bluuebunny/crossref_metadata_2025 huggingface dataset:
IoT-Based Assistant for Alzheimer's Patient with Reminder System and Tracking Using GPS
Authors: Reena R. , R Srishti , M Harini , Mohamed Aezeden , Surayyo Ergasheva , R Senthil Kumar
Published: July 2023

In many nations, there is serious worry over the rising incidence of Alzheimer's disease (AD). New approaches are therefore needed for preventing, identifying, and helping people with AD. Alzheimer patients are facing difficulties during day-to-day activities in terms of traveling and receiving accurate information from their surroundings. We have proposed a smart belt that overcomes most of the problems of Alzheimer’s patients. The belt genuinely aids in identifying the challenges encountered in daily life. The smart belt is embedded with Arduino UNO and a global positioning system (GPS) that helps in sensing emergency alerts. The proposed smart belt provides continuous information about the location of Alzheimer’s patients to the concerned caretaker at an interval of five minutes. The pulse heart rate sensor installed on the belt monitors the health of the user. This heart rate sensor is used to detect the heart rate, and when the heart rate increases a buzzer makes an alert sound and sends an immediate message to the caretaker about the increased heart rate and location. It also contains a speaker module that tells the phone number and address of the caretaker and also some important help line emergency numbers. Sensors are used for achieving these functions. It supports them in remembering their family member’s numbers. This smart belt is useful for patients with mild and moderate Alzheimer's disease
Smart Poultry House Monitoring System Using IoT
Authors: Sasirekha R. , R Kaviya , G Saranya , Mohamed Aezeden , Iroda Utaeva
Published: July 2023

In modern India, the poultry industry is one of the largest and fastest growing segments of the agrarian economy. Due to standardized farming management and excellent manufacturing practices, chicken output has been steadily increasing in recent years. Automation is crucial in the modern world, and the Internet of Things (IoT) concept is also evolving rapidly. It is possible to automate manual processes using acertain technique. The project's objective is to use IoT technologies to automate management-related chores on a chicken farm. Environmental factors like temperature and humidity are just a few that have an impact on chicken wellness. By keeping an eye on the chicks according to their cycle, the proprietor is informed. The weight of the chicken is taken into consideration for high - quality manufacturing. If all these factors remain consistent, chicken production and quality increase.
Detection of Breast Cancer Using Infrared Thermal Images for Improved Accuracy by Using Random Forest and Multilayer Perceptron
Authors: M Thejeshwar , S Stella Jenifer Isbella
Published: July 2023

At the present time, breast cancer is one of the most often diagnosed forms of cancer in females. Mammography is the most common form of screening imaging used to identify breast cancer in its earlier stages. Nevertheless, thermal infrared pictures (thermography) can be utilized to detect lesions in dense breasts. In this study, the typical areas reflect warmer temperatures than malignant areas. In this study, we offer a unique approach for modeling the temperature variations in normal and abnormal breasts by combining the Random forest and Multilayer perceptron techniques. The project aims to study the accuracy, sensitivity, and specificity of the infrared breast cancer images using infrared thermal images using random forest and multilayer perceptron algorithms and comparing the accuracy, specificity, and sensitivity. Materials and Methods: The information for this study was s gained from thermal images from Visual labs DMR-IR. The samples were considered as (N=60) for Random Forest and (N= 60) for MultiLayer Perceptron. Novel Matlab software is used to calculate accuracy, specificity, and sensitivity. Results: The result demonstrates the accuracy of the thermal breast images using SPSS software. A statistically insignificant difference exists, with Random Forest accuracy (92.5%) with specificity (90%) and with sensitivity (95%) and demonstrated a better outcome in comparison with Multilayer Perceptron accuracy (90%), specificity (91.6%) and sensitivity (88.3%). Conclusion: Random Forest gives better accuracy, specificity, and sensitivity than Multilayer Perceptron to detect breast cancer.
Emergency order response strategy under supply chain collaboration
Authors: Tan Hao , Fu Xiao
Published: July 2023

This paper studies the production and ordering response strategy with uncertain demand in two-tier supply chain composed of a social planner and a manufacturer. In light of the uncertain market demand, the manufacturer needs advance production before receiving the regular order from social planner to make quick response, and reserve some additional production capacity in case of emergency orders. We derive the conditions whereby the manufacturer can benefit from the emergency production and emergency orders and the social planner is willing to place the emergency orders and upgrade the optimal decisions with Pareto improvement. Besides, we find that, (1) the unit cost for emergency order is either too high or low, which might be worse off if the emergency order opportunity is provided to social planner; (2) even if the centralized case is better than the decentralized case in terms of the total cost, the social planner prefers decentralized case to centralized case. Finally, we use the real data to prove the theoretical analysis and show that the emergency supply mechanism can almost meet domestic demand. At the same time, we determine the optimal unit cost for emergency order based on total cost and respective costs for both parties.
Comparison of Exercise Capacity, Physical Activity Level and
Peripheral Muscle Strength in Systemic Lupus Erythematosus Patients with Healthy
Individuals
Authors: Sari Fulden , Bayram Selin , Oskay Deran , Tufan Abdurrahman
Published: July 2023

Background This study investigated physical activity, peripheral muscle
strength, exercise capacity, sleep, fatigue, anxiety and depression in patients
with systemic lupus erythematosus (SLE).

Material and Methods Twenty-six patients with SLE, median age 32.5
(25–43) years, and 29 healthy individuals, median age 30 (23–32)
years, were included. Exercise capacity (6-minute walk test (6MWT)), peripheral
muscle strength (dynamometer), physical activity (Mi Band 4 smart band), fatigue
(Fatigue Severity Scale (FSS)), anxiety and depression (Hospital Anxiety
Depression scale (HAD)), quality of life (SLE-specific QOL scale (SLEQoL)) and
sleep (Pittsburgh Sleep Quality Index (PSQI)) were assessed.

Results Demographic characteristics were similar in both groups. 6MWT
distance, peripheral muscle strength, physical activity level, SLEQoL and PSQI
scores were significantly lower, while FSS and HAD scores were higher in
patients with SLE (p<0.05). Moreover, pre-test and post-test heart
rates, dyspnea and fatigue severity scores were higher in patients with SLE than
in healthy individuals (p<0.05).

Conclusion Patients with SLE had lower exercise capacity, muscle strength,
physical activity, quality of life and sleep quality, along with more common
fatigue, anxiety and depression. Strategies need to be developed to improve
these symptoms in patients with SLE for a favourable outcome.
Renal Oxygen Saturations and Acute Kidney Injury in the Preterm Infant with Patent Ductus Arteriosus
Authors: Rose Laura A. , Frymoyer Adam , Bhombal Shazia , Chock Valerie Y.
Published: July 2023

Objective Decreased near-infrared spectroscopy (NIRS) measures of renal oxygen saturation (Rsat) have identified preterm infants with a hemodynamically significant patent ductus arteriosus (hsPDA). NIRS may further identify infants at risk for acute kidney injury (AKI) in a population with concern for hsPDA.

Study Design Review of infants ≤29 weeks' gestation undergoing NIRS and echocardiography due to concern for hsPDA. The hsPDA was defined by two of the following: moderate-large size, left to right shunt, aortic flow reversal, left atrial enlargement. AKI was defined by neonatal modified Kidney Disease Improving Global Outcomes (KDIGO). Rsat and cerebral saturation (Csat), averaged over 1 hour, were evaluated for the 24-hour period around echocardiography.

Results Among 77 infants, 29 (38%) had AKI by neonatal modified KDIGO criteria. hsPDA was found on echocardiography in 59 (77%). There were no differences in hsPDA in infants with and without AKI (p = 0.1). Rsat was not associated with AKI (p = 0.3). Infants on dopamine had less Rsat variability (p < 0.01).

Conclusion Rsat prior to echocardiography did not discriminate AKI in this cohort of preterm infants at risk for hsPDA; however, data may not capture optimal timing of Rsat measurement before AKI.

Key Points
Respiratory and Musculoskeletal Long-Term Outcomes after Surgical Resection of Congenital Cystic Adenomatoid Malformation of the Lung in Newborns, Infants, and Toddlers
Authors: Busti Matteo , Zarfati Angelo , Valfre Laura , Conforti Andrea , Bagolan Pietro
Published: July 2023

Introduction The long-term outcomes of children who underwent surgery for congenital cystic adenomatoid malformation of the lung (CCAML) are not well documented, particularly regarding orthopaedic and respiratory follow-up (FU). The aim of this study was to assess the long-term pulmonary and orthopaedic outcomes of surgically treated CCAML in newborns, infants, and toddlers.

Materials and Methods Retrospective examination of prospectively recorded data of consecutive patients with CCAML who underwent surgery at our tertiary referral institution from January 2000 to December 2015 (newborns, infants, and toddlers). Clinical, radiological, and surgical data, as well as FU data were revised. A multidisciplinary team followed the patients after discharge at scheduled time points.

Results Seventy-seven patients were included. After surgery, patients were followed for a median of 8 years (range: 1–19 years) until they reached a median age of 8 years (range: 2–19 years). Thirty patients (39%) developed wheezing and 21 (27%) had lower respiratory tract infections (LRTIs) within 4 years of age. However, more than 50% of patients with respiratory symptoms underwent complete remission in the following 4 years. Thirty-one patients (40%) developed at least one minimal musculoskeletal deformity. Eighteen (23%) had scoliosis, 17 (22%) thoracic asymmetry, 10 (12%) pectus excavatum, and 5 (6%) winged scapula.

Conclusions Patients operated for CCAML had good overall outcomes despite pulmonary symptoms and musculoskeletal sequelae. Even though these issues are frequently paucisymptomatic, trying to use less-invasive procedures (such as minimally axillary open “muscle-sparing” thoracotomy or thoracoscopy) may reduce this burden. A structured multidisciplinary FU is required.
Anterior Cruciate Ligament Return to Play: Where Are We Now?
Authors: Oladeji Lasun , Reynolds Grace , Gonzales Hyeri , DeFroda Steven
Published: July 2023

Anterior cruciate ligament reconstruction (ACLR) is a commonly performed orthopaedic procedure, and it is crucial to assess an athlete's readiness to safely return to sports following ACLR to minimize the risk of reinjury. Despite this, determining optimal return to play (RTP) criteria following ACLR that is accurate, accessible, and reproducible remains challenging. This review aims to discuss commonly employed RTP criteria domains, including functional assessments, patient-reported outcomes, and psychological tests, as well as emerging technologies such as magnetic resonance imaging (MRI) that may play a role as a gold standard in RTP assessment. The findings of this review suggest RTP decision making after ACL surgery is nuanced and traditionally used objective measures do not perfectly predict RTS rates or clinical outcomes. In the future, a standardized MRI screening tool could help predict reinjury. The role of functional and psychological patient-reported outcome measures needs to defined, and objective criteria should be rigorously evaluated for whether they accurately screen an athlete's physical readiness and should be expanded to include more sport-specific movement analysis.
Endoscopic Assessment of Colorectal Polyps
Authors: Pettis Jaron , Paruch Jennifer
Published: July 2023

Colorectal cancer is the third most common cancer among men and the second among women. In the United States alone, there are 150,000 cases diagnosed each year. Colonoscopy remains the best method for identifying, evaluating, and intervening on patients with precancerous lesions. Multiple guidelines and techniques are available to assist the endoscopist with accurate diagnosis of these lesions. These include the Paris, Narrow-Band Imaging (NBI) International Colorectal Endoscopic (NICE), Japan NBI Expert Team (JNET), Kudo, Hiroshima, and Shudo classifications which utilize techniques such as chromoendoscopy, narrow-band imaging, and endocytoscopy to evaluate pit pattern and surface morphology. Utilization of these tools can help the endoscopist predict the cytology of a colonic lesion and select the most appropriate method for resection while maximizing organ preservation.
Endoscopic Colorectal Stenting: Lessons Learned from a Two-Decade Journey
Authors: Oner Muharrem , Abbas Maher A.
Published: July 2023

Endoscopic colorectal stenting has gained momentum over the last two decades as a viable alternative to surgical intervention in a subgroup of patients with colorectal disease. Stenting can be used as a temporizing bridge to surgical intervention or as a definitive treatment measure. Patient selection and the technical expertise of the endoscopist are of paramount importance to optimize the clinical outcome. Technical skills in therapeutic endoscopy and the choice of proper equipment including the consumables are required for the conduct of a safe and successful procedure. In this article, we share the lessons learned from a two-decade journey of the senior author with therapeutic endoscopy.
Robotic-Assisted Nipple Sparing Mastectomy
Authors: Burns Heather R. , McCarter Jacob H. , King Brody W. , Yu Jessie Z. , Hwang Rosa F.
Published: July 2023

Minimally invasive approaches to breast surgery have evolved from endoscopic techniques to recent developments in robotic-assisted mastectomies. Initial studies on robotic-assisted nipple-sparing mastectomy (RNSM) have shown improved patient satisfaction and aesthetic outcomes with similar complication rates and oncological outcomes in selected patients. This chapter reviews techniques used and available data on complications and clinical outcomes for RNSM. Currently, RNSM is an investigational technique in the United States and should be performed in clinical trials with U.S. Food & Drug Administration approval to rigorously evaluate the safety and effectiveness of this approach.
Do emotions conquer facts? A CCME model for the impact of emotional information on implicit attitudes in the post-truth era
Authors: Yang Ya , Xiu Lichao , Chen Xuejiao , Yu Guoming
Published: July 2023

This study aimed to examine the influence of emotional media information on information-processing mechanisms in the current post-truth era. A cognitive conflict monitoring and evaluation (CCME) model was proposed to explore news audiences’ attention and implicit attitudes. The study had a 2 (information type, emotional vs. neutral) × 2 (condition, compatible vs. incompatible) × 3 (electrode position: Fz vs. Cz vs. Pz) design, and an implicit association test (IAT) was administered, with event-related potential (ERP) data collected. The results revealed that emotional information evoked different information-processing mechanisms than neutral information. First, in the early conflict-monitoring stage, emotional information altered arousal, and more attentional resources were allocated to semantic processing. Second, in the late evaluation stage, the lack of attentional resources (due to prior allocation) reduced the late-stage evaluation of the target stimuli by participants. Thus, in this post-truth era, attentional resources may be exhausted by processing emotional information in unnecessary media cues irrelevant to facts, inducing early cognitive conflict and prolonged late-stage evaluation of news articles.
Beyond 5G: Enabling ultrafast data transfer with microcomb technology
Authors: Lim Alane
Published: July 2023

Researchers demonstrate proof-of-concept with higher carrier frequency than current 5G wireless standards.
Sniffing out a better electronic nose
Authors: Patrick Chris
Published: July 2023

Recent research on metal halide perovskites points to their promise as sensors for gases and volatile organic compounds in food, healthcare, and other industries.
A numerical study on the thermal behavior of high pressure hydrogen in the on-board storage cylinder
Authors: Li Ji-Qiang , Li Ji-Chao , Wang Xiang-Yang , Xu Heng , Kwon Jeong-Tae , Leng ChengLin
Published: July 2023

