bluuebunny/crossref_metadata_2025 huggingface dataset:
A sustainable synthesis, characterization of modified waste onion peels and its exploration in various applications
Authors: Shweta  , Kaur Gurmeet
Published: July 2024

The modification of waste to a bio-based material that is economical, environmentally sustainable, and extremely effective is crucial for organic conversions. For bio waste, that doesn’t decompose easily and have bad impact on environment such as onion peels, a suitable method is introduced which focuses on utilizing onion peels, a commonly discarded agricultural waste, as a valuable resource for antibacterial studies and bio sensing of heavy metals. A comparative study to analyse these properties were done using onion peel extract and saponified onion peels. The saponified material was obtained by treating onion peels (Allium cepa) with sodium hydroxide in the presence of calcium carbonate. The popularity of saponification reaction and saponified material is rising because of their special qualities and uses as disinfectants, surfactants, antifungal agents, in drugs for target based delivery etc. The saponified onion peels was analyzed by FTIR (Fourier transform infrared spectroscopy), and XRD (X-ray diffraction), EDX (energy-dispersive X-ray), SEM (scanning electron microscopy). Furthermore, against Bacillus subtilis (Gram positive), antibacterial activity of onion extract and saponified onion peels were studied. In comparative study onion peel extract shows better inhibition zone then saponified onion peels. Bio sensing of heavy metals were done by using these materials, onion peel extract shows visual colour change with Nickel chloride (NiCl2), Cobalt chloride (CoCl2), Potassium bromide (KBr), Manganese sulphate (MnSO4), Mercury chloride (HgCl2) and Copper sulphate (CuSO4) metal salts.
Bio Materials, Biocompatibility & its Advancements in Medical
Authors: Salaam Ahmed , Thakur Sandeep , Prajapati Bhavin Kumar , Davala Karunakumar , Rajalakshmi B. , Nijhawan Ginni , Saha Amrita
Published: July 2024

There are different medical applications that utilize biomaterials to settle tissues, convey drugs, and make biomedical devices. This paper gives a relevant analysis of biomaterials talking about their groupings, highlights, biocompatibility issues, and a variety of medical uses or applications. The paper separates biomaterials into polymers, ceramics, metals, and composites explaining them in detail with a focus on particular traits that suit indicated medical purposes. According to the paper, Polymers are adaptable materials that can be utilized as scaffolds for tissue engineering, artificial blood vessels, or drug carriers in aqueous media. On talking about ceramics in this paper, ceramics are commonly utilized in bone replacement material due to their extraordinary mechanical properties and bioactivity. Basically, all ceramics such as tricalcium phosphate or hydroxyapatite have had higher success rates because of their high mineral substance making them perfect materials for dental implants. Metals like titanium, cobalt-chromium alloys, or stainless steel have found wide utilization since they have great mechanical strength and erosion resistance which is frequently required for end osseous dental implants. As a result, biocompatibility is given priority in biomaterial design, with the requirement for materials to connect safely and agreeably with natural frameworks. In reality, improvements in biomaterial innovation have empowered the advancement of innovative materials to boost their biocompatibility through such strategies as surface adjustments and bio-mimetic coatings. These all advancements have a high growth in this sector and become useful for the medical industry. Moreover, this paper clarifies how these biomaterials play an impactful portion in the mechanical advancement of medical devices which incorporates catheters, implantable devices, drug conveyance systems, and orthopaedic implants among others. The major utilization of artificial polymers is found in making medical instruments whereas ceramics are broadly utilized in orthopaedics and dentistry which upgrades bone recovery and Osseo integration. Similarly, metals that are well known for their mechanical ability, as well as biocompatibility, have a substantial existence in orthopaedic implants alongside cardiovascular devices. Through a wide range review of biomaterials and their numerous uses in healthcare, this paper can contribute a few valuable insights concerning how this will shape the future of medical technology and persistent care.
Finite Element Analysis of 3D Printed Block Prepared of Sustainable Acrylonitrile Butadiene Styrene (ABS)
Authors: Sonia Pankaj , K Aravinda , Hayder Nibras , Venkatcharyulu S. , Lakhanpal Sorabh , Singh Harjeet , Limbadri K.
Published: July 2024

ABS and chain-branched amylopectin exhibit poor processing capabilities, making them unsuitable for 3D printing utilizations. While ABS exhibits excellent mechanical properties with high processing costs, it lacks the practical requirements of PLA, an environment-friendly polymer with poor mechanical performances. Studying the toxicity of 3-D printer emissions and the causes of toxicity both in vivo and in vitro is necessary in light of the rapidly expanding applications of 3-D printing technological advances, the documented emissions, and the possible adverse reactions from exposed to those emissions. Despite these limitations, ABS and PLA continue to be developed for 3D printing applications. Several mechanical behaviors, including tensile strength, creep, and fatigue, are examined in the study to determine the structural integrity and durability of a 3D-printed ABS square block. The results of the safety factor analysis show a minimum value of 0.1823, indicating the presence of potential failure points and the need for design optimization. The material can last long under dynamic loads, as shown by the fatigue study. This study not only improves ABS parts in real-life uses but also helps grasp their strength better. It gives clues for their future design and making. Using experimental and simulation data, the study optimizes 3D printing parameters and improves ABS materials’ structural efficiency by integrating finite element methods with practical manufacturing outcomes.
A Comprehensive Analysis of Column Optimization for Circular Elevated Water Tanks in Seismic Environments
Authors: Chandrashekar Rakesh , Nagpal Amandeep , Samatha Anthappagudem , Praveen  , Sabah Abed AL-Zahra Jabbar Ahmed , Singh Shivani , Reddy M. Sreenivasa
Published: July 2024

Water storage is critical everywhere, especially in places where there is a severe water shortage. Understanding its vital significance, water storage projects are receiving more attention in an effort to guarantee regular availability to this resource that is necessary for daily existence. The study explores the complex dynamics of raised water tanks and describes the structural details of slabs, beams, columns, and footings. These element channel loads carefully to the soil sub-grade, allowing their complex interaction. The study focuses into many load types, including seismic, living, and dead, and as a result, the analytical framework reveals the dynamic behaviours of the water tank. The main aim of this research project is to perform a thorough hydrological investigation of circular water tanks. Furthermore, the study presents the findings from a thorough analysis of round raised water tanks, with a focus on column optimisation. The research examines different column arrangement with capabilities that remain constant across the range, from 10 to 14 columns. In the context of Zone II seismic conditions, the study preserves relative integrity by keeping heights and diameters constant. By conducting a detailed analysis of crucial structural considerations, such as maximum bending moment, maximum displacement, and base shear, the study aims to clarify the subtle performance characteristics present in circular elevated water tanks under seismic loading scenarios.
Quelques réflexions autour des liens entre océan, arts et sciences. À propos d’un colloque au Muséum national d’histoire naturelle
Authors: Artaud Hélène
Published: July 2024

Le 12 janvier 2023, à l’amphithéâtre de la grande galerie de l’Évolution (MNHN), un colloque a réuni une quinzaine de chercheurs, scientifiques et artistes autour d’une thématique qui mobilise de plus en plus l’attention du public et s’inscrit dans le champ particulièrement vivace ces dernières décennies des relations entre arts et écologie. Portant sur le rôle imparti aux arts dans les enjeux océaniques contemporains, cette journée entendait répondre à deux questions principales : la première consistait à questionner la pertinence de maintenir des séparations disciplinaires héritées des Modernes dans un monde soumis à l’effondrement et se demandait si la place de plus en plus importante conférée à l’art dans les débats écologiques n’était pas l’indice que les limites de ce grand partage avaient été atteintes. La seconde question portait sur l’originalité de l’objet océanique pour penser et se saisir de ces mondes abîmés.
Updates on altered signaling pathways in tumor drug resistance
Authors: Li Xiuzhi , Huang Xin , Chang Ming , Lin Risheng , Zhang Jian , Lu Yi
Published: July 2024

Curing cancer has always presented a formidable clinical challenge. Among the various treatment strategies for combating tumors, the combination of targeted therapy and immunotherapy has recently assumed significant importance. Regrettably, while targeted drugs demonstrate efficiency in the early stages of cancer treatment, patients inevitably develop drug resistance as treatment progresses, ultimately resulting in treatment failure and death. Currently, effective countermeasures against drug-resistant tumor cells remain limited, and research into the mechanisms of drug resistance continues to garner profound interest. The current understanding of drug resistance primarily focuses on two aspects: intrinsic or primary drug resistance, and acquired or secondary drug resistance. Further explanations delve into molecular mechanisms, including acquired gene mutations, epigenetic modifications, the plasticity of cancer stem cells, and the mediation of exosomes. With the advancement of single-cell analysis, our understanding of these potential mechanisms has become more comprehensive. In this review, we initially explore classical signaling pathways related to tumorigenesis and cancer cell progression. Additionally, we summarize recent findings regarding gene mutations and modifications related to drug resistance in cancer. Finally, we discuss the plasticity of cancer stem cells and the latest research on exosome-mediated tumor drug resistance.
One-Pot, Two-Step Synthesis of Highly Functionalized 4-Indolyl/Pyrrolyl-Chromanes via a para-Quinone Methide Formation–1,8-Addition Sequence
Authors: Sridharan Vellaisamy , Khatoon Rafia , Jandial Tanvi , Gupta Anish , Kundan Sujata
Published: July 2024

An efficient one-pot, two-step synthesis of structurally diverse 4-indolyl-/pyrrolyl-chromanes was developed starting from o-propargylated salicylaldehydes, 2,6-dialkylphenols and indoles/pyrrole. This process begins with a sequential secondary amine-catalyzed formation of p-quinone methides followed by Brønsted acid catalyzed 1,8-addition with indoles/pyrrole to access the functionalized chromanes in high yields (up to 91%). This sequential reaction generates three new C–C bonds, shows high step- and atom-economy with only one molecule of water as the side product and gives access to complex molecular frameworks without the need for the isolation of the intermediates.
Functional Restoration of Bilateral Wrist Level Hand Amputee with Six-Toe Transfers and Three Free Flaps: An Alternative to Hand Allotransplantation or Prosthesis
Authors: Nehete Rajendra , Nehete Anita , Ghalme Amol , Kulkarni Abhishek , Fidvi Al Iqyan
Published: July 2024

