013); and Mariotti et al., “Control of the turbulent flow in a plane diffuser through optimized contoured cavities,” Eur. J. Mech.-B 48, 254–265 (2014)]. In this study, we examined circular and square-section diffusers with different degrees of flow separation. Given that the investigated diffusers are part of open-jet wind tunnels, the entire wind tunnel geometry was included in the numerical simulation. The grooves significantly enhanced performance in circular diffusers by reducing the extent of separation and promoting an axisymmetric and spatially uniform flow. However, negligible benefits were observed for square-section diffusers. In these cases, since flow separation originates from one of the four inclined edges of the diffuser, placing grooves along the diverging walls does not effectively reduce the separation extent. Nonetheless, the grooves become effective again in diffusers with rectangular cross sections of high aspect ratio.
Vibrational squeezing via spin inversion pulses
Authors: Krass Marc-Dominik , Prumbaum Nils , Pachlatko Raphael , Degen Christian L. , Eichler Alexander
Published: October 2024

Magnetic resonance force microscopy (MRFM) describes a range of approaches to detect nuclear spins with mechanical sensors. MRFM has the potential to enable magnetic resonance imaging with near-atomic spatial resolution, opening up exciting possibilities in solid state and biological research. In many cases, the spin-mechanics coupling in MRFM is engineered with the help of periodic radio frequency pulses. In this paper, we report that such pulses can result in unwanted parametric amplification of the mechanical vibrations, causing misinterpretation of the measured signal. We show how the parametric effect can be canceled by auxiliary radio frequency pulses or by appropriate post-correction after careful calibration. Future MRFM measurements may even make use of the parametric amplification to reduce the impact of amplifier noise.
Low temperature dynamics of H + HeH+→ H2+ + He reaction: On the importance of long-range interaction
Authors: Sahoo Jayakrushna , Bossion Duncan , González-Lezana Tomás , Talbi Dahbia , Scribano Yohann
Published: October 2024

While the growing realization of the importance of long-range interactions is being demonstrated in cold and ultracold bimolecular collision experiments, their influence on one of the most critical ion-neutral reactions has been overlooked. Here, we address the non-Langevin abrupt decrease observed earlier in the low-energy integral cross-sections and rate coefficients of the astrochemically important H + HeH+→ H2+ + He reaction. We attribute this to the presence of artificial barriers on existing potential energy surfaces (PESs). By incorporating precise long-range interaction terms, we introduce a new refined barrierless PES for the electronic ground state of HeH2+ reactive system, aligning closely with high-level ab initio electronic energies. Our findings, supported by various classical, quantum, and statistical methods, underscore the significance of long-range terms in accurately modeling reactive PESs. The low-temperature rate coefficient on this new PES shows a substantial enhancement as compared to the previous results and aligns with the Langevin behavior. This enhancement could noticeably affect the prediction of HeH+ abundance in early Universe condition.
Functional and transcriptional regulation of the anthocyanidin acyl modifier gene Gs5AT of Gentiana sino-ornata
Authors: Meng Han , Chen Siqi , Wu Yanmei , Jin Xuehua
Published: October 2024

The Chinese gentian, Gentiana sino-ornata produces brilliant blue flowers. To investigate the biological function and transcriptional regulation mechanism of the anthocyanin 5-O-acyltransferase gene (Gs5AT) in the corolla, it is beneficial to analyse the mechanism of blue flower colour presentation. In this investigation, we obtained the CDS and promoter sequences of the gene Gs5AT. Yeast one-hybrid experiments were used to identify the transcription factor GsbHLH7 that activates the gene Gs5AT. According to quantitive reverse transcription polymerase chain reaction analysis, the expression of the gene Gs5AT was significantly and positively correlated with the gene GsbHLH7. The colour phenotype of the flowers was significantly altered by the virus-induced gene silencing transduction of Gs5AT and GsbHLH7, with GsbHLH7 silencing producing more pronounced changes in the corolla colour than Gs5AT. The expression of GsF3′5′H, GsDFR, GsANS, Gs3GT, and Gs5GT all fell to varying degrees after GsbHLH7 silencing, indicating that GsbHLH7 may regulate transcription of these genes as well as Gs5AT. The results of this study indicate that Gs5AT was positively regulated by the GsbHLH7, and thus affects the colour presentation of the blue corolla.
Threats to personal control fuel similarity attraction
Authors: Ma Anyi , Paek Jessica J. W. , Liu Fangzhou , Kim Jae Yun
Published: October 2024