The fast refueling of compressed hydrogen has an important influence on the efficiency and safety of the filling process. Precision measurements of the thermodynamic characteristics of hydrogen under the filling process are becoming more important as hydrogen energy is developed and used. One of the key elements of hydrogen fuel cell vehicles is the on-board hydrogen storage cylinder (HSC). Due to the compression of the hydrogen during filling, there could be a fast increase in temperature. The tank's maximum temperature and maximum fueling pressure are both restricted to less than 358.15 K and 125% of the tank's design pressure for safety reasons. This study revealed the hydrogen temperature rise during refueling and developed a theoretical model for computing the temperature rise in the HSC during the high-pressure refueling procedure. The HSC filling procedure was examined using a theoretical approach. Also, the relationship between the refueling procedure and the temperature change of hydrogen in the type IV tank was investigated. The temperature evolution mechanism of various HSCs was explained, and predictions were made for the minimum precooling temperature needed for hydrogen under various filling scenarios. The results of the theoretical analysis gave a theoretical foundation to the present method for controlling the hydrogen temperature of the gas source in the hydrogenation station, which then enables us to determine the optimum amount of energy needed for cooling hydrogen in the hydrogen refueling station.
High power laser heating of nuclear ceramics for the generation of controlled spatiotemporal gradients
Authors: Reymond Matthieu , Doualle Thomas , Sercombe Jerome , Rocca Mathilde , Nasselahsen Mehdi , Colin Christian , Pontillon Yves , Gallais Laurent
Published: July 2023

The use of high-power lasers to reach the high temperatures typical for off-normal conditions in nuclear reactor fuel or to determine its properties at high temperature is a relevant and proven technique in the nuclear research community. Conducting studies at high temperature with full control in space and time of the thermal gradients is, however, a challenge. In this paper, we present a combination of methodologies, experiments, and models to drive nuclear fuel samples in thermal conditions relevant to the study of nuclear fuel materials. Based on the use of high-power (kW) lasers with beam shaping and temporal laser control, our experimental approach allows one to heat depleted UO2 samples and obtain precise control of the temporal gradients, in the ms range, and spatial gradients, in the 100 μm range. The coupling with numerical simulations allows one to determine the temperature distribution in the depth of the sample and to develop a thermo-mechanical interpretation of the results. We will present the methodology allowing one to properly compare experimental and simulation results by taking into account the optical response of the instrumentation, the laser–UO2 interaction, and the resulting heat source term. We will show that we can express the heat source term resulting from the laser loading either by an analytical description or statistically based on Monte-Carlo simulation. A fairly good agreement between the recorded temperature and the simulation results is shown. The presented methodology can be extended to other materials with a proper choice of laser wavelength and instrumentation based on the optical properties of the investigated material.
Improving machine learning force fields for molecular dynamics simulations with fine-grained force metrics
Authors: Wang Zun , Wu Hongfei , Sun Lixin , He Xinheng , Liu Zhirong , Shao Bin , Wang Tong , Liu Tie-Yan
Published: July 2023

Machine learning force fields (MLFFs) have gained popularity in recent years as they provide a cost-effective alternative to ab initio molecular dynamics (MD) simulations. Despite a small error on the test set, MLFFs inherently suffer from generalization and robustness issues during MD simulations. To alleviate these issues, we propose global force metrics and fine-grained metrics from element and conformation aspects to systematically measure MLFFs for every atom and every conformation of molecules. We selected three state-of-the-art MLFFs (ET, NequIP, and ViSNet) and comprehensively evaluated on aspirin, Ac-Ala3-NHMe, and Chignolin MD datasets with the number of atoms ranging from 21 to 166. Driven by the trained MLFFs on these molecules, we performed MD simulations from different initial conformations, analyzed the relationship between the force metrics and the stability of simulation trajectories, and investigated the reason for collapsed simulations. Finally, the performance of MLFFs and the stability of MD simulations can be further improved guided by the proposed force metrics for model training, specifically training MLFF models with these force metrics as loss functions, fine-tuning by reweighting samples in the original dataset, and continued training by recruiting additional unexplored data.
A laser-based Ångstrom method for in-plane thermal characterization of isotropic and anisotropic materials using infrared imaging
Authors: Gaitonde Aalok U. , Candadai Aaditya A. , Weibel Justin A. , Marconnet Amy M.
Published: July 2023

High heat fluxes generated in electronics and semiconductor packages require materials with high thermal conductivity to effectively diffuse the heat and avoid local hotspots. Engineered heat spreading materials typically exhibit anisotropic conduction behavior due to their composite construction. The design of thermal management solutions is often limited by the lack of fast and accurate characterization techniques for such anisotropic materials. A popular technique for measuring the thermal diffusivity of bulk materials is the Ångstrom method, where a thin strip or rod of material is heated periodically at one end, and the corresponding transient temperature profile is used to infer the thermal diffusivity. However, this method is generally limited to the characterization of one-dimensional samples and requires multiple measurements with multiple samples to characterize anisotropic materials. Here, we present a new measurement technique for characterizing the isotropic and anisotropic in-plane thermal properties of thin films and sheets as an extension of the one-dimensional Ångstrom method and other lock-in thermography techniques. The measurement leverages non-contact infrared temperature mapping to measure the thermal response from laser-based periodic heating at the center of a suspended thin film sample. Uniquely, our novel data extraction method does not require precise knowledge of the boundary conditions. To validate the accuracy of this technique, numerical models are developed to generate transient temperature profiles for hypothetical anisotropic materials with known properties. The resultant temperature profiles are processed through our fitting algorithm to extract the in-plane thermal conductivities without knowledge of the input properties of the model. Across a wide range of in-plane thermal conductivities, these results agree well with the input values. Experiments demonstrate the approach for a known isotropic reference material and an anisotropic heat spreading material. The limits of accuracy of this technique are identified based on the experimental and sample parameters. Further standardization of this measurement technique will enable the development and characterization of engineered heat spreading materials with desired anisotropic properties for various applications.
Performance scaling with an applied magnetic field in indirect-drive inertial confinement fusion implosions
Authors: Sio H. , Moody J. D. , Pollock B. B. , Strozzi D. J. , Ho D. D.-M. , Walsh C. A. , Kemp G. E. , Lahmann B. , Kucheyev S. O. , Kozioziemski B. , Carroll E. G. , Kroll J. , Yanagisawa D. K. , Angus J. , Bachmann B. , Baker A. A. , Bayu Aji L. B. , Bhandarkar S. D. , Bude J. D. , Divol L. , Engwall A. M. , Ferguson B. , Fry J. , Hagler L. , Hartouni E. , Herrmann M. C. , Hsing W. , Holunga D. M. , Javedani J. , Johnson A. , Khan S. , Kalantar D. , Kohut T. , Logan B. G. , Masters N. , Nikroo A. , Izumi N. , Orsi N. , Piston K. , Provencher C. , Rowe A. , Sater J. , Shin S. J. , Skulina K. , Stygar W. A. , Tang V. , Winters S. E. , Zimmerman G. , Chittenden J. P. , Appelbe B. , Boxall A. , Crilly A. , O'Neill S. , Barnak D. , Davies J. , Peebles J. , Bae J. H. , Clark K. , Havre M. , Mauldin M. , Ratledge M. , Vonhof S. , Adrian P. , Reichelt B. , Fujioka S. , Fraenkel M.
Published: July 2023

Magnetizing a cryogenic deuterium–tritium (DT)-layered inertial confinement fusion (ICF) implosion can improve performance by reducing thermal conduction and improving DT-alpha confinement in the hot spot. A room-temperature, magnetized indirect-drive ICF platform at the National Ignition Facility has been developed, using a high-Z, high-resistivity AuTa4 alloy as the hohlraum wall material. Experiments show a 2.5× increase in deuterium–deuterium (DD) neutron yield and a 0.8-keV increase in hot-spot temperature with the application of a 12-T B-field. For an initial 26-T B-field, we observed a 2.9× yield increase and a 1.1-keV temperature increase, with the inferred burn-averaged B-field in the compressed hot spot estimated to be 7.1 ± 1.8 kT using measured primary DD-n and secondary DT-n neutron yields.
Significant sensitivity enhancement of single crystal CdSe x-ray detector by liquid nitrogen cooling
Authors: Song Yanan , Wang Shimao , Zhao Xiao , Hu Qianqian , Huang Changbao , Meng Gang , Gnatyuk Volodymyr , Ni Youbao , Wu Haixin
Published: July 2023

Owing to the large x-ray attenuation coefficient, appropriate bandgap, high resistivity, and high mobility-lifetime (μτ) product, binary II–VI semiconductor CdSe is a promising x-ray detection material and it has exhibited excellent x-ray detection at room temperature (RT). For further improving the characteristics of CdSe x-ray detectors, the electrical properties of CdSe single crystals (SCs) grown through the pressure-assisted vertical Bridgman method and their x-ray detection performance have been investigated at RT and liquid nitrogen temperature (LNT), respectively. The significantly enhanced x-ray photocurrent and the prolonged response time of the devices operating at LNT indicate the photogenerated carrier lifetime could be increased by the enhanced trapping–detrapping effect obviously, and the μτ product of CdSe SCs increases from 1.39 × 10−5 to 5.34 × 10−4 cm2 V−1 with temperature lowering from RT to LNT. Meanwhile, an ultrahigh sensitivity of 5.24 × 106μC Gyair−1 cm−2 and an extremely low detection limit of 3.68 nGyair s−1 have been acquired by the CdSe SC based x-ray detectors at LNT, which is 140 times higher and 5.8 times lower than it has been at RT. Compared with conventional semiconductor x-ray detectors, the ultra-high sensitivity and extremely low detection limit of CdSe SC based detectors make their application prospects very promising.
Epidemic spreading on multi-layer networks with active nodes
Authors: Zhang Hu , Cao Lingling , Fu Chuanji , Cai Shimin , Gao Yachun
Published: July 2023

Investigations on spreading dynamics based on complex networks have received widespread attention these years due to the COVID-19 epidemic, which are conducive to corresponding prevention policies. As for the COVID-19 epidemic itself, the latent time and mobile crowds are two important and inescapable factors that contribute to the significant prevalence. Focusing on these two factors, this paper systematically investigates the epidemic spreading in multiple spaces with mobile crowds. Specifically, we propose a SEIS (Susceptible-Exposed-Infected-Susceptible) model that considers the latent time based on a multi-layer network with active nodes which indicate the mobile crowds. The steady-state equations and epidemic threshold of the SEIS model are deduced and discussed. And by comprehensively discussing the key model parameters, we find that (1) due to the latent time, there is a “cumulative effect” on the infected, leading to the “peaks” or “shoulders” of the curves of the infected individuals, and the system can switch among three states with the relative parameter combinations changing; (2) the minimal mobile crowds can also cause the significant prevalence of the epidemic at the steady state, which is suggested by the zero-point phase change in the proportional curves of infected individuals. These results can provide a theoretical basis for formulating epidemic prevention policies.
Active control approach to temporal acoustic cloaking
Authors: Lasri Or , Sirota Lea
Published: July 2023

We propose a realization of a transformation-based acoustic temporal cloak using an active closed-loop control approach to an equivalent electromagnetic problem. Unlike the more common spatial cloaks, the goal of which is hiding fixed objects from detection, the goal of the temporal cloak is hiding the occurrence of events during a finite period of time. In electromagnetic systems, in which events represent, for example, leakage of signals from transmission lines or optical fibers, temporal cloaking solutions usually rely on nonlinear phenomena related to the fibers properties or on modulating the properties of the propagation medium itself. In particular, the transformation-based solution requires modulating the constitutive parameters of the medium in both space and time. In acoustic systems, an event may represent an object crossing a propagation channel and temporarily blocking it. Our control approach is fully linear, where the required change in the medium parameters is programmed into the controllers and created by external actuators in real-time. This cloaking system keeps the physical medium unchanged and enables re-programing of the cloaking parameters upon request. We demonstrate our solution in a simulation of a one-dimensional water channel.
Investigation on auto-ignition and chemical energy release characteristics of pilot hydrogen in supersonic combustion flow
Authors: Shi Wen , Tian Ye , Jiang Anlin , Le Jialing , Zhong Fuyu
Published: July 2023

This study investigates auto-ignition and heat release characteristics of pilot hydrogen chemical energy in a scramjet combustor equipped with a single cavity. Experiments are conducted in a direct-connected facility simulating Mach 6.0 flight conditions with a total temperature of 1350 K and total pressure of 1.75 MPa. Data are obtained from schlieren imaging, hydroxyl planar laser-induced fluorescence, flame emission, and 10-kHz static pressure transducers. The present investigation extends the pilot hydrogen ignition delay experimental dataset and clarifies the instabilities present in the ignition process. The results show that the supersonic internal flow of a confined cavity exhibits self-oscillating behavior with a dominant frequency of approximately 141.3 Hz. The primary chemical reaction occurs at mid-cavity, where the chemical energy of the pilot hydrogen begins to be converted into heat energy, then approaches the cavity ramp before finally being distributed across the whole cavity. The combustion mode is the cavity-stabilized scramjet mode. The distribution of hydroxyl radicals varies significantly because the combustion in the cavity is unsteady. The ignition delay time increases as the injection pressure rises. However, an injection pressure of 4.0 MPa produces an ignition delay of 24.7 ms, which is apparently shorter than the delay under an injection pressure of 3.5 MPa and similar to that under an injection pressure of 3.0 MPa. The injection of pilot hydrogen under high pressures induces greater heat release and more intense blockage effects, thus enhancing the probability of successful ignition and stable combustion.
Wave resistance of a ship moving in a lead between rigid ice sheets of finite thickness
Authors: Zhang Zhihang , Maki Kevin
Published: July 2023

This paper presents a combined theoretical and numerical analysis of a ship traveling in open water between rigid ice sheets of finite thickness with the objective to understand how the modeled ice influences the wave resistance and ship wave pattern. The first part of the analysis uses a mathematical model to evaluate the wave resistance in deep-water channels (or an ice sheet that reaches the sea floor). The model is able to separate the contributions of the transverse and divergent waves to the total wave resistance. Significant influence of both the ship speed and channel width is observed to both increase and decrease the wave resistance relative to the open water condition by as much as 50%. The second part of the analysis uses high-resolution computational fluid dynamics (CFD) on a contemporary ship that is traveling between two rigid ice sheets with finite thickness. The CFD simulations identify the critical ice thickness that corresponds to the condition in which the ice sheets function nearly as channel walls. It is found that the effect on the wave resistance is noticeable when the ice is 5% of the fundamental wavelength, and when the ice sheets are thicker than 20% of the fundamental wavelength, the resistance change due to the plates is nearly that of channel walls.
Exploding foils with artificial structure as a source of ultraviolet radiation
Authors: Tilikin I. N. , Shelkovenko T. A. , Pikuz S. A. , Oginov A. V. , Mingaleev A. R. , Romanova V. M. , Ter-Oganesyan A. E.
Published: July 2023

The results of the study of radiation produced by the electrical explosion of Al foil with a thickness of 4 μm with an artificial periodic structure of periodic holes with 50–400 μm steps created by laser engraving are presented. The experiments were carried out on a KING pulse high-current generator (220 kA, 40 kV, 300 ns). Images of exploded foils were recorded using pinhole cameras with a 20 μm aperture on a four-frame microchannel plate camera with 5 ns temporal resolution. In experiments on the electrical explosion of thin foils, it was shown that the application of an artificial periodic structure to the foil leads to a much more uniform radiation in the UV spectrum range along the entire length and width of the foil. Uniform radiation was observed from 20 to 70 ns. It is shown that such radiation can be used for the imaging of test objects or plasma objects like exploded wires.
Out-of-plane spin-to-charge conversion at low temperatures in graphene/MoTe2 heterostructures
Authors: Ontoso Nerea , Safeer C. K. , Ingla-Aynés Josep , Herling Franz , Hueso Luis E. , Calvo M. Reyes , Casanova Fèlix
Published: July 2023

Multi-directional spin-to-charge conversion—in which spin polarizations with different orientations can be converted into a charge current in the same direction—has been demonstrated in low-symmetry materials and interfaces. This is possible because, in these systems, spin-to-charge conversion can occur in unconventional configurations in which charge current, spin current, and polarization do not need to be mutually orthogonal. Here, we explore, in the low temperature regime, the spin-to-charge conversion in heterostructures of graphene with the low-symmetry 1T' phase of MoTe2. First, we observe the emergence of charge conversion for out-of-plane spins at temperatures below 100 K. This unconventional component is allowed by the symmetries of both MoTe2 and graphene and likely arises from spin Hall effect in the spin–orbit proximitized graphene. Moreover, we examine the low-temperature evolution of non-local voltage signals arising from the charge conversion of the two in-plane spin polarizations, which have been previously observed at higher temperature. As a result, we report omni-directional spin-to-charge conversion—for all spin polarization orientations—in graphene/MoTe2 heterostructures at low temperatures.
Intermittent pulse amperometry as an effective electrochemical assay of 4-nitrophenol
Authors: Prempinij Waswan , Suginta Wipa , Schulte Albert
Published: July 2023

4-nitrophenol (4-NP) is a precursor of many industrial products and drugs, an environmental pollutant, and is used as a reporter molecule in many enzyme assays and disease biomarker screens. Accordingly, 4-NP analysis is a cross-disciplinary requirement, and we propose intermittent pulse amperometry (IPA) as an alternative to spectrophotometric methods. The sensor signal is acquired by applying 0.5 s pulses of 0.95 V once every 99.5 s during continuous amperometric recordings at 0 V resting potential to drive intermittent 4-NP detection at a diffusion-limited rate. With IPA, sensor surface fouling by polymerization of radical intermediates formed in the anodic oxidation process, which is a severe problem in constant-potential amperometry and voltammetry of phenols, is kept at acceptable minimum by restriction of the time at the potential that produces contamination. Complex potential profiles with electrochemical activation steps and/or electrolyte supplementation with anti-fouling agents are not required. Calibration plots are linear up to 500 μM with a sensitivity of 35 nA μM−1 and a practical detection limit of 10 μM. Model samples of 100 μM 4-NP were assessed with suitable recovery rates, and in a proof-of-principle test as electrochemical readout of an enzyme assay, IPA accurately reported the time course of enzymic release of 4-NP from GlcNAc-4NP, a synthetic substrate of glucosaminidases. Simplicity and high performance are the major features of the proposed electrochemical 4-NP testing, and unless the analytical target is present only at trace levels, the technique is a promising alternative for the evaluation of 4-NP, either as a solution component or as a reporter molecule in enzyme assays.
Influence of experimental methods on the mechanical properties of silk fibers: A systematic literature review and future road map
Authors: Greco Gabriele , Schmuck Benjamin , Jalali S. K. , Pugno Nicola M. , Rising Anna
Published: July 2023

Spider silk fibers are of scientific and industrial interest because of their extraordinary mechanical properties. These properties are normally determined by tensile tests, but the values obtained are dependent on the morphology of the fibers, the test conditions, and the methods by which stress and strain are calculated. Because of this, results from many studies are not directly comparable, which has led to widespread misconceptions in the field. Here, we critically review most of the reports from the past 50 years on spider silk mechanical performance and use artificial spider silk and native silks as models to highlight the effect that different experimental setups have on the fibers' mechanical properties. The results clearly illustrate the importance of carefully evaluating the tensile test methods when comparing the results from different studies. Finally, we suggest a protocol for how to perform tensile tests on silk and biobased fibers.
Thermal annealing of superconducting niobium titanium nitride thin films deposited by plasma-enhanced atomic layer deposition
Authors: González Díaz-Palacio Isabel , Wenskat Marc , Deyu Getnet Kacha , Hillert Wolfgang , Blick Robert H. , Zierold Robert
Published: July 2023

Next-generation superconducting radio frequency (SRF) cavities, based on tailored thin films, would allow for more efficient and sustainable accelerators operating at higher accelerating gradients. In particular, superconductor–insulator–superconductor (SIS) multilayers are proposed as a potential alternative to bulk Nb. In this context, NbTiN stands out as a superconducting candidate. Here, we report our studies on NbTiN thin films grown by plasma-enhanced atomic layer deposition (PEALD) in a supercycle approach on AlN in situ deposited on planar silicon substrates. In detail, different ternary compound compositions and thicknesses have been investigated concerning the elemental composition, the superconducting properties, and the crystallinity of the deposited thin films. Two different post-deposition thermal treatments have been applied to Nb0.75Ti0.25N thin films of different thicknesses. Their effect on the film properties has been evaluated. It has been demonstrated that an optimized post-deposition thermal annealing procedure significantly improves the quality of our PEALD deposited Nb0.75Ti0.25N thin films, achieving the highest superconducting critical temperature (Tc) of 15.9 K obtained for films deposited by atomic layer deposition (ALD) so far and a lower critical field (Hc1) of 213 mT, which overpasses the bulk Nb intrinsic limit of 200 mT. Our studies are a promising first stepping stone on the path toward tailored thin films based SRF cavities.
The Rayleigh–Bénard problem for water with maximum density effects
Authors: Basavarajappa Mahanthesh , Bhatta Dambaru
Published: July 2023

Linear stability and weakly nonlinear stability analyses are developed for Rayleigh–Bénard convection in water near 3.98 °C subject to isothermal boundary conditions. The density–temperature relationship (equation of state) is approximated by a cubic polynomial, including linear, quadratic, and cubic terms. The continuity equation, the Navier–Stokes momentum equation, the equation of state, and the energy equation constitute the governing system. Linear stability analysis is used to investigate how the maximum density property of water affects the onset of convective instability and the choice of unstable wave number for four different types of boundary conditions. Then, a weakly nonlinear stability study is done using the spectral Fourier method for isothermal tangential stress-free boundary conditions to quantify the heat transport of the system and demonstrate the transition from regular/periodic convection to chaotic convection. A Stuart-Ginzburg–Landau equation is obtained using the multiscale expansion method. Streamlines and isotherms are presented and analyzed. The influence of maximum density has been shown to delay the onset of instability and is, therefore, a stabilizing mechanism for thermal instability. Due to the maximum density, the onset of chaotic convection is also delayed. Among four different boundaries, the impermeable rigid boundaries require the highest Rayleigh number for instability to begin. Increasing boundary temperatures advance the onset of chaotic convection and improve the heat transport situation.
Coupling spin defects in hexagonal boron nitride to a microwave cavity
Authors: Tran Thinh N. , Gale Angus , Whitefield Benjamin , Dyakonov Vladimir , Toth Milos , Aharonovich Igor , Kianinia Mehran
Published: July 2023

Optically addressable spin defects in hexagonal boron nitride (hBN) have become a promising platform for quantum sensing. While sensitivity of these defects is limited by their interactions with the spin environment in hBN, inefficient microwave delivery can further reduce their sensitivity. Here, we design and fabricate a microwave double arc resonator for efficient transferring of the microwave field at 3.8 GHz. The spin transitions in the ground state of VB− are coupled to the frequency of the microwave cavity, which result in enhanced optically detected magnetic resonance (ODMR) contrast. In addition, the linewidth of the ODMR signal further reduces, achieving a magnetic field sensitivity as low as 42.4 μT/√Hz. Our robust and scalable device engineering is promising for future employment of spin defects in hBN for quantum sensing.
Pore-scale modeling of water–gas flow in heterogeneous porous media
Authors: Shi Haidong , Zhu Qingyuan , Chen Zhangxin , Li Jing , Feng Dong , Zhang Shengting , Ye Jiawei , Wu Keliu
Published: July 2023

Water–gas flow in heterogeneous porous media is a ubiquitous natural phenomenon. A pore-scale investigation can help to understand the mechanisms of water–gas flow. This study employs a direct simulation method to model the immiscible water–gas flow while tracking the phase interface via the phase-field method. We first verified the mathematical model by layered two-phase flow and capillary intrusion tests. Then, the quartet structure generation set was used to generate a heterogeneous porous media, based on which water–gas displacement was simulated. The characteristics of drainage and imbibition displacements were systematically investigated. Results show that the forced imbibition process shows stable displacement due to cooperative filling, yet with local capillary fingering. Capillary valve effects always exist during the process, making the capillary force act as both driving and resistance forces in heterogeneous porous media. Nevertheless, these pore-scale events inhabit the rapid breakthrough in the small pore-throat zone, ensuring the uniform advancement of the interface. During drainage, viscous fingering in the wide pore-throat zone and capillary fingering in the narrow pore-throat zone are simultaneously observed. Compared with the imbibition process, the water–gas front advances faster due to the smaller viscous force of invading fluid. The phase distribution after drainage displacement at different capillary numbers is quite different due to inconsistent flow patterns. Nevertheless, the final phase saturation of the imbibition process under different capillary numbers is similar, but the area of each type is different. For both the imbibition and drainage processes, the larger the capillary number, the higher the final displacement efficiency.
Temperature dependence of magnetic anisotropy and domain wall tuning in BaTiO3(111)/CoFeB multiferroics
Authors: Hunt R. G. , Franke K. J. A. , Keatley P. S. , Shepley P. M. , Rogers M. , Moore T. A.
Published: July 2023

Artificial multiferroics consist of two types of ferroic materials, typically a ferroelectric and a ferromagnet, often coupled interfacially by magnetostriction induced by the lattice elongations in the ferroelectric. In BaTiO3, the magnitude of strain induced by these elongations is heavily temperature dependent, varying greatly between each of the polar crystal phases and exerting a huge influence over the properties of a coupled magnetic film. Here, we demonstrate that temperature and, thus, strain are effective means of controlling the magnetic anisotropy in BaTiO3(111)/CoFeB heterostructures. We investigate the three polar phases of BaTiO3: tetragonal (T) at room temperature, orthorhombic (O) below 280 K, and rhombohedral (R) below 190 K across a total range of 77–420 K. We find two distinct responses: a step-like change in the anisotropy across the low-temperature phase transitions and a sharp high-temperature reduction around the ferroelectric Curie temperature, measured from hard axis hysteresis loops. Using our measurements of this anisotropy strength, we are then able to show by micromagnetic simulation the behavior of all possible magnetic domain wall states and determine their scaling as a function of temperature. The most significant changes occur in the head-to-head domain wall states, with a maximum change of 210 nm predicted across the entire range, effectively doubling the size of the domain wall as compared to room temperature. Notably, similar changes are seen for both high and low temperatures, which suggests different routes for potential control of magnetic anisotropy and elastically pinned magnetic domain walls.