bluuebunny/crossref_metadata_2025 huggingface dataset:
Test technique for arbitrary length high dielectric sheet materials based on perturbation method
Authors: Wang Hangyu , Yu Chengyong , Zheng Hu , Cheng Jin , Li En
Published: April 2023

In this article, a very effective method is proposed to measure the permittivity of sheet materials with a high dielectric constant and loss. To meet the constraints of the perturbation method, controlling the magnitude of the perturbation by reducing the sample size is necessary. However, this will cause significant changes in the polarization field within the sample and, consequently, affects the accuracy of the calculations. To solve the problem, the effects of the polarized electric field and the non-uniformity of the electric field in the resonant cavity have been considered and an empirical model is developed based on this using curve fitting techniques. Taking the optimized depolarization factor into the resonant perturbation equation, the dielectric properties of arbitrary length of the sample can be accurately calculated when the frequency shift and the quality factor variation are known. Then, the method is validated and analyzed by numerical simulations. Finally, practical tests are carried out on a variety of materials at different sizes, and the results are stable and in excellent agreement with the simulated ones. Therefore, we can conclude that the method can accurately measure the complex permittivity of high dielectric sheet materials.
Chaotic advection in a recirculating flow: Effect of a fluid multiple-flexible-solid interaction
Authors: Prasad Vinay , Sharma Atul , Kulkarni Salil S.
Published: April 2023

This paper deals with chaotic advection due to a two-way interaction between flexible elliptical-solids and a laminar lid-driven cavity flow in two dimensions. The present Fluid multiple-flexible-Solid Interaction study involves various number N(= 1–120) of equal-sized neutrally buoyant elliptical-solids (aspect ratio β = 0.5) such that they result in the total volume fraction Φ = 10 % as in our recent study on single solid, done for non-dimensional shear modulus G ∗ = 0.2 and Reynolds number R e = 100. Results are presented first for flow-induced motion and deformation of the solids and later for chaotic advection of the fluid. After the initial transients, the fluid as well as solid motion (and deformation) attain periodicity for smaller N ≤ 10 while they attain aperiodic states for larger N > 10. Adaptive material tracking (AMT) and Finite-Time Lyapunov Exponent (FTLE)-based Lagrangian dynamical analysis revealed that the chaotic advection increases up to N = 6 and decreases at larger N(= 6–10) for the periodic state. Similar analysis for the transient state revealed an asymptotic increase in the chaotic advection with increasing N ≤ 120. These findings are demonstrated with the help of two types of chaos signatures: exponential growth of material blob’s interface and Lagrangian coherent structures, revealed by the AMT and FTLE, respectively. Our work, which is relevant to several applications, presents a novel technique based on the motion of multiple deformable-solids for enhancement of chaotic advection.
Amplitude-robust metastructure with combined bistable and monostable mechanisms for simultaneously enhanced vibration suppression and energy harvesting
Authors: Xu Che , Chen Shun , Wang Chun H. , Yang Yaowen , Zhao Liya
Published: April 2023

This Letter reports an amplitude-robust nonlinear dual-functional metastructure that combines bistable and monostable-hardening mechanisms in the local resonators for simultaneous energy harvesting and vibration suppression. The concept is verified by experiments using a primary beam with six pairs of piezoelectric cantilevered oscillators and numerical analyses using a fully coupled electromechanical model for varying base vibration acceleration and load resistance. The results show that the design offers a wide bandgap at high accelerations, attenuation of transmission peaks, and generation of power over a broad bandwidth, outperforming its linear, pure bistable, and pure monostable counterparts. The dual-functional capabilities are further quantitatively assessed by using a weighted index that reflects both the vibration and power generation behaviors. This study demonstrates opportunities in development of the smart nonlinear metastructures for simultaneous vibration suppression and energy harvesting.
Characteristics of atmospheric pressure Ar-plasma around a spherical particle: Numerical study
Authors: Krivtsun I. V. , Momot A. I. , Antoniv D. V. , Qin Binhao
Published: April 2023

The characteristics of atmospheric pressure Ar-plasma such as the spatial distributions of number densities, fluxes, and temperatures of electrons and heavy plasma particles, as well as the spatial distribution of electric potential around an individual spherical particle, were studied numerically on the basis of the hydrodynamic (diffusion) equations for plasma components. The governing equations were formulated for plasma that is not in thermal and ionization equilibrium. The boundary conditions near the particle were set on the edge of the space charge layer (sheath) adjacent to the particle surface. The nonlinear problem was solved taking into account the temperature dependencies of transport and kinetic coefficients. The heat flux introduced by the plasma into the particle was calculated and compared with the results of the simple heat conduction model. The range 10 − 5 – 10 − 4 m of particle radius and the range 6–18 kK of unperturbed plasma temperature were considered.
Kinetic reconstruction of free energies as a function of multiple order parameters
Authors: Goswami Yagyik , Sastry Srikanth
Published: April 2023