We propose that experiencing a lack of personal control will increase people’s preferences for self-similar others and that this effect would be explained by a greater need for structure. Our hypotheses received support across 11 longitudinal, experimental, and archival studies composed of data from 60 countries (5 preregistered studies,
N
= 90,216). In an analysis of cross-country archival data, we found that respondents who indicated a lower sense of personal control were less likely to prefer to live with neighbors who had a different religion, race, or spoke a different language (Study 1). Study 2 found that participants who perceived lower (vs. higher) personal control indicated greater liking for coworkers who they perceived to be more self-similar across a wide range of characteristics (e.g., gender, personality). Studies 3a and 3b, two live-interaction experiments conducted in the United States and China, provided additional causal evidence for control-motivated similarity attraction. A causal experimental chain (Studies 4a to 4c) and a manipulation-of-mediation-as-a-moderator study (Study 5) provided evidence for the mediating effects of the need for structure. Study 6, a longitudinal study with Chinese employees, found that workers who reported perceiving a lower (vs. higher) sense of personal control preferred more self-similar coworkers, and this effect was mediated by a greater desire for structure. Finally, exploring downstream consequences, Studies 7a and 7b found that control-motivated similarity attraction was associated with a greater preference for homogenous (vs. diverse) groups. These findings highlight how the fundamental motive for personal control shapes the structure of social life.
Modeling the population-level impact of a third dose of MMR vaccine on a mumps outbreak at the University of Iowa
Authors: Park Sang Woo , Lawal Tomi , Marin Mona , Marlow Mariel A. , Grenfell Bryan T. , Masters Nina B.
Published: October 2024

Mumps outbreaks among fully vaccinated young adults have raised questions about potential waning of immunity over time and need for a third dose of the measles, mumps, rubella (MMR) vaccine. However, there are currently limited data on real-life effectiveness of the third-dose MMR vaccine in preventing mumps. Here, we used a deterministic compartmental model to infer the effectiveness of the third-dose MMR vaccine in preventing mumps cases by analyzing the mumps outbreak that occurred at the University of Iowa between August 24, 2015, and May 13, 2016. The modeling approach further allowed us to evaluate the population-level impact of vaccination by different timing in relation to the start of the outbreak and varied coverage levels, and to account for potential sources of bias in estimating vaccine effectiveness. We found large uncertainty in vaccine effectiveness estimates; however, our models showed that early introduction of a third dose of MMR vaccine during a mumps outbreak can be effective in preventing transmission. School holidays, such as the winter break, likely played important roles in preventing mumps transmission.
Goblet cell differentiation subgroups in colorectal cancer
Authors: Abdullayeva Gulnar , Liu Haoyu , Liu Ta-Chun , Simmons Alison , Novelli Marco , Huseynova Irada , Lastun Viorica L. , Bodmer Walter
Published: October 2024

The poor prognosis of relatively undifferentiated cancers has long been recognized, suggesting that selection against differentiation and in favor of uncontrolled growth is one of the most powerful drivers of cancer progression. Goblet cells provide the mucous surface of the gut, and when present in colorectal cancers (CRC), the cancers are called mucinous. We have used the presence of MUC2, the main mucous product of goblet cells, and an associated gene product, TFF3, to classify a large panel of nearly 80 CRC-derived cell lines into five categories based on their levels of MUC2 and TFF3 expression. We have then shown that these five patterns of expression can be easily identified in the direct analysis of tumor specimens allowing a much finer characterization of CRCs with respect to the presence of goblet cell differentiation. In particular, about 30% of all CRCs fall into the category of expressing TFF3 but not MUC2, which has not previously been acknowledged. Using the cell line data, we suggest that there are up to 12 genes (
MUC2, TFF3, ATOH1, SPDEF, CDX1, CDX2, GATA6, HES1, ETS2, OLFM4, TOX3,
and
LGR5
) that may be involved in selection against goblet cell differentiation in CRC by changes in methylation rather than mutations. Of these,
LGR5
, which is particularly associated with lack of goblet cell features, may function in the control of differentiation rather than direct control of cell growth, as has so far mostly been assumed. These results emphasize the importance of methylation changes in driving cancer progression.
Using CRISPR-Cas9 genome editing to enhance disease resistance in banana
Authors: Tripathi Jaindra Nath , Tripathi Leena
Published: October 2024

Bananas and plantains (
Musa
spp.) are leading global fruit crops, cultivated in over 150 countries and several island nations and serving as fruit and staple food in tropical and subtropical regions. Notwithstanding their economic importance, banana production is hindered by pests, diseases, and climatic challenges, resulting in significant yield gaps and post-harvest losses. Conventional breeding methods are time-consuming and labor-intensive due to the 15–18 months long life cycle and seedless nature of the edible crop, while transgenic approaches face regulatory, public acceptance, and sociopolitical hurdles. The advent of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR-Cas9) technology offers a precise, targeted, and efficient tool for genetic mutation derived from the bacterial antiviral defense system. Researchers are exploring CRISPR-Cas9 to develop banana varieties resistant to diseases and pests, exhibit higher yields, and possess enhanced nutritional profiles. The well-annotated complete banana genome, combined with advanced regeneration and transformation systems, facilitates the application of CRISPR-Cas9 technology. This innovative approach promises to create superior banana cultivars that benefit consumers and farmers, addressing critical challenges in banana production and contributing to global food security. This review article discusses the challenges in banana production, including biotic and abiotic constraints, and explores recent advancements in genome editing.
Fluorescence lifetime sorting reveals tunable enzyme interactions within cytoplasmic condensates
Authors: Fahim Leyla E. , Marcus Joshua M. , Powell Noah D. , Ralston Zachary A. , Walgamotte Katherine , Perego Eleonora , Vicidomini Giuseppe , Rossetta Alessandro , Lee Jason E.
Published: October 2024

Ribonucleoprotein (RNP) condensates partition RNA and protein into multiple liquid phases. The multiphasic feature of condensate-enriched components creates experimental challenges for distinguishing membraneless condensate functions from the surrounding dilute phase. We combined fluorescence lifetime imaging microscopy (FLIM) with phasor plot filtering and segmentation to resolve condensates from the dilute phase. Condensate-specific lifetimes were used to track protein–protein interactions by measuring FLIM–Förster resonance energy transfer (FRET). We used condensate FLIM-FRET to evaluate whether mRNA decapping complex subunits can form decapping-competent interactions within P-bodies. Condensate FLIM-FRET revealed the presence of core subunit interactions within P-bodies under basal conditions and the disruption of interactions between the decapping enzyme (Dcp2) and a critical cofactor (Dcp1A) during oxidative stress. Our results show a context-dependent plasticity of the P-body interaction network, which can be rewired within minutes in response to stimuli. Together, our FLIM-based approaches provide investigators with an automated and rigorous method to uncover and track essential protein–protein interaction dynamics within RNP condensates in live cells.
Mass octupole and current quadrupole corrections to gravitational wave emission from close hyperbolic encounters
Authors: Roskill Alexander , Caldarola Marienza , Kuroyanagi Sachiko , Nesseris Savvas
Published: October 2024

In this paper, we study the next-to-leading order corrections in the mass multipole expansion, i.e. the mass octupole and current quadrupole, to gravitational wave production by close hyperbolic encounters of compact objects. We find that the signal is again, as in the simple quadrupole case, a burst event with the majority of the released energy occurring during the closest approach. In particular, we investigate the relative contribution to the power, both in the time and frequency domains, and total energy emitted by each order in the mass multipole expansion in gravitational waves. To do so, we include in the quadrupole term its first order post-Newtonian correction, giving this a contribution to the power of the same order as that of the mass octupole and the current quadrupole. We find specific configurations of systems where these corrections could be important and should be taken into account when analysing burst events.
Paper-based thermoelectric generators for viable waste heat harvesting
Authors: Das Surajit , Mondal Bhargab Prasad , Datta Anuja
Published: October 2024

There is currently an ongoing surge of effort toward sustainable, self-powered, scalable clean energy sources for next generation wireless electronics, IoT sensors and wearable microelectronics. Globally, almost two-thirds of the converted energy is lost as heat energy during the processes of power generation and energy conversion from fossil fuels and other traditional energy sources. Thermoelectric (TE) generators (TEG) add a robust solution toward efficiently harvesting low gradient waste heat energy into extractable micropower, offering scalable and viable choices to generate electricity ranging from excess heat generated in solar panels, automobile exhaust and factory heat outlets to day-to-day human activities, domestic electrical equipment and electronics. Paper-based TEGs (PTEGs) have become an area of immense research activity in the last few years, mainly because of the environmentally friendly, flexible, economic, and easy industry translatable nature of paper/cellulose. Even though PTEG’s output performance still lags behind the performance of other flexible TEGs, rapid research directions toward materializing PTEG design, and including more varieties of TE materials and methods are having a large impact upon further PTEG performance optimization. This review gives a concise overview of recent results, discussing the progress, advantages and potential barriers in PTEG research with a view to predicting future strategies and goals to increase their functionality in the thermal energy harvesting market.
Degradation of crystalline silicon solar cells caused by lightning induced impulse surge
Authors: Zhong Xiao , Zhang Jiahao , Liao Zitao , Wu Rong , Wang Shuaijie , Bin Feng , Sun Qiuqin
Published: October 2024

Crystalline silicon (c-Si) solar cells are connected in series to form photovoltaic modules, which are installed in wide-open areas. They are exposed to lightning electromagnetic (EM) interference at high risk. The lightning EM field can induce an impulse surge in the loop of the solar-cell string, and c-Si solar cells are prone to damage. To study the effect of lightning surge on monocrystalline silicon cells and polycrystalline silicon cells, impulse voltage tests are conducted. Semiconductor structures of c-Si solar cells after testing are observed using scanning electron microscopy. The results indicate that the lightning surge will generate some cracks and defects in the P–N junction. Under a strong electric field, the N-type emitter layer and the grain boundary can be destroyed, which contributes to the degradation of the c-Si solar cell. Compared to monocrystalline silicon cells, polycrystalline silicon cells can withstand greater forward lightning surge; however, their maximum reverse lightning surge is relatively low.
Temperature tunable ultra-wideband absorber based on ionic liquid
Authors: Yang Fulong , Wang Dayu , Wei Jinyan , Shi Zhinan , Guo Zhitao , Wang Teng , Zhang Yongxia , Zhou Jinjin , Wu Feng
Published: October 2024

In this paper, a temperature tunable ultra-wideband absorber based on ionic liquid is proposed for the microwave frequency band. The absorber consists of a band-resistive frequency selective surface, a 3D resin cavity vessel, and an ionic liquid ([EMIm][N(CN)2]) layer. Numerical simulation analysis shows that the absorptivity is more than 90% and a relative bandwidth is 113.04% in the range of 7.5–27 GHz. Meanwhile, the absorber absorptivity has different tuning effects in different frequency bands with the change of temperature. Along with the temperature going up, the absorptivity decreases in the low-frequency band of 6.5–14 GHz, the absorptivity increases in the high-frequency band of 28 GHz–40 GHz. It is worth mentioning that the proposed ionic liquid-based absorber has the characteristics of wide incidence angle and polarization insensitivity. Finally, the temperature tunable absorber model based on ionic liquid is fabricated by 3D printing technology. The experimental results are consistent with the simulation results, demonstrating that the absorber is practically feasible. In summary, the absorber achieves a wide frequency tuning range, which gives it great potential application prospects in fields such as frequency-selective thermal radiators.
Stereo disparity estimation based on Siamese network
Authors: Zhou Zhiyu , Ni Jie , Hu Yanjun , Wang Yaming
Published: October 2024

This paper proposes an approach for estimating stereo disparity based on a Siamese network. The existing Top-k disparity regression strategy may overlook the true disparity at object edges. To address this issue, an additional maximum disparity estimation value is introduced to optimize the Top-k strategy, creating the Top-k+ strategy. Furthermore, this research improves the MobileNetv2 (MV2) block by introducing an attention mechanism in the frequency domain, resulting in a more efficient FMV2 block that extracts high-frequency information such as textures and edges. Considering the excellent performance of the gated recurrent unit (GRU) in disparity optimization, the algorithm adopts an iterative optimization method based on GRU. Comparative studies pertaining to the Scene Flow, KITTI 2015, and ETH3D benchmark datasets show outstanding results in disparity estimation, with an end-point error of 0.58 pixels on the Scene Flow dataset, a D1-all error of 1.67% on the KITTI 2015 dataset, and an average disparity error of 0.22 pixels on the ETH3D dataset. Compared to other GRU-based iterative optimization algorithms, the proposed method not only exhibits significant performance advantages but also demonstrates a lightweight design.
A novel wafer defocus measurement method for spot-scanning imaging system using laser triangulation
Authors: Zhou Zuoda , Qu Dingjun , Ding Ruizhe , Luo Haiyan , Xiong Wei , Li Zhiwei , Jin Wei , Ru Yu , Jia Shihao , Hong Jin
Published: October 2024

For spot scanning dark-field scattering technology, the defocus caused by the change in wafer surface height decreases the defect detection rate and size measurement repeatability. The demand for accurately and rapidly measuring the wafer surface height online is becoming increasingly urgent. The defect detection system integrates scattering, reflection, film thickness, and topography defect detection channels. The integration of laser-triangulation-based defocus measurement into the bright-field optical path is proposed. The laser beam is directed onto the surface of the wafer, and the reflected light is transmitted through a lens onto the photosensitive surface of a four-quadrant detector. This detector captures both the strength and position of the reflected signal simultaneously. In this paper, a triangulation-modified model is established to obtain the height of each inspection spot on the wafer surface through the position signal of the reflected image. When the signal-to-noise ratio of the simulated reflection image position is 20 dB, the signal-to-noise ratio of the height measurement resolved by the triangulation-modified model is 41 dB, and the measurement error is less than 0.2 μm, indicating that the model has a noise suppression effect. The spot-scanning imaging system is established, and the height measurement results of the triangulation measurement model are verified using a laser interferometer. Within the travel range of 69 μm, the system has a measurement accuracy better than ±1 μm and a measurement repeatability better than ±0.2 μm, which meet the measurement requirements of the spot-scanning imaging system. The system is utilized for defect detection and defocus measurement of the wafer surface, along with the motion mechanism, to accurately and rapidly obtain the height distribution of the wafer surface.
Dynamic strain distribution monitoring and fatigue damage analysis on a 100 kW wind turbine blade based on field aerodynamic measurements
Authors: Zhang Pan , Zhu Zeng , Guo Xia , Zhang Lei , Wu Guangxing
Published: October 2024

Operation and maintenance (O&M) costs can account for 10%–20% of the total costs of electricity for a wind project. Structural health monitoring method is a form of preventive maintenance consisting of regular monitoring of the wind turbine components to detect potential faults. The strain measurements on the blades are typically used for load monitoring and damage detection, but only obtain a small amount of concentrated load information. In this work, a strain distribution monitoring method was proposed and validated based on aerodynamic measurements in the field. Then the contribution and evolution of the strain distribution from the aerodynamic load, gravity load, inertial load, and centrifugal load in the complex start-up process of the wind turbine were analyzed. The results shows that the mean value of the synthetic strain is mainly determined by the aerodynamic load and the centrifugal load, while the fluctuation amplitude is mainly determined by the gravity and the aerodynamic load. Furthermore, the fatigue damage of the blade root was evaluated based on strain extrapolation, rainflow cycle-counting algorithm, Goodman diagram and Miner’s linear superposition principle. It is found that the fatigue damage is generally greatest near the pressure side and suction side, and least near the leading edge and trailing edge. The strain distribution monitoring method can capture the location of maximum stress and the most severe fatigue damage on the blade, which are helpful for damage detection and load control, and further reduces O&M costs.
Batch channel normalized-CWGAN with Swin Transformer for imbalanced data fault diagnosis of rotating machinery
Authors: Fu Wenlong , Zheng Bo , Li Shuai , Liao Weiqing , Huang Yuguang , Chen Xiaoyue
Published: October 2024

In real scenarios, rotating machinery is mainly operated in optimal condition, leading to fault data scarce and difficult to collect. This issue results in imbalanced data, significantly limiting the effectiveness of intelligent fault diagnosis methods. To address this issue, a novel fault diagnosis method for rotating machinery is proposed in this paper, which combines the batch channel normalized conditional wasserstein generative adversarial network (BCN-CWGAN) with Swin Transformer. Firstly, the one-dimensional vibration signal is preprocessed into two-dimensional feature images using a symmetrized dot pattern. Subsequently, self-attention mechanism and deep feature learning module constructed by DenseNet are integrated into the generator of GAN to acquire more discriminative feature information. Meanwhile, the discriminator of GAN is combined with batch channel normalization strategy, which further enhances the generalization ability. Besides, a two time-scale update rule strategy enhances training stability and convergence speed by updating model parameters at different time scales. Then, the data augmentation capability of BCN-CWGAN is used to generate high-quality fault samples to augment the imbalanced dataset. Finally, Swin Transformer is combined to achieve accurate fault diagnosis. The performance enhancement of the proposed method is verified through comparison and diagnosis results of two engineering experiments, demonstrating its substantial value for research in engineering practice. With the proposed data augmentation method, the average accuracy of A
1, B
1, C
1, and D
1 datasets in experiment 1 reached 99.24%, 98.85%, 96.78%, and 96.04%, respectively. Meanwhile, the proposed method achieved the best accuracy in experiment 2.
On the role of the surface geometry in convex billiards
Authors: Dias Carneiro M J , Oliffson Kamphorst S , Pinto-de-Carvalho S , Vieira Morais C H
Published: October 2024

This work presents a framework for billiards in convex domains on two dimensional Riemannian manifolds. These domains are contained in connected, simply connected open subsets which are totally normal. In this context, some properties that have long been known for billiards on the plane are established. We prove the twist property of the billiard maps and establish some conditions for the existence and non-existence of rotational invariant curves. Although we prove that Lazutkin’s and Hubacher’s theorems are valid for general surfaces, we also find that Mather’s theorem does not apply to surfaces of non-negative curvature.
Inverted oscillator: quantum discrete spectrum
Authors: Chaabi Nadir , Bendjoudi Aymen , Maamache Mustapha
Published: October 2024

We use the invariant operator method to investigate the quantum characteristics of the inverted oscillator. We introduce a unitary transformation that maps a time-dependent general Hermitian linear invariant operator to a time-independent one, which describes a harmonic oscillator with a unit mass and a constant frequency. Our investigation includes three distinguished cases: negative frequency, zero frequency, and positive frequency. Our most interesting result concerns the last case. For the case of negative frequency, we propose a new inner product by the introduction of the new metric operator η. Coherent state for this case will be constructed.
Localization of elastic surface waves based on defect modes in non-Bragg structures
Authors: Zhang Qiao-Mu , Yang Lei , Fan Ya-Xian , Tao Zhi-Yong
Published: October 2024

The non-Bragg defect mode (NBDM) of elastic surface waves is experimentally investigated by inserting a defect in the middle of an antisymmetric periodic corrugated aluminum plate, which has been known as the non-Bragg structures since the observed band gaps are different from the traditional Bragg ones. Generally, the non-Bragg band gaps, existing away from the Bragg ones in a perfectly periodic waveguide, are created by the resonances of different transverse guided modes. The transmission spectra of elastic surface waves in antisymmetric structures with defects reveal the presence of defect modes within the non-Bragg gaps. Notably, the NBDM exhibits significant distribution characteristics in comparison to the traditional Bragg defect mode, including more complex elastic wave higher-order modes and localized wave energy near the defect. Consequently, the NBDM observed in the antisymmetric periodic waveguide with defects holds potential for utilization in other elastic wave functional devices, including filters and wave intensifiers.
All-optical simultaneous OR and AND optical logic gates based on nonlinear photonic crystal ring resonator
Authors: Gupta Priyanka Kumari , Paltani Punya Prasanna , Tripathi Shrivishal
Published: October 2024

An all-optical simultaneous OR and AND logic gates using the nonlinear Kerr effect and ring resonator based on a two-dimensional photonic crystal are proposed in this paper. The proposed structure has a resonant wavelength of 1551.3 nm and a power consumption (1 kW μm−2). The proposed structure is suitable for all-optical photonic integrations because of its simplicity and small size (23 μm × 30.4 μm). Moreover, the structure executes two logic operations without requiring an additional spare/control signal through a single structure, making fabrication easy. The total footprint of the photonic crystal ring resonator structure measures approximately 699 μm2. A very high contrast ratio of 26.10 dB and 25.34 dB is obtained for the OR and AND logic gates, with response times equal to 2 ps and 0.67 ps, respectively. In addition, the calculated bit rates for OR and AND logic gates are approximately 0.5 and 1.5 Tbps, respectively. The FullWAVE and BandSOLVE module of the Rsoft CAD commercial software is used for numerical and theoretical investigation of the structure.
MOF-derived ZnCo2O4 @ Ti3C2TX nanosheet with high microwave absorption
Authors: Zheng Boxiong , Liu Xingmin , Hua Yutuo
Published: October 2024

Electromagnetic wave absorbing (EWA) materials have a wide application in military technology, so it is necessary to develop EWA materials with lightweight, and wide absorption bandwidth and strong absorption. Novel two-dimensional material (MXene) with high dielectric constant property and unique structure has attracted extensive focus in microwave absorption. However, the high conductivity of MXene limits its application in microwave absorption. In this work, ZnCO2O4 nanoparticles were obtained via a hydrothermal method and subsequent heat treatment. Then it was anchored on MXene nanosheets. The effective absorption bandwidth (EAB) of the ZnCO2O4@Ti3C2Tx is 4.77GHz at 1.5mm thickness. Composites show great potential in the field of designing a new generation of efficient and lightweight microwave absorbers, which are expected to be used in various EWA applications.
Stearic Acid Modified Nano-ZnO Superhydrophobic Coating for Steel Mesh
Authors: Wang Yiru , Zhao Xin , Liu Yang , Hou Yangwu
Published: October 2024

To mitigate the detrimental effects of water on metal textiles, hydrophobic modification of such materials has garnered significant attention. However, traditional approaches often rely on complex procedures or costly materials, limiting their widespread application. Herein, we present a facile method for fabricating a superhydrophobic coating on steel mesh, and characterize the properties of the modified material. Initially, the surface of the dry steel mesh is uniformly coated with nano-ZnO crystals using a liquid deposition technique at room temperature. Subsequently, stearic acid is employed to hydrophobically modify the ZnO crystals, yielding a ZnO-based superhydrophobic coating. The influence of ZnO concentration and deposition duration on the surface crystal structure, hydrophobicity, and abrasion resistance is investigated. X-ray diffraction (XRD) analysis is performed to study the surface groups before and after hydrophobic modification, while static contact angle measurements are used to assess the hydrophobic properties of the coated surface. Remarkably, even after abrasion with 1000-mesh sandpaper, the superhydrophobic properties of the steel mesh with an optimized ZnO concentration decrease by only 4%. This simple, cost-effective, and highly efficient preparation method holds promising potential for applications in related fields.
Evaluation of two household decontamination methods on protective mask materials and disinfection effects
Authors: guozhuo Gong , qiuhua Wei , ji Liu , shubin Jin , ying Shi , yan Fang , xiaoyu Wang , yunyun Zhou , jianfeng Li , zhuowei Chen
Published: October 2024

In order to find affective disinfection methods for general public to reuse protective mask, which could address supply shortages in the period of epidemic, household ovens and household ultraviolet disinfection cabinets were used as decontamination tools, and the influence of decontamination process on the protective performance of masks including PFE and TIL, as well as virus (PV I and MHV) inactivation effect were completely evaluated. It was found that the dry heat and UVGI decontamination with household devices had a little impact on PFE or TIL of masks, which indicated that two process had little effect on mask material and face seal fit. The virus inactivation results showed that dry heat decontamination could effectively inactivate the virus on the masks, and UVGI decontamination could not completely inactivate the virus caused by the special shape of masks, which could be concluded that dry heat decontamination with household oven was a feasible method to reuse the mask, and UVGI decontamination was not recommended. This study had guiding significance for the decontamination and reuse of masks by the general public.
Study on the Effect of Al-10Sr Intermediate Alloy on the Modification of A356 Aluminum Alloy after Different Purification Treatments
Authors: Chen Gui-qing , Huang Shi-ta , Fu Gao-sheng , Wu Jian-xin , Chen Ruo-yu , Xie Zu-qiang
Published: October 2024

For three different purification treatment methods of aluminum melt: untreated (UT), conventional purification treatment (CPT), impurity removal flux purification treatment (IRF), and Al-10Sr intermediate alloy was applied for modification treatment. The results showed that due to the highest purity of aluminum liquid treated with IRF, the secondary dendrite spacing decreased by 31.32% after modification, and the eutectic silicon phase was in a granular and dispersed distribution. The tensile fracture exhibited ductile fracture characteristics, effectively improving the mechanical properties of the alloy. At the same time, it was found that reducing the Sr content did not decrease the modifying effect, indicating good purity of aluminum liquid can provide superior melt conditions for subsequent modification treatment.
Evaluation method of accelerated aging life of internal pressure seal layer of flexible composite hose
Authors: Shining Yuan , Guanglei Lv , Yujiang Sun , Xiaoling Zhang , jie Qu , Donghong Zhao , Haibin Gao , Lingqi Zeng
Published: October 2024

Aiming at the lack of evaluation methods for the life prediction of the inner pressure seal layer of in-service flexible composite hoses, the accelerated aging test method, which is the same as the transport medium and environmental conditions, and the Arrhenius equation principle are adopted to fit the life curve at different temperatures, so as to solve the problem that the life prediction of in-service flexible composite hoses is not possible at present. It provides the basis for the integrity management of flexible composite hose. The results show that the established aging life prediction model can meet the actual application requirements. The crosslinked polyethylene (XLPE) of internal pressure seal can be used for 76 years.
Study on Shell-Side Heat Transfer Enhancement Using Cinquefoil Orifice Mixed-Flow Baffle
Authors: Yu Lebin , Li Huifang , Wang Tong , Qian Caifu , Wu Zhiwei
Published: October 2024

For traditional heat exchangers, segmental baffles form a “dead zone” on the leeward side of the baffle, reducing heat transfer efficiency and causing significant pressure loss in the shell side. In response to these issues, this paper proposed a new type of baffle—the cinquefoil orifice mixed-flow baffle which introduces cinquefoil orifices on the segmental baffle. This design retains some cross-flow while also inducing longitudinal jet-flow as the fluid passes through the cinquefoil orifice. Numerical results found that the cinquefoil orifice baffle not only reduces the adverse effects of the “dead zone” but also enhances turbulence in the shell-side fluid flow due to the jet-induced entrainment effect, thereby improving heat transfer efficiency. With identical boundary conditions, the cinquefoil orifice mixed-flow baffle heat exchanger demonstrated superior shell-side heat transfer effectiveness compared to the traditional segmental baffle configuration. For the heat exchanger studied here, when the cinquefoil orifice is positioned closer to the baffle cut, the shell-side Nusselt number can increase by up to 18.8%, concurrently leading to a reduction of 4.62% in shell-side pressure drop. But it is also found that with increasing the number of cinquefoil orifices, the shell-side heat transfer efficiency did not increase monotonically, implying that in addition of the locations of the cinquefoil orifices, the proportion of the longitudinal jet-flow to the cross-flow could be optimized to get a best heat transfer efficiency.
The dynamic mechanism and optimal parameters of hydraulic jump induced disk floatation
Authors: Song Yuxiao , Huang Yuhong , Wang Hengtong , Du Ruhai
Published: October 2024

The hydraulic jump induced disk floatation is one of the important and complicated kinetic issues. Based on the observation of the hydraulic jump phenomenon and disk floatation in experiment, the gas-liquid two-phase flow and free surface advection are simulated by COMSOL Multiphysics. The force and flow fields, as well as the movement mode of the disk are analyzed through numerical simulation. Meanwhile, a theoretical model is firstly proposed to investigate the motion equations from the perspectives of energy and force. The stable, metastable and instable motion modes are found out and analyzed in detail by variable-controlled and comparison methods. The critical parameters of stability and instability of the disk are obtained by continuous interpolation method.
Simulation and analysis of fresnel diffraction with arbitrary shaped apertures
Authors: Xu Jianan , Wang Shoumin , Hu Yetong , Jin Yi
Published: October 2024

When studying diffraction and related issues, one often encounters the need to anticipate and estimate the diffraction patterns of variously shaped apertures. Optical experiments demand high environmental standards, and creating diffraction screens is cumbersome. Designing specialized optical experiments for such simple purposes is time-consuming and labor-intensive, and the clarity of the diffraction patterns is hard to guarantee. Therefore, obtaining diffraction patterns quickly and accurately in different situations has become a bottleneck. This article first obtains the integral expression of the Fresnel diffraction light field produced by a monochromatic point light source illuminating a diffraction hole based on Kirchhoff’s diffraction theory. Then, it establishes a mathematical model of the hole to obtain the integral element and uses mathematical software for computational simulation, obtaining diffraction patterns applicable to any shape hole. The paper performs calculations taking uppercase English letters as shaped aperture examples and conducts detailed analysis of their diffraction patterns.
Weak signal detection in chaotic noise background - based on VMD-EEMD and self-attention mechanisms
Authors: Zhao Shengli , Wu Yuanyuan , Jiang Xiuyue , Peng Deyang , Yu Jing
Published: October 2024

In this paper, a method for detection and estimation of weak harmonic signals in chaotic noise background is proposed. Firstly, the observed signal is smoothed by local weighted regression model to reduce the influence of noise. Then, the smoothed signals are decomposed into the intrinsic mode functions by Variational Mode Decomposition and Ensemble Empirical Mode Decomposition (VMD-EEMD). The components are reconstructed in the phase space, and the one-step prediction is carried out by adding a layer of the self-attention mechanism in the Long Short-Term Memory (LSTM). The one-step prediction error is obtained by summing up the prediction results of the components and the weak harmonic signals will be detected from the one-step prediction error. Finally, the periodogram method is used to detect whether the observed signals contain harmonic signals or not. If the observed signals contain harmonic signals, the amplitude and phase are estimated by the least squares method. Simulation experiments show that the method proposed in this paper has good performance. In detection of single harmonic signal, the Mean Absolute Error (MAE) and Mean Square Error (MSE) of the one-step prediction are 0.0212 and 0.00068 respectively; MAE and MSE of the signal estimation are 0.001977 and 0.0007 respectively. In detection of multiple harmonic signals, MAE and MSE of the one-step prediction are 0. 0248 and 0. 0006 respectively; MAE and MSE of the signal estimation are 0. 0035 and 1.681×10−5 respectively. The method proposed in this paper is able to efficiently detect weak harmonic signals from chaotic noise backgrounds and estimate the harmonic signals.
Calculation method of particle angular distribution based on directional probability approach in the Monte Carlo simulation
Authors: Liu Li , Zuo Yinghong , Niu Shengli , Zhu Jinhui , Shang Peng , Li Xiazhi
Published: October 2024

To address the limitations of narrow applicability and low computational efficiency in the existing methods for calculating particle angular distribution using Monte Carlo simulations, this paper proposes a method based on the directional probability approach. In this method, when calculating the fluence at a recording point using the directional probability approach, virtual particles are binned based on the cosine of the angle between their direction and different reference directions, enabling statistical calculation of the particle angular distribution at the recording point. The simulated one-dimensional angular distribution of particles at the recording point agrees well with the angular distribution at the recording surface, with a total fluence deviation of less than 2% and an angular distribution deviation of less than 5%. Additionally, to facilitate the coupling of particle transport simulation with other physical fields, corresponding methods have been established to statistically calculate the fluence components in different directions of the xyz coordinate system. This method can calculate one-dimensional, two-dimensional angular distributions, and different directional components of particles at any location within the radiation field, providing technical support for research in ray detection, radiation protection, nuclear radiation field analysis, and nuclear data evaluation.
Integrated Approach To Material Parameterization And Inflation Control Of Hyperelastic Membrane For Artificial Left Ventricle Development
Authors: Singh Aditya Kumar , Raj Deepak , Kumar Nirmal
Published: October 2024

In transitioning from conventional mechanical to biomedical applications, the choice of materials becomes critical. While hard materials like steel offer durability, their compatibility with biological systems, particularly blood, is limited due to the risk of cell damage. To address this, our research focuses on soft membrane-based systems to minimize haemolysis and optimize blood flow. By prioritizing biocompatibility and gentle interactions, our approach aims to enhance the safety and effectiveness of biomedical devices. Through innovative solutions in material selection and system design, we aim to advance cardiovascular medicine and contribute to the broader field of biomedical engineering.
The effect of scattering of phonons, size and grain boundary on electrical properties for (Co and Ni) nano metals
Authors: Almajedi Reza Fahad , Mohammed May A. S.
Published: October 2024

In this study of the electrical properties of metals (Nickel, Cobalt), we utilize the Fuchs-Sondheier model to analyse the surface scattering of electrons, commonly known as the surface scattering coefficient (p). Our findings reveal the impact of thickness on electrical resistivity for these metals. the Mayadas-Shatzkes model show speaks to all sorts of scattering that influence grain boundaries and known as grain boundary reflection coefficient (R), two of the foremost critical essential components that utilized in assessing measure impact agreeing to theoretical considers. influences electrical resistivity for Cobalt and Nickel. where the electrical characteristics of metal shift depending on the substance’s concentration (impurities, point defects and vacancies). The comes about at that point illustrated that the electrical resistivity at all temperatures increases with diminishing thickness, which shows that Cobalt and Nickel has surface scattering coefficient p(Co)=0.64, p(Ni)=0.543, Cobalt has R=0.0434 and Nickel R=0.011 as the grain boundary reflection coefficient.
Choosing the best locations to establish a nuclear power plant in Iraq with respect to radioactivity in those areas
Authors: Ahmed Emad H. , Karim Mahmood S. , Al-Ramahi Fouad K. Mashee
Published: October 2024

Iraq is in a good position to run its nuclear power plant to prepare for long-term energy needs, including electricity demands. The ideal location for the nuclear power plant was identified in this study, as were the standards for choosing that location. Salah al-Din and portions of Anbar were the options. This research takes into account seven criteria: low population density, residential area, river access, topography, and land use. The criteria are represented in GIS layers, a GIS analysis is conducted to provide many proposed sites, and the criteria are categorized based on the weight distance value. To protect the lives of the station employees, the natural radioactivity of the research region was also monitored. The effectiveness of the site suitability map lies in its capacity to evaluate and display the suitability rates for nuclear power plants. The nearest quarter for distance of water sources of the total samples, which is No. (15, 11, 19, 20 and 13), the water sources are (Tigris River, Haditha Dam, Tigris River, Tigris River, and Tharthar Lake). As for the distance from the city centers, the furthest quarter of the samples were chosen from the residential areas, which are each of the samples with No. (14, 13, 10, 6 and 12) respectively. To the city centers (Tikrit City, Tikrit City, Tikrit City, Rawa City, and Kubaisa City) respectively, with distances (51256, 50385, 38308, 30934, and 25392).