Introduction Hand amputation at the wrist level is severely disabling, especially when bilateral. It is paramount to restore the hand function to the best possible level for the patient's daily living activities, as well as optimal social and occupational rehabilitation. There are various options for restoration of function after amputation at wrist and distal forearm levels including Krukenberg's operation, variations of toe transfers, hand allotransplantation, and prosthesis. Krukenberg's procedure and the reconstruction using toe transfer like Vilkki's procedure or two-toe transfers, restore only the pinch. Hand allotransplantation, although it gives excellent function, has limitations due to the complications of immunosuppression. Functional hand prosthesis, though superior in cosmetic appearance, have again limitations in function, and the cost is prohibitive for most patients in our country.

Materials and Methods We present the unique case of a bilateral hand amputation at the wrist level reconstructed with three toes and free anterolateral thigh (ALT) flap in a single-stage surgery for each hand. In two stages, the patient had six toes transferred to both hands.

Result All transferred toes and all three free (two ALT and one thoracodorsal artery perforator) flaps survived completely. Three-finger grip (tripod pinch) was thus restored in each hand. The hook grip was also restored well by the reconstructed two fingers. Within 3 months after surgery, the patient could perform all activities of daily living. He resumed his original job with some modification of his work within 6 months postinjury.

Conclusion Hand reconstruction using three toes and a free flap is an excellent option for functional restoration for amputation at the wrist and distal forearm level. It allows an early return to function and good social and professional integration of the patient. This procedure is a potential alternative to expensive prosthesis and allotransplantation for a bilateral hand amputation.
Computed Tomography Scan Correlation of Position of Appendix with Present Literature
Authors: Kachare Manohar , Patil Abhijit D. , Gamanagatti Shanta A. , Kulkarni Sanjay B.
Published: July 2024

Background The appendix exhibits varied anatomical orientations, which significantly influence the diagnosis and treatment of appendicitis. Existing literature predominantly relies on cadaveric studies to delineate common appendix positions, lacking comprehensive computed tomography (CT)-based investigations on a large scale. Thus, our study endeavors to delineate the prevailing position of the appendix on CT scans and ascertain its concordance with existing literature, thereby augmenting our understanding of this anatomical entity. This cross-sectional study was conducted in a tertiary care hospital setting.

Materials and Methods A total of 1,068 patients aged 18 years and older, undergoing abdominal CT scans at the hospital between July 2020 and July 2021, were enrolled in the study, with exclusion criteria applied to conditions that could distort anatomical features. The position of the appendix was meticulously documented for each patient, alongside measurements including diameter, wall thickness, and origin. Data collection utilized a predefined Microsoft Excel sheet. Subsequently, numerical and relative frequencies were computed for appendiceal positions and origins. Additionally, diameter and wall thickness were assessed, and pertinent parameters were derived.

Results The relative frequencies of various potential appendiceal positions observed in our study were as follows: subcecal: 6.6%; paracecal: 1.2%; pelvic: 21.9%; postileal: 32.9%; preileal: 6.7%; retrocecal: 28.5%; subhepatic: 2.2%.

Conclusion In contrast to traditional assumptions, our findings reveal that the most prevalent positions of the appendix are postileal, retrocecal, and pelvic, challenging historical beliefs.
Exploring Sleep Patterns in 3,475 College Students: A Comparative Study of Geographical Location, Gender, and Age
Authors: Moussa-Chamari Imen , Romdhani Mohamed , Farooq Abdulaziz , Trabelsi Khaled , Yousfi Narimen , Kamoun Karim , Ahmadian Arezou , Almarri Senaid Salem , Chamari Karim , Hue Olivier
Published: July 2024

Objective Sleep is a fundamental physiological process essential for maintaining overall health and optimal functioning across various cognitive, emotional, and physical domains. To cross-sectionally investigate the sleep pattern among college students according to geographical location, gender, and age.

Materials and Methods A total of 3,475 valid responses, 3,366 from 4 continents (Africa – n = 1,095; America – n = 182; Asia – n = 1,562; Europe – n = 527); 2,075 from female students and 1,369 from male students (n = 3,444), were analyzed. Sleep quality, insomnia, and daytime sleepiness were assessed using validated questionnaires (Pittsburgh Sleep Quality Index [PSQI], Insomnia Severity Index [ISI], and Epworth Sleepiness Scale [ESS], respectively).

Results Students from all continents had poor sleep quality, and there were inter-countries differences in sleep quality. The frequency of poor sleep quality and subclinical-to-clinical insomnia were higher among Asian (AsiS) and African students (AfS) compared with American (AmS) and European students (EuS) (p < 0.05). Asian students had a greater frequency of excessive daytime sleepiness (EDS) compared with those from other continents (p < 0.05). Females showed higher mean ISI scores (p < 0.001) as well as a greater frequency of poor sleep quality (p < 0.05), subclinical-to-clinical insomnia (p < 0.05), and EDS (p < 0.05) compared with males. Insufficient sleep duration was more frequent in older-aged groups (i.e., 26–30, 31–35, and > 36 years) compared with the ≤ 20 years age group (p < 0.05). Excessive daytime sleepiness was more frequent in younger age groups (i.e., ≤ 20 and 21–25 years) versus the > 36 years (p < 0.05) group. There were no significant differences in the frequency of various degrees of insomnia across age groups.

Conclusion Our results suggest the need for tailored interventions for addressing sleep disturbances among college students of all age groups, with a specific focus on AsiS and AfS, as well as female students.
Clinicohematological Profile of Patients with Bicytopenia
Authors: Murshed Najib Muaamer Faed , Bhat Shubha P.
Published: July 2024

Background Bicytopenia (BC) is a reduction in counts in any of two cell lineages of blood, which can be a combination of anemia with thrombocytopenia, anemia with leukopenia, or leukopenia with thrombocytopenia. The etiology of BC can be a malignancy, nonmalignant disease, infectious cause, or drug-induced.

Aim To assess the clinicohematological profile in patients with BC.

Materials and Methods This prospective study was conducted in the hematology laboratory at the Justice K.S. Hegde Charitable Hospital. Patients with BC detected during the analysis of blood for any clinical condition were included in the study. Blood parameters assessed were hemoglobin, red blood cell count, total leukocyte count, and platelet count.

Results In this study, 86 patients' samples with BC were collected, out of which 55.8% were male, and 44.2% were female. The most common BC was anemia with thrombocytopenia (69.8%). The most common etiology of BC was found to be nonmalignant (37.2%), followed by malignant (37.2%), infectious (25.6%), and drug-induced (4.7%) cases. Most of the patients with BC presented with fever, pallor, and generalized weakness.

Conclusion Anemia with thrombocytopenia emerged as the predominant form of BC in the nonmalignant group, while the malignant etiology group presented with anemia with leukopenia. The infectious etiology group presented with leukopenia with thrombocytopenia. Neonatal sepsis emerged as the most prevalent cause of BC in the age group younger than 10 years, viral fever in the age group of 10 to 39 years, acute lymphoblastic leukemia in the age group of older than 70 years, and chronic liver disease in patients aged between 40 and 69 years.
Enhancing organizational sustainable innovation performance through organizational readiness for big data analytics
Authors: Arshad Muhammad , Qadir Aneela , Ahmad Waqar , Rafique Muhammad
Published: July 2024

Organizations must employ big data analytics to maintain sustained innovation in the highly dynamic and evolving business landscape. Even though BDA has a transformative power to revolutionize how businesses do things and engage with their customers’ adopting BDA has faced significant challenges, especially in developing countries. This research aims to create a theoretical framework to understand how organizational readiness for BDA can influence sustainable innovation performance. Sampling errors were mitigated through a time-lagged study design, and the data was collected in three phases. The test results using Partial Least Squares Structural Equation Modeling show that organizational readiness is a critical mediator, establishing a robust chain between BDA skills and sustainable innovation performance. The results of this study imply the need for organizational foundation and alignment, which are critical to the compelling strategic deployment of BDA for sustainability innovation performance. Thus, this study can offer a valuable contribution to this topic in the future and a profound implication of the phenomenon at receptive stages.
Enhancing the description of multi-time-scale geophysical phenomena: Incorporating finite time Scale separation and feedback, illustrated with the case of a 1D variable of interest
Authors: Bianucci M. , Mannella R.
Published: July 2024

Stochastic approaches play a vital role in weather, climate, and, more in general, geophysics systems, addressing processes and scales beyond the resolution of deterministic models. Similar to equilibrium/non-equilibrium thermodynamics, intricate fast and local dynamics may not always be the primary focus. Practical applications often prioritize observables capturing phenomena at dominant temporal and spatial scales. Developing models for these “large-scale” observables, resulting from averaging fast and local contributions, can be simplified into Low Order Models (LOMs) with reduced degrees of freedom described by ordinary differential equations. Unresolved degrees of freedom are introduced as stochastic components, exhibiting either Markovian or non-Markovian characteristics. The challenge lies in deriving dependable stochastic differential equations representing the statistics of real large-scale, slow features in the climate/ocean system. While paralleling material physics, it is crucial to recognize that direct transfer of tools and outcomes is hindered by the non-Hamiltonian nature of climate/geophysical LOMs and the impracticality of a Markovian treatment of noise due to wide-ranging time scales. A critical examination of the conventional statistical mechanics approach, customized for such LOMs, becomes essential. To this end, we propose utilizing an approach based on the operator cumulant method, which has been recently revisited and generalized, along with the linear response method in a non-Hamiltonian setting. Formal results are then derived, and applications to some typical classes of examples are presented to clarify this approach.
A two-dimensional calibration for resolving nano-positioner pedestal micro-deformation crosstalk
Authors: Chen Guangzheng , Fan Kai , Niu Runda , Zhu Shuyu , Xu Tao , Feng Zhihua
Published: July 2024

This paper proposes a two-dimensional calibration method for resolving the nano-positioner pedestal micro-deformation crosstalk errors during the auction process. This refinement aims to enhance the nano-positioner’s accuracy and reduce coupling crosstalk errors. The reaction force exerted by the piezoelectric actuator can cause micro-deformation in the nano-positioner sensor pedestal, causing substantial errors in uncalibrated closed-loop control. This phenomenon has been previously overlooked. According to the two-degree of freedom parallel-symmetric decoupled nano-positioner deformation characteristics, a two-dimensional calibration matrix is proposed to suppress the crosstalk between two axes caused by the micro-deformation of the sensor pedestal. Experimental results show that the calibrated closed-loop system reduces X-axis and Y-axis coupling crosstalk errors to 1/67th and 1/18th of the uncalibrated closed-loop system, respectively, concurrently enhancing the positioning accuracy to 11.8 and 17 times that of the uncalibrated closed-loop system. The calibrated closed-loop feedback control method proposed in this paper proves effective for all compact nano-positioners with pedestal deformation issues. This research provides a crucial reference for the design of nano-positioners, offering insights into enhancing their accuracy and mitigating crosstalk issues.
Investigation on fixed pitch Darrieus vertical axis wind turbine
Authors: Kavade Ramesh K. , Sonekar Mahesh M. , Choudhari Dilip S. , Malwe Prateek D. , Sherje Nitin P. , Ansari Mushtaq Ahmad , Shah Mohd Asif , Abdul Zahra Musaddak Maher , Kumar Abhinav
Published: July 2024

Small-scale Darrieus wind turbines have a wide scope in areas that are isolated from the power grid for such small-scale household applications. Applications of wind turbines on house roofs are one potential way to generate electricity from wind energy harvesting in low-wind urban locations. This work studies the aerodynamic behavior of a vertical axis wind turbine based on a MATLAB programming mathematical model. The NACA0021 airfoil profile blade was used in this present research investigation. The turbine was fabricated with dimensions such as chord length, c = 95 mm, blade height, h = 600 mm, and turbine diameter, D = 600 mm. The experimental results of the turbine for air velocity from 1 to 12 ms−1 were used in this paper and compared with analytical results. It has been observed that the fixed-pitch turbine does not start by itself at a low air velocity of 1 to 5 m/s due to a minimum and negative torque.
Dispersion mismatch correction for evident chromatic anomaly in low coherence interferometry
Authors: Iyer Rishyashring R. , Yang Lingxiao , Sorrells Janet E. , Chaney Eric J. , Spillman Darold R. , Boppart Stephen A.
Published: July 2024

The applications of ultrafast optics to biomedical microscopy have expanded rapidly in recent years, including interferometric techniques like optical coherence tomography and microscopy (OCT/OCM). The advances of ultra-high resolution OCT and the inclusion of OCT/OCM in multimodal systems combined with multiphoton microscopy have marked a transition from using pseudo-continuous broadband sources, such as superluminescent diodes, to ultrafast supercontinuum optical sources. We report anomalies in the dispersion profiles of low-coherence ultrafast pulses through long and non-identical arms of a Michelson interferometer that are well beyond group delay or third-order dispersions. This chromatic anomaly worsens the observed axial resolution and causes fringe artifacts in the reconstructed tomograms in OCT/OCM using traditional algorithms. We present DISpersion COmpensation Techniques for Evident Chromatic Anomalies (DISCOTECA) as a universal solution to address the problem of chromatic dispersion mismatch in interferometry, especially with ultrafast sources. First, we demonstrate the origin of these artifacts through the self-phase modulation of ultrafast pulses due to focusing elements in the beam path. Next, we present three solution paradigms for DISCOTECA: optical, optoelectronic, and computational, along with quantitative comparisons to traditional methods to highlight the improvements to the dynamic range and axial profile. We explain the piecewise reconstruction of the phase mismatch between the arms of the spectral-domain interferometer using a modified short-term Fourier transform algorithm inspired by spectroscopic OCT. Finally, we present a decision-making guide for evaluating the utility of DISCOTECA in interferometry and for the artifact-free reconstruction of OCT images using an ultrafast supercontinuum source for biomedical applications.
Research on nonequilibrium plasma-assisted evaporation and ignition of n-decane droplet
Authors: Zhou Siyin , Zheng Zhi , Nie Wansheng
Published: July 2024

To evaluate the nanosecond pulsed discharge plasma-assisted evaporation and ignition attributes of hydrocarbon fuel droplets, numerical models are established. The influences of nonequilibrium plasma on the characteristics of n-decane droplet evaporation and ignition are numerically studied through a loosely coupled method employing a one-dimensional (1D) fully transient model of droplet evaporation and ignition and a model of nanosecond pulse plasma discharge. The results show that the reaction rate of the initial phase of n-decane droplet ignition is increased by nonequilibrium plasma. In addition, both the evaporation and ignition of the droplet are accelerated. Increasing the reduced electric field of the discharge leads to decreases in the droplet ignition delay time, survival time, and shortening amplitude. The evaporative cooling effect, which occurs at the initial phase of droplet ignition and typically decreases the local temperature surrounding a droplet surface, is weakened by the plasma. As the reduced electric field increases, the time to generate a high-temperature zone (>1800 K) decreases, while its duration increases. The initial phase of n-decane droplet ignition, in which the flame temperature increases while the flame radius decreases, is strongly affected by the plasma during the initial ignition phase. However, the plasma has little impact on the peak flame temperature and the flame radius during the stable combustion phase of the droplet. According to reaction kinetics analysis, the plasma directly interferes with the elementary reactions R330 (nC10H22 + O = 3-C10H21 + OH) and R331 (nC10H22 + O = 2-C10H21 + OH) of n-decane/air combustion. Moreover, the dissociation and oxidation processes of intermediate products are accelerated. Then, the important reaction rates, which determine the ignition delay time, increase indirectly. Thus, the overall ignition delay time of the n-decane droplet is shortened.
Investigation on vibration characteristics induced by gas–liquid two-phase flows in a horizontal pipe
Authors: Zhao Nan-Nan , Feng Jian-Jun , Guo Peng-Cheng , Zhu Guo-Jun , Li Chen-Hao , Luo Xing-Qi
Published: July 2024

The intrinsic characteristics of multiphase flow inevitably result in vibrations within the pipe structure. The evolution of vibration characteristics is crucial for monitoring the stability of the multiphase flow pipelines. However, under high liquid velocity condition, the influence of flow pattern on the gas–liquid two-phase flow-induced vibration (GTFIV) of the pipe remains unclear. In this paper, the vibration signals in the horizontal pipe under different flow patterns at high liquid velocity are measured by a vibration test system. Synchronously, images inside the pipe are captured to illustrate the flow mechanism. The results show that the α stable distribution model holds higher fitting accuracy than the standard normal distribution for the GTFIV. The random behavior of small-scale bubbles determines the structural richness of the GTFIV. The multifractal characteristics of the GTFIV are strongly dependent on the flow pattern. The formation of the gas plug leads to significant unevenness in the fractal structure of the GTFIV. The multifractal strength of the GTFIV gradually increases as the flow pattern transforms from dispersed bubble flow to slug flow. Some multifractal spectrum parameters of the vibration signal can be applied for the identification of flow patterns in the pipe.
Rogue curves in the Davey–Stewartson I equation
Authors: Yang Bo , Yang Jianke
Published: July 2024

We report new rogue wave patterns whose wave crests form closed or open curves in the spatial plane, which we call rogue curves, in the Davey–Stewartson I equation. These rogue curves come in various striking shapes, such as rings, double rings, and many others. They emerge from a uniform background (possibly with a few lumps on it), reach high amplitude in such striking shapes, and then disappear into the same background again. We reveal that these rogue curves would arise when an internal parameter in bilinear expressions of the rogue waves is real and large. Analytically, we show that these rogue curves are predicted by root curves of certain types of double-real-variable polynomials. We compare analytical predictions of rogue curves to true solutions and demonstrate good agreement between them.
Synaptic plasticity in zinc oxide-based flexible invisible transparent memristor by modulating oxygen concentration
Authors: Patnaik Asutosh , Acharya Arpan , Tiwari Kabin , Saha Priyanka , Sahoo Narayan , Panda Debashis
Published: July 2024

Artificial synapses based on memristors are used in emulating the synaptic plasticity behavior of a human brain. Here, we have proposed a transparent memristor based on aluminum zinc oxide (AZO) on a flexible substrate—polyethylene naphthalate. We have analyzed the elemental composition of the gadget subjected to the optimized flow rate of Ar/O2 = 2/1 by x-ray photoelectron spectroscopy. The prepared AZO/ZnO/indium-doped tin oxide memristor exhibits a bipolar switching behavior with Vset/Vreset of 1.4/−2.0 V. The results reflect an acceptable endurance of >500 cycles and retention of 104 s. The optimized device shows an improvement in the non-linearity of potentiation—2.31/depression—3.05 and has more than 25 cycles of stability. The transparency is checked using a UV-visible spectrophotometer showing 90% transparency in the visible region making the device suitable for applications in invisible electronics. Our results reflect that the proposed device can be used as a transparent electrode in making artificial synapses for neuromorphic applications.
Analysis of coherent structures over interacting barchan dunes based on tomographic particle image velocimetry
Authors: Han Xiaolei , Rinoshika Hiroka , Zhou Yuyang , Li Jiawei , Rinoshika Akira
Published: July 2024

The influence of barchan dune interaction upon unsteady flow separation and wake dynamics around the fixed-bed downstream barchan dune (DBD) model are experimentally investigated at a Reynolds number of 2640 based on the tomographic particle image velocimetry (PIV) system. The time-averaged statistics including the mean velocities, recirculation area, vortex spatial topology, Reynolds stress, and turbulent kinetic energy were used to characterize the flow field and large-scale anisotropy. It was found that arch-shaped vortex “chains” with strong spanwise coherence shedding from isolated barchan crestline populate the whole wake region, while elongated rod-shaped vortex structures with strong streamwise coherence induced by the up-downwash flow around the DBD were found to fill the whole measurement range, which is closely related to “sheltering” effect on the incoming flow acting at DBD due to the presence of upstream barchan dune (UBD). Additionally, in order to study the complex dynamic features of these predominated vortex structure transformations, time-resolved planar particle image velocimetry was applied. This technique allows for providing complementary insights into the temporal behavior of the unsteady coherent flow structures populating the wake field in different experimental configurations. It was found that the basic unsteady flapping motion, vortex roll-up, and complex vortex interactions including vortex pairing, merging, and breaking up can all be analyzed by dividing into certain scales with ease in a combination wavelet and Lagrangian framework.
Investigation of the bubble deflection using graphics processing unit accelerated multiple relaxation time lattice Boltzmann method: The effect of bubble size and liquid viscosity
Authors: Liu Yujin , Zheng Longyun , Xia Yannan , Guo Kai , Liu Hui , Liu Chunjiang
Published: July 2024

Bubble deflection is important for bubble motion and bubble mass transfer in multiphase reactors. However, the mechanism triggering the instability is controversial. In this study, we first perform a graphics processing unit-accelerated multiple relaxation time lattice Boltzmann method (MRT-LBM) to simulate the motion process of single bubbles (1.8–8.0 mm) freely rising in stationary liquids with different viscosities. Then, we further analyze the influence of the bubble size and liquid viscosity on the characteristics of the time-dependent bubble motion, including the bubble shape, velocity, and deflection, based on the high-precision numerical simulation results. The results show that the formation and shedding of bubble wake vortices are responsible for the oscillation of the bubble shape. The interaction of bubble wake vortices and bubble shape is the primary cause of bubble deflection. Finally, an empirical model, taking into account the bubble acceleration and deflection angle, is developed to characterize the effect of bubble size and liquid viscosity on the drag coefficient of a rising bubble. This study provides insight into the bubble deflection and the bubble dynamics.
Influence of mass conservation cavitation boundary on transient performance of water-lubricated bearings
Authors: Li Xingyang , Zhang Guokun , Li Deao , Li Qiang , Xu Weiwei , Hao Muming
Published: July 2024

Given the current research gap regarding cavitation phenomena and startup conditions in water-lubricated bearings (WLBs), this study offers an innovative approach by integrating the mass conservation boundary condition proposed by Jakobsson, Floberg, and Olsson (known as the JFO boundary condition) with a transient mixed lubrication model of WLBs. It also considers the impact of elastic deformation and surface roughness peaks, thus establishing a transient startup model of WLBs that incorporates the cavitation effect. Furthermore, the dynamic behaviors of this boundary condition are contrasted with the commonly used Reynolds boundary condition during the startup process of the bearings, as well as under eccentric and step load impacts. The findings demonstrate that the JFO boundary condition, accounting for cavitation effects, significantly influences the transient performance of WLBs. The presence of a cavitation region diminishes the damping of the bearing system following step load impacts, leading to increased overshoot and adjustment time while weakening the system's self-adjusting ability against step loads. This study offers valuable insights for theoretical analysis of ship propulsion systems operating under complex conditions.
Successive rebounds of obliquely impinging water droplets on nanostructured superhydrophobic surfaces
Authors: Jia Youquan , Zhang Zhiming , Wang Yile , Lin Shiji , Jin Yakang , Chen Longquan
Published: July 2024

The impact and rebound of water droplets on superhydrophobic surfaces frequently happen in nature and also in a number of industrial processes, which has thus stimulated strenuous efforts to explore the underlying hydrodynamics. Despite that massive achievements have been made over the past decades, existing works are mostly focusing on the short-time bouncing dynamics after a single impact; however, the long-term, successive droplet rebounds, which are practically more important, only received very limited attention. In this work, we perform an experimental investigation on the impact of water droplets on inclined nanostructured superhydrophobic surfaces at low Weber numbers, where massive complete rebounds arise. It was found that an obliquely impinging droplet would undergo many impacts on the superhydrophobic surface, accompanying with sliding on the surface, jumping in air, and complex shape evolutions. Based on the kinematic analyses, we demonstrate that the droplet motion on the surface can be decomposed into a perpendicular impact, which is dominated by the capillary and inertial forces, and a translational motion under the drive of gravity. By contrast, the jumping motion after droplet rebound is solely governed by the gravitational force, yet relevant droplet characteristics are affected by the energy loss during the impact on superhydrophobic surface, which sets the maximum height that the droplet rebounds to. In addition, three distinct shape evolution modes–namely, oscillation, rotation and their combination–were identified on jumping droplets, and the direction of a rotational droplet can be altered via the following impingement on the superhydrophobic surface.
Laser pulse induced second- and third-harmonic generation of gold nanorods with real-time time-dependent density functional tight binding (RT-TDDFTB) method
Authors: Giri Sajal Kumar , Schatz George C.
Published: July 2024

In this study, we investigate second- and third-harmonic generation processes in Au nanorod systems using the real-time time-dependent density functional tight binding method. Our study focuses on the computation of nonlinear signals based on the time dependent dipole response induced by linearly polarized laser pulses interacting with nanoparticles. We systematically explore the influence of various laser parameters, including pump intensity, duration, frequency, and polarization directions, on harmonic generation. We demonstrate all the results using Au nanorod dimer systems arranged in end-to-end configurations, and disrupting the spatial symmetry of regular single nanorod systems is crucial for second-harmonic generation processes. Furthermore, we study the impact of nanorod lengths, which lead to variable plasmon energies, on harmonic generation, and estimates of polarizabilities and hyper-polarizabilities are provided.
Electron scattering cross sectional data for precursors used in plasma-assisted deposition
Authors: Pandey Meenu , Antony Bobby
Published: July 2024

In this study, a comprehensive electron scattering analysis is performed on the precursors AlF3 and AlCl3 used in the plasma-assisted deposition technique. We used the R-matrix and spherical complex optical potential formalisms to calculate the integral elastic cross sections for electron energies between 0.1 and 5000 eV. At low energies, we computed differential and integral elastic cross sections and excitation cross sections using the R-matrix method. We have also reported the ionization cross section using the complex scattering potential-ionization contribution method and the binary-encounter-Bethe method. Our computed results show overall good agreement with the available data in the literature.
Experimental investigation of interactions between a water droplet and an airflow boundary layer
Authors: Shi Z. Y. , Wu Z. L. , Tan H. J. , Liu Y.
Published: July 2024

The deformation and movement of droplets is widely relevant in many fields of research. The present work experimentally investigates the evolution of a single droplet interacting with an air boundary layer. A series of experiments are carried out using a high-speed photography technique to determine the effects of the airflow velocity, drop height, and droplet size. The morphological characteristics can be classified into three types according to the experiments. The outcomes indicate that both the drop height and the airflow velocity significantly influence the maximum streamwise spreading length, but only the drop height has an impact on the maximum lateral spreading width. The maximum streamwise spreading factor follows a power function relationship with WeRe−0.5. In addition, the crater maximum streamwise and lateral spreading diameters are mainly influenced by the drop height. An energy conversion model is established by considering the effects of the aerodynamic drag force, surface tension, and viscous force. This study provides experimental reference data for the scenario of a droplet interacting with an air boundary layer.
Semiconductor lasers for photonic neuromorphic computing and photonic spiking neural networks: A perspective
Authors: Xiang Shuiying , Han Yanan , Gao Shuang , Song Ziwei , Zhang Yahui , Zheng Dianzhuang , Yu Chengyang , Guo Xingxing , Zeng XinTao , Huang Zhiquan , Hao Yue
Published: July 2024

Photonic neuromorphic computing has emerged as a promising avenue toward building a high-speed, low-latency, and energy-efficient non-von-Neumann computing system. Photonic spiking neural network (PSNN) exploits brain-like spatiotemporal processing to realize high-performance neuromorphic computing. Linear weighting and nonlinear spiking activation are two fundamental functions of a SNN. However, the nonlinear computation of PSNN remains a significant challenge. Therefore, this perspective focuses on the nonlinear computation of photonic spiking neurons, including numerical simulation, device fabrication, and experimental demonstration. Different photonic spiking neurons are considered, such as vertical-cavity surface-emitting lasers, distributed feedback (DFB) lasers, Fabry–Pérot (FP) lasers, or semiconductor lasers embedded with saturable absorbers (SAs) (e.g., FP-SA and DFB-SA). PSNN architectures, including fully connected and convolutional structures, are developed, and supervised and unsupervised learning algorithms that take into account optical constraints are introduced to accomplish specific applications. This work covers devices, architectures, learning algorithms, and applications for photonic and optoelectronic neuromorphic computing and provides our perspective on the challenges and prospects of photonic neuromorphic computing based on semiconductor lasers.
Helium metastable density determination in the COST reference source by absolutely calibrated optical emission spectroscopy
Authors: Myers Brayden , Fiebrandt Marcel , Stapelmann Katharina
Published: July 2024

Helium metastable densities in the COST Reference Microplasma Jet are estimated for a variety of He/N2 admixtures and dissipated powers by applying a collisional-radiative model to absolutely calibrated optical emission spectroscopy measurements. This is accomplished by delineating the excitation mechanisms that result in the N2(C–B) and N2+(B–X) emission bands, the latter of which is strongly coupled to the presence of helium metastables. A number of other plasma parameters are established and discussed for each operating condition including the electron energy distribution function, reduced electric field, rate constants, and electron density. With these parameters, the reaction rates for the primary ionization pathways are also calculated, emphasizing the importance of helium metastables for discharge sustainment. Good agreement with the existing literature is found for most plasma parameters and for helium metastable densities, in particular. A clear [N2]−1 relationship between the nitrogen concentration and density of helium metastables is demonstrated, as has been identified in previous studies in analogous atmospheric pressure plasma jets. This validates the efficacy of this optical technique for determining helium metastable densities and establishes it as a viable, and in many cases, more accessible alternative to other means of quantifying helium metastables in low-temperature plasmas.