A vast array of phenomena, ranging from chemical reactions to phase transformations, are analyzed in terms of a free energy surface defined with respect to a single or multiple order parameters. Enhanced sampling methods are typically used, especially in the presence of large free energy barriers, to estimate free energies using biasing protocols and sampling of transition paths. Kinetic reconstructions of free energy barriers of intermediate height have been performed, with respect to a single order parameter, employing the steady state properties of unconstrained simulation trajectories when barrier crossing is achievable with reasonable computational effort. Considering such cases, we describe a method to estimate free energy surfaces with respect to multiple order parameters from a steady state ensemble of trajectories. The approach applies to cases where the transition rates between pairs of order parameter values considered is not affected by the presence of an absorbing boundary, whereas the macroscopic fluxes and sampling probabilities are. We demonstrate the applicability of our prescription on different test cases of random walkers executing Brownian motion in order parameter space with an underlying (free) energy landscape and discuss strategies to improve numerical estimates of the fluxes and sampling. We next use this approach to reconstruct the free energy surface for supercooled liquid silicon with respect to the degree of crystallinity and density, from unconstrained molecular dynamics simulations, and obtain results quantitatively consistent with earlier results from umbrella sampling.
Research on non-Newtonian characteristics of crude oil flow at micro-nano scale
Authors: Song Fuquan , Ding Heying , Huang Lintao , Wang Yong , Sun Yeheng
Published: April 2023

The characteristic scale of flow in micro–nanochannels is generally in the range of 0.01 μm∼1 μm. When crude oil passes through micro-nano channels and tight reservoirs, it shows obvious nonlinear seepage characteristics, which does not conform to the continuity assumption of fluid. Therefore, a non-Newtonian model of crude oil flowing in micro-nano channels and tight reservoirs under the action of shear stress is established, and the relationship between flow rate and apparent viscosity and shear rate is analyzed. The experiment of crude oil flow in micro-nano channels and tight oil reservoir cores shows that the model can be used to describe the nonlinear seepage law of liquid through the nonlinear fitting. The power law index of the oil-phase power-law non-Newtonian fluid is greater than 1 at the micro-nano scale, which conforms to the flow characteristics of the expansive fluid, thus verifying the effectiveness of the non-Newtonian model. In addition, the study of apparent viscosity and shear rate of non-Newtonian fluid shows that the increasing and decreasing trends of flow rate and shear rate and the changing trends of flow rate and pressure gradient are consistent, and shear rate can be used to describe the characteristics of fluid instead of the pressure gradient.
Thermally driven dynamics of interacting droplet-pairs in micro-confined shear flow: Beyond the realm of droplet coalescence
Authors: Das Sayan , Santra Somnath , Chakraborty Suman
Published: April 2023

Pattern formation and dynamics of interacting droplets in confined passages are ubiquitous in a variety of natural, physical, and chemical processes and appears to be contrasting as compared to single droplet dynamics. However, while the dynamical evolution of single droplets under various forces, including their thermally driven motion, has been explored extensively, the concerned physical facets cannot be trivially extended for addressing the motion of multiple droplets. By considering temperature-gradient-driven interfacial transport, here, we unveil four different modes of thermally activated migration of a droplet-pair in microchannels. These include pure reversing motion, sliding-over motion, follow-up motion, and direct coalescence. The presence of follow-up motion, because of the imposed temperature gradient, has not been investigated before. We further put forward the possibility of conversion of one pattern to another by modulating different tuning parameters, such as the wall temperature, channel dimension, and the relative initial positioning of the droplets. These results may turn out to be of profound importance in a wide variety of applications ranging from materials processing to micro-reactor technology.
Mesoporous silica nanoparticle-induced drought tolerance in Arabidopsis thaliana grown under in vitro conditions
Authors: Tran Thi Linh Chi , Guirguis Albert , Jeyachandran Thanojan , Wang Yichao , Cahill David M.
Published: April 2023

Nanoparticles of varying formats and functionalities have been shown to modify and enhance plant growth and development. Nanoparticles may also be used to improve crop production and performance, particularly under adverse environmental conditions such as drought. Nanoparticles composed of silicon dioxide, especially those that are mesoporous (mesoporous silica nanoparticles; MSNs), have been shown to be taken up by plants; yet their potential to improve tolerance to abiotic stress has not been thoroughly examined. In this study, a range of concentrations of MSNs (0–5000 mg L−1) were used to determine their effects, in vitro, on Arabidopsis plants grown under polyethylene glycol (PEG)-simulated drought conditions. Treatment of seeds with MSNs during PEG-simulated drought resulted in higher seed germination and then greater primary root length. However, at the highest tested concentration of 5000 mg L−1, reduced germination was found when seeds were subjected to drought stress. At the optimal concentration of 1500 mg L−1, plants treated with MSNs under non-stressed conditions showed significant increases in root length, number of lateral roots, leaf area and shoot biomass. These findings suggest that MSNs can be used to stimulate plant growth and drought stress tolerance.
A cell-free antigen processing system informs HIV-1 epitope selection and vaccine design
Authors: Sengupta Srona , Zhang Josephine , Reed Madison C. , Yu Jeanna , Kim Aeryon , Boronina Tatiana N. , Board Nathan L. , Wrabl James O. , Shenderov Kevin , Welsh Robin A. , Yang Weiming , Timmons Andrew E. , Hoh Rebecca , Cole Robert N. , Deeks Steven G. , Siliciano Janet D. , Siliciano Robert F. , Sadegh-Nasseri Scheherazade
Published: April 2023

Distinct CD4+ T cell epitopes have been associated with spontaneous control of HIV-1 replication, but analysis of antigen-dependent factors that influence epitope selection is lacking. To examine these factors, we used a cell-free antigen processing system that incorporates soluble HLA-DR (DR1), HLA-DM (DM), cathepsins, and full-length protein antigens for epitope identification by LC-MS/MS. HIV-1 Gag, Pol, Env, Vif, Tat, Rev, and Nef were examined using this system. We identified 35 novel epitopes, including glycopeptides. Epitopes from smaller HIV-1 proteins mapped to regions of low protein stability and higher solvent accessibility. HIV-1 antigens associated with limited CD4+ T cell responses were processed efficiently, while some protective epitopes were inefficiently processed. 55% of epitopes obtained from cell-free processing induced memory CD4+ T cell responses in HIV-1+ donors, including eight of 19 novel epitopes tested. Thus, an in vitro processing system utilizing the components of Class II processing reveals factors influencing epitope selection of HIV-1 and represents an approach to understanding epitope selection from non–HIV-1 antigens.
Composite magnetic 3D-printing filament fabrication protocol opens new perspectives in magnetic hyperthermia
Authors: Makridis A , Okkalidis N , Trygoniaris D , Kazeli K , Angelakeris M
Published: April 2023

Three-dimensional (3D) printing technology has emerged as a promising tool for meticulously fabricated scaffolds with high precision and accuracy, resulting in intricately detailed biomimetic 3D structures. Producing magnetic scaffolds with the aid of additive processes, known as 3D printing, reveals multitude and state-of-the-art areas of application such as tissue engineering, bone repair and regeneration, drug delivery and magnetic hyperthermia. A crucial first step is the development of innovative polymeric composite magnetic materials. The current work presents a fabrication protocol of 3D printed polymer-bonded magnets using the Fused Deposition Modeling 3D printing method. Polymer-bonded magnets are defined as composites with permanent-magnet powder embedded in a polymer binder matrix. By using a low-cost mixing extruder, four (4) different filament types of 1.75 mm were fabricated using commercial magnetite magnetic nanoparticles mixed with a pure polylactic acid powder (PLA) and a ferromagnetic PLA (Iron particles included) filaments. The powder mixture of the basic filaments was compounded mixed with the nanoparticles (NPs), and extruded to fabricate the 3D printing filament, which is subsequently characterized structurally and magnetically before the printing process. Magnetic polymer scaffolds are finally printed using composite filaments of different concentration in magnetite. Our results demonstrate that the heating efficiency (expressed in W g−1) of the 3D printed magnetic polymer scaffolds (ranging from 2 to 5.5 W g−1 at magnetic field intensity of 30 mT and field frequency of 365 kHz) can be tuned by choosing either a magnetic or a non-magnetic filament mixed with an amount of magnetite NPs in different concentrations of 10 or 20 wt%. Our work opens up new perspectives for future research, such as the fabrication of complex structures with suitable ferromagnetic custom-made filaments adjusting the mixing of different filaments for the construction of scaffolds aimed at improving the accuracy of magnetic hyperthermia treatment.
Spin-induced valley polarization in heterobilayer Janus transition-metal dichalcogenides
Authors: Liu Huating , Huang Zongyu , Luo Chaobo , Guo Gencai , Peng Xiangyang , Qi Xiang , Zhong Jianxin
Published: April 2023

Inspired by potential application prospects of spintronics and valleytronics, a novel heterobilayer Janus structure is designed by replacing the chalcogenide atomic layers in the original bilayer MoS2. Based on first-principles calculations, it is found that the SMoS/SeMoS structure exhibits a direct band-gap semiconductor and a typical type-II band alignment with longer carrier lifetime. The transition metal (TM) atom represented by V/Cr/Mn can be stably adsorbed on the heterobilayer Janus SMoS/SeMoS sheet and effectively introduce magnetic moments (m). The calculation results demonstrate that the most stable adsorption site of the TM atom is CX(A), and the TM (V/Cr/Mn) adatom modified SMoS/SeMoS system is converted into metal (V-) or half-metal (Cr/Mn-), respectively. Under the coupling of different indirect exchange interactions, the structure exhibits stable intrinsic anti-ferromagnetic interactions for V-SMoS/SeMoS and ferromagnetic ground state for Cr/Mn-SMoS/SeMoS, respectively, and the magnetic transition temperature (T
c) reaches a high temperature or even room temperature. Moreover, the robust out-of-plane magnetocrystalline anisotropy energy ensures stable long-range magnetic order. Specifically, the combination of spin injection and strong spin–orbit coupling interaction effectively breaks the time-reversal symmetry, which leads to valley polarization of the system. Based on this, the biaxial strain can effectively regulate the electronic structure, magnetic properties and valley polarization of TM-SMoS/SeMoS nanosheets with double breaking of spatial-inversion and time-reversal symmetry.
Challenges with the self-consistent implementation of closure models for anomalous electron transport in fluid simulations of Hall thrusters
Authors: Marks Thomas A , Jorns Benjamin A
Published: April 2023

The performance of closure models for the anomalous electron transport when self-consistently implemented in a fluid model for a Hall effect thruster is investigated. This cross-field transport, which is orders of magnitude higher than classical collisional transport, is represented as an effective collision frequency. The proposed closure models relate this transport coefficient to local fluid properties of the plasma. Before implementation, the models are calibrated against values of the collision frequency inferred empirically from a 9 kW Hall thruster at 300 V and 15 A. It is found that even though closure models match the empirical collision frequency values, they diverge from these values when implemented self-consistently in a Hall thruster code. Possible drivers of this behavior are examined, including the role of non-linearity in the governing equations of the Hall thruster fluid model, artifacts from using time-averaged calibration data, and the non-uniqueness of the empirically-inferred collision frequencies. These results are discussed in the context of their implications for discovering and validating new closures necessary for enabling fully-predictive Hall thruster models.
Chirality-induced directional rotation of a symmetric gear in a bath of chiral active particles
Authors: Li Jing-Ran , Zhu Wei-jing , Li Jia-Jian , Wu Jian-Chun , Ai Bao-Quan
Published: April 2023

We conduct a numerical study exploring the rotation of a symmetric gear driven by chiral particles in a two-dimensional box with periodic boundary conditions. The symmetric gear is submerged in a sea of chiral active particles. Surprisingly, even though the gear is perfectly symmetric, the microscopic random motion of chiral active particles can be converted into macroscopic directional rotation of the gear. (i) In the case of zero alignment interaction, the direction of rotation of the gear is determined by the chirality of active particles. Optimal parameters (the chirality, self-propelled speed, and packing traction) exist, at which the rotational speed reaches its maximum value. (ii) When considering a finite alignment interaction, alignment interactions between particles play an important role in driving the gear to rotate. The direction of rotation is dictated by the competition between the chirality of active particles and the alignment interactions between them. By tuning the system parameters, we can observe multiple rotation reversals. Our findings are relevant to understanding how the macroscopic rotation of a gear connects to the microscopic random motion of active particles.
Topological effects on non-relativistic eigenvalue solutions under AB-flux field with pseudoharmonic- and Mie-type potentials
Authors: Ahmed Faizuddin
Published: April 2023

In this paper, we investigate the quantum dynamics of a non-relativistic particle confined by the Aharonov–Bohm quantum flux field with pseudoharmonic-type potential in the background of topological defect produced by a point-like global monopole. We solve the radial Schrödinger equation analytically and determine the exact eigenvalue solution of the quantum system. Afterwards, we consider a Mie-type potential in the quantum system and solve the radial equation analytically and obtain the eigenvalue solution. We analyze the effects of the topological defect and the quantum flux with these potentials on the energy eigenvalue and wave function of the non-relativistic particles. In fact, it is shown that the energy levels and wave functions are influenced by the topological defect shifted the result compared to the flat space results. In addition, the quantum flux field also shifted the eigenvalue solutions and an analogue of the Aharonov–Bohm effect for bound-states is observed. Finally, we utilize these eigenvalue solutions to some known diatomic molecular potential models and presented the energy eigenvalue and wave function.
Reducing retraction in engineered tissues through design of sequential growth factor treatment
Authors: Lei Ying , Mungai Rozanne , Li Juanyong , Billiar Kristen
Published: April 2023

Heart valve disease is associated with high morbidity and mortality worldwide, resulting in hundreds of thousands of heart valve replacements each year. Tissue engineered heart valves (TEHVs) have the potential to overcome the major limitations of traditional replacement valves; however, leaflet retraction has led to the failure of TEHVs in preclinical studies. Sequentially varying growth factors over time has been utilized to promote maturation of engineered tissues and may be effective in reducing tissue retraction, yet it is difficult to predict the effects of such treatments due to complex interactions between the cells and the extracellular matrix (ECM), biochemical environment, and mechanical stimuli. We hypothesize that sequential treatments of fibroblast growth factor 2 (FGF-2) and transforming growth factor beta 1 (TGF-β1) can be used to minimize cell-generated tissue retraction by decreasing active cell contractile forces exerted on the ECM and by inducing the cells to increase the ECM stiffness. Using a custom culturing and monitoring system for 3D tissue constructs, we designed and tested various TGF-β1 and FGF-2 based growth factor treatments, and successfully reduced tissue retraction by 85% and increased the ECM elastic modulus by 260% compared to non-growth factor treated controls, without significantly increasing the contractile force. We also developed and verified a mathematical model to predict the effects of various temporal variations in growth factor treatments and analyzed relationships between tissue properties, the contractile forces, and retraction. These findings improve our understanding of growth factor-induced cell-ECM biomechanical interactions, which can inform the design of next generation TEHVs with reduced retraction. The mathematical models could also potentially be applied toward fast screening and optimizing growth factors for use in the treatment of diseases including fibrosis.
Experimental investigation of additive free-low-cost vinyl triarylamines based hole transport material for FAPbI3-based perovskite solar cells to enhance efficiency and stability
Authors: Kumar Anjan , Singh Sangeeta , Mohammed Mustafa K A , Ahmed Duha S
Published: April 2023

Perovskite-based solar cells have drawn a lot of attention recently because they possess many desirable qualities, including strong photon absorption, large carrier lifetime, ambipolar transmission, and low exciton binding energy. With continual optimization of each functional layer, particularly the active layer and hole transporting layer, the power conversion efficiency (PCE) of perovskite materials has reached over 25%. Spiro-OMeTAD is a widely utilized hole transport material (HTM) for efficient solar cell operation. To improve conductivity, this material is often doped with additives such as 4-tert-butylpyridine (TBP) or bis(trifluoromethane)sulfonimide lithium salt (Li-TFSI). Unfortunately, these additives can weaken the perovskite layer and reduce device stability. In this work, we enhanced the efficiency as well as stability of formamidinium-based perovskite using additive-free, cost-effective HTM based on vinyl triarylamines developed by the Tokyo chemical industry. We have deposited vinyl triarylamines-based HTM on both FAPbI3 and MAPbI3 perovskite. To compare the results, we have deposited traditional additive-based as well as additive free Spiro-OMeTAD on FAPbI3 perovskite. Results are encouraging as the FAPbI3-based device showed a decent power conversion efficiency of 16.86%, which is higher than when the same HTM is deposited on the MAPbI3-based device and comparable with doped Spiro-OMeTAD and much higher than undoped Spiro-OMeTAD based HTM deposited on FAPbI3 perovskite. Enhancement in device performance is attributed to better hole mobility and favourable energy band positioning of vinyl triarylamines based hole transport layer w.r.t FAPbI3 perovskite. The PCE of a FAPbI3-based device using the suggested HTM (SHTM) suffers only a 12% decrease while following the maximum power point for 1800 h in ambient air.
Superconductor spin-correlation measured
Authors: Jarman Sam
Published: April 2023

Physicists in Switzerland and Italy have shown that the spins of two electrons in a Cooper pair have a negative correlation, so they tend to point in opposite directions.
Petal colour found to oscillate over time to improve pollination
Authors: Jarman Sam
Published: April 2023

A rare case of a flower that oscillates in colour over time has been discovered by researchers in Japan.
Quantum sensor survives at record-high pressures
Authors: Dumé Isabella
Published: April 2023

Quantum sensors based on microscopic flaws in the crystalline structure of diamond can work at pressures as high as 140 GPa, say Chinese researchers.
UK space launch fails to reach orbit
Authors: Skuse Benjamin
Published: April 2023

The first space launch from UK soil ended in failure when the rocket suffered an anomaly preventing it from reaching orbit.
Bridging the class divide
Authors: Follows Mike
Published: April 2023

Mike Follows argues that class prejudice can have an equally devastating effect in science as other forms of discrimination.
Einstein as you’ve never seen him
Authors: Robinson Andrew
Published: April 2023

Andrew Robinson reviews Einstein: the Man and His Mind by Gary S Berger and Michael DiRuggiero.
As my wine glass gently weeps
Authors: Commissariat Tushna
Published: April 2023

Tushna Commissariat ponders the surprising fluid dynamics of wine.
UK kicks off X-ray laser design
Authors: Banks Michael
Published: April 2023

Researchers have started work on the conceptual design review for a new UK-based X-ray free-electron laser to see what science the facility should focus on. Michael Banks reports.
Enter the chatbot revolution
Authors: Johnston Hamish
Published: April 2023

Theoretical physicist Matt Hodgson from the University of York talks to Hamish Johnston about the role that large language models, or chatbots, can play in physics.
It happens more than you think
Authors: Green Karel
Published: April 2023

Doing a PhD in physics ought to be a wonderful and fulfilling experience as you embark on real research for the first time. But as Karel Green discovered, the reality is very different, especially for the current cohort of students, who have had to battle their way through the COVID-19 pandemic.
The surprising physics of babies
Authors: Banks Michael
Published: April 2023

There is much to learn when it comes to applying the tools of physics to conception, pregnancy and babyhood, as Michael Banks explains.
From tech fear to tech leader
Authors: Gardner Kate
Published: April 2023

Kate Gardner reviews She’s in CTRL: How Women Can Take Back Tech by Anne-Marie Imafidon.
Design of an adaptive power controller for improving THD performance of integrated-parallel buck-boost converter via efficient reverse power routing
Authors: Mutta Chandini , Goswami Agam Das
Published: April 2023

Parallel buck-boost converters are high-output DC-to-DC converters. It is increased by inverting the voltage and decreasing the circuit current capacity. The duty cycle of switching transistors governs converter voltage. Output current moderates THD in these converters. Additional current losses cause output voltage and current harmonics. Inductors, capacitors, MOSFETs, and other power control filtering models reduce excessive current and THD. Complex models lose scalability and stability. Real-time buck-boost controllers can’t use them. Filtered adaptive power controller blocks reduce buck-boost converter response time and inject improper frequency components at the output. A reverse power routing model with an adaptive power controller is proposed to estimate excessive output power and improve converter performance. Reverse power control lowers THD by 20% and increases power throughput. When output power drops, the adaptive power controller (APC) changes ON/OFF duty cycles. The proposed model reduced THD and maintained high output voltage and current in both continuous and discontinuous modes. Context-aware circuit design measured output ripples, harmonics, smoothness factor, and power loss. The proposed parallel buck-boost converter had 10% lower jitters, 23% better harmonic outputs, 15% better smoothness, and 5% lower total power loss than others. The model handles high-density electrical loads with maximum power throughput.
Community-based water demand management: socio-technical strategies for improving water security in Australian Indigenous communities
Authors: Beal C D , Bailey M-S , Hohenhaus M , Jackson M
Published: April 2023

Sustainable water management in remote Australian communities is a delicate balance between sufficient and acceptable supply options and appropriate and effective demand approaches. This paper focus on the evaluation of community-based water demand management strategies piloted in four remote Aboriginal and Torres Strait Island communities in Australia. Findings of the pilot demonstrate that from a systems perspective, community-based demand management centred around education and encouragement of residents to conserve and use water efficiently, provide greater opportunities for long-term sustainable water management outcomes that support building of social capital. To ensure truly transformative management outcomes, a toolbox of socio-technological strategies should be used including, where possible, smart metering of water consumption and use of water-efficient devices. A key element of this approach to demand management calls for a shift away from business-as-usual policy towards a flexible learning approach that involves genuine collaboration between water managers and Indigenous communities.
The rapid rise of severe marine heat wave systems
Authors: Prochaska J Xavier , Beaulieu Claudie , Giamalaki Katerina
Published: April 2023

We introduce a new methodology to study marine heat waves (MHWs), extreme events in the sea surface temperature (SST) of the global ocean. Motivated by previously large and impactful MHWs and by theoretical expectation that the dominant heating processes coherently affect large regions of the ocean, we introduce a methodology from computer vision to construct marine heat wave systems (MWHSs) – the collation of SST extrema in dimensions of area and time. We identify 649 475 MHWSs in the 37 year period (1983–2019) of daily SST records and find that the duration

t

d
u
r

(days), maximum area

A

m
a
x

(km2), and total ‘volume’

V

M
H
W
S

(days km2) for the majority of MHWSs are well-described by power-law distributions:

t

d
u
r

−
3

,

A

m
a
x

−
2

and

V

M
H
W
S

−
2

. These characteristics confirm SST extrema exhibit strong spatial coherence that define the formation and evolution of MHWs. Furthermore, the most severe MHWSs deviate from these power-laws and are the dominant manifestation of MHWs: extrema in ocean heating are driven by the

∼

200

systems with largest area and duration. We further demonstrate that the previously purported rise in the incidence of MHW events over the past decade is only significant in these severe systems. A change point analysis reveals a rapid increase in days under a severe MHW in most regions of the global ocean over the period of 2000–2005. Understanding the origin and impacts of MHWs in the current and future ocean, therefore, should focus on the production and evolution of the largest-scale and longest-duration heating phenomena.
Association between traffic-related air pollution exposure and fertility-assisted births
Authors: Thampy Daphne , Vieira Verónica M
Published: April 2023

Previous studies have suggested that traffic-related air pollution is associated with adverse fertility outcomes, such as reduced fecundability and subfertility. The purpose of this research is to investigate if PM2.5 exposure prior to conception or traffic-related exposures (traffic density and distance to nearest major roadway) at birth address is associated with fertility-assisted births. We obtained all live and still births from the Massachusetts state birth registry with an estimated conception date between January 2002 through December 2008. All births requiring fertility drugs or assisted reproductive technology were identified as cases. We randomly selected 2000 infants conceived each year to serve as a common control group. PM2.5 exposure was assessed using 4 km spatial satellite remote sensing, meteorological and land use spatiotemporal models at geocoded birth addresses for the year prior to conception. The mean PM2.5 level was 9.81 µg m−3 (standard deviation = 1.70 µg m−3), with a maximum of 14.27 µg m−3. We calculated crude and adjusted fertility treatment odds ratios (ORs) and 95% confidence intervals (CI) per interquartile range of 1.72 µg m−3 increase in PM2.5 exposure. Our final analyses included 10 748 fertility-assisted births and 12 225 controls. After adjusting for parental age, marital status, race, maternal education, insurance status, parity, and year of birth, average PM2.5 exposure during the year prior to conception was weakly associated with fertility treatment (OR: 1.01; 95% CI: 0.97, 1.05). Fertility-assisted births were inversely associated with traffic density (highest quartile compared to lowest quartile, OR: 0.92; 95% CI: 0.83, 1.02) and positively associated with distance from major roadway (OR per 100 m: 1.01; 95% CI: 1.00, 1.02) in adjusted analyses. We did not find strong evidence to support an adverse relationship between traffic-related air pollution exposure and fertility-assisted births.
Lying: revisiting the ‘intending to deceive’ condition
Authors: Krstić Vladimir
Published: April 2023

This paper refines the received analysis of deceptive lies. This is done by assessing some cases of lies that are supposedly not intended to deceive and by arguing that they actually involve sophisticated strategies of intentional deception. These lies, that is, merely seem not to be intended to deceive and this is because our received analysis of deceptive lies is insufficiently sophisticated. We need to add these strategies to our analysis of deceptive lying. The argument ends by presenting this refined analysis.
Assessing Readability of FDA-Required Labeling for Breast Implants
Authors: Powell Lauren , Krivanek Taylor , Deshpande Sagar , Landis George
Published: April 2023

Goals/Purpose

In 2021, the United States (US) Food and Drug Administration (FDA) introduced regulations to improve the delivery of breast implant patient education, including new labeling requirements. The new regulations called for a patient decision checklist to be reviewed with a physician ahead of surgery. To ensure educational materials are accessible to most patients, the National Institutes of Health recommend they be written at a sixth to seventh grade level. This study aims to assess the readability of patient-facing FDA labeling for breast implants.

Methods/Technique

Eleven patient information brochures and seven patient decision checklists were obtained from four breast implant company websites. An example checklist was also obtained from the FDA website. Plain text was extracted from each of the documents. Figures, tables, references, and indices were omitted. The text files were analyzed using four measures of readability validated in clinical materials: Flesch-Kincaid Grade Level, Coleman-Liau Index, Simplified Measure of Gobbledygook (SMOG), and Automated Readability Index (ARI).

Results/Complications

On average, patient information brochures were 73 pages long (range: 48-92) and included 8 figures or graphics, while patient decision checklists were 5.7 pages long (range: 4-7) and included 0 figures or graphics. Mean readability scores of brochures were a Flesch-Kincaid of 12.7, Coleman-Liau Index of 13.0, SMOG of 14.0, and ARI of 12.7, with an overall mean grade level of 13.1 (13th grade). For decision checklists, results showed a Flesch-Kincaid of 14.2, Coleman-Liau Index of 13.3, SMOG of 15.6, and ARI of 14.8, with an overall grade level of 14.5 (14-15th grade). Comparatively, the sample decision checklist published by the FDA had a Flesch-Kincaid of 13.9, Coleman-Liau Index of 13.0, SMOG of 15.5, and ARI of 14.4, with an overall grade level of 14.2 (14th grade).

Conclusion

Although patient decision checklists were introduced to improve accessibility of breast implant educational materials, the level at which they are written exceeds the recommendation for the average US adult by several grade levels, suggesting that patients may not fully understand current materials. While shorter than the comprehensive information brochures available, decision checklists were more difficult to read across all readability scales assessed in this study, and neither brochures nor checklists met recommended reading levels on any of the assessed scales. In order to encourage patient understanding of surgical and implant risks and promote the positive health outcomes, the FDA and breast implant companies may consider revising labeling materials.
Exploring the Financial, Psychological, and Operative Factors Associated With Implant Removal Satisfaction in Breast Implant Illness Patients
Authors: Bascone Corey , Couto Javier , Reed McGraw J , Sulkar Reena , Broach Robyn , Butler Paris , Kovach Stephen
Published: April 2023

Goals/Purpose

Breast implant illness (BII) is a poorly understood heterogeneous disorder treated with implant removal; however, patient-reported symptoms and outcomes following treatment remain unclear.

Methods/Technique

A retrospective review of patients undergoing bilateral breast implant removal related to BII by two surgeons between 2018-2022 was performed. Patients were surveyed with the BREAST-Q augmentation model with the American Society of Plastic Surgeons (ASPS) BII survey extension. Outcomes were analyzed using a multivariable logistic regression adjusting for patient-associated factors.

Results/Complications

Forty-seven patients were surveyed with a response rate of 51% (n=24). Of the 20 patients completing the survey, the majority were Caucasian (85%), with 45% (n=9) having a documented history of psychiatric illness. Six (30%) had capsular contracture and four (20%) had documented implant rupture. The majority of implant removals (n=12, 60%) were not covered by insurance. Fourteen (70%) had a net improvement in their symptoms after implant removal—most commonly improving chest discomfort, muscle pain, fever, and headaches. Self-pay was predictive of increased breast satisfaction scores (p=0.009), but had no impact on symptomatic improvement. Reduced time to implant removal was predictive of fewer residual symptoms (p=0.032). Capsular contracture was predictive of reduced psychosocial, sexual, and breast satisfaction scores (p=0.015). Psychiatric illness had no significant impact on outcomes.

Conclusion

In the setting of suspected or diagnosed BII, reduced time to implant removal may decrease the risk of residual symptoms and improve overall patient satisfaction. In patients with capsular contracture, preoperative counseling should emphasize the fact that implant removal may improve physical symptoms only.
Ultrasound-Guided Transversus Abdominis Plane (TAP) Blocks Vs. Local Infiltration Anesthesia on Post Anesthesia Care Unit (PACU) Pain Control
Authors: Puyana Salomon , Heffern Jadyn , Harvak Hajebian H , Kresofsky Kevin , Chaffin Abigail , Lindsey John
Published: April 2023

Goals/Purpose

Ultrasound-guided regional field blocks are not widely used in outpatient plastic surgery.1 These blocks have been shown to significantly decrease the number of prescribed opioids in patients who underwent abdominoplasty, liposuction, and primary submuscular breast operations. 2,3 The goal of this study is to compare ultrasound-guided TAP blocks to local infiltration anesthesia with or without blind rectus sheath blocks in patients undergoing abdominoplasty.

Methods/Technique

A retrospective review was conducted of patients undergoing outpatient abdominoplasty performed by the senior surgeon. Group 1 (Local) received local infiltration anesthesia with or without blind rectus sheath blocks between April 2009 and December 2013. Group 2 (TAP) received surgeon-led, intraoperative, ultrasound-guided, 4-quadrant TAP blocks between January 2014 and December 2021. Outcomes measured included opioid utilization, morphine milligram equivalents (MME) and pain level at discharge (scale from 1 to 10).

All abdominoplasties were performed using the same suture materials and techniques by the senior surgeon in the same accredited outpatient surgical facility. Abdominoplasty technique included supraumbilical undermining, umbilical transposition, rectus abdominis fascial plication, progressive tension sutures, and liposuction of the flanks. Patients were excluded if other procedures were performed at the time of abdominoplasty.

Results/Complications

60 patients in each of the two study groups met the study criteria for a total of 120 patients. The study groups were similar except for a lower average age in group 1 (Table 1). Patients receiving TAP blocks (group 2) had significantly lower MME requirements in the PACU (3.48 v 2.21, p=0.005). There was no difference in pain level at discharge between the two groups (2.35 v 2.17, p=0.624), (Table 1).

Conclusion

Surgeon-led, intraoperative, ultrasound-guided, 4-quadrant TAP blocks statistically significantly reduced opioid utilization by 36.5% in the PACU while achieving comparable patient pain scores.
From a Single Penile Suspensory Ligament to a Penile Suspensory Apparatus: Application to the Buried Penis Surgery
Authors: Laurent Romain , Danino Ruben Pierre , Trouilloud Pierre , Benkhadra Mehdi , Danino Michel Alain
Published: April 2023

Goals/Purpose

The ligamentous system supporting the penis is widely called « penile suspensory ligament ». It supports and attaches the penis to the abdominal wall and the pubic bone. However, the complexity of the anatomy of the penile suspensory system was underestimated. The aim of this anatomical study was to describe the different ligamentous (features, insertion sites, path) and their functions.

Methods/Technique

The first step consisted in a description of the different components of the penile suspensory apparatus on two cadavers embalmed by the Thiel method. The second part was an evaluation of the function of each ligament on freshly dead cadavers. In the third stage, we applied those findings to an exploratory cohort of patients undergoing a penile lengthening surgery for buried penis.

Results/Complications

The penile suspensory apparatus consisted in four ligaments from anterior to posterior : the fundiform ligament, the suspensory ligament, dense vertical ligament and the arcuate ligament. The first two were loose, non-stabilizing and the two posterior ones were dense and stabilizing. In our cohort, 12 patients were included. The mean BMI was 38. The mean pre-operative flaccid length was 4.1 cm [2.2 cm – 7 cm] and at 6 months 8.2 cm [5.2 cm - 11.5 cm] which represents a mean augmentation of 100%. The mean pre-operative circumference at a flaccid state was 8.2 cm [2 cm – 11.5 cm] and at 6 months post-operative was 12.6 cm [8.3 cm - 16 cm] which represents a mean augmentation of 85.7%. The most common complication was a phimosis.

Conclusion

We have described the detailed anatomy of the penile suspensory apparatus. It is the first time that the dense vertical ligament was brought to light. To avoid instability in penile lengthening, the posterior part of the dense vertical ligament and the arcuate ligament must be spared.
Nestling mouth colors mediate parental favoritism but do not influence detectability
Authors: Border Shana E , Haas Liana E , Steines Madison E , Dugas Matthew B
Published: April 2023

Young animals often solicit care from their parents using behaviors and morphologies collectively termed begging. Many nestling altricial birds add to their familiar postures and vocalizations by displaying colorful mouthparts, hypothesized to enhance their visual conspicuousness and/or be favored by choosy parents. We evaluated these two hypotheses with experimental manipulations of the flange tissue of house sparrow (Passer domesticus) nestlings. We allowed parents to interact with nestlings that appeared to have either carotenoid-rich or carotenoid-poor flanges, and then with nestlings that appeared similar in carotenoid-richness but differed in either brightness (total light reflected) or ultraviolet (UV) richness. These three features of flange color comprise much of the variation observed both within and among species. None of our three manipulations shaped parents’ ability to transfer prey efficiently to nestlings, a proxy for how visually detectable nestlings were. Parents preferentially allocated prey to nestlings that appeared carotenoid-rich, but did not bias allocation when we manipulated brightness or UV reflectance. These patterns suggest that nestlings displaying carotenoid-rich flanges benefit from parental favoritism, but that variation in brightness and UV reflectance do not independently shape parental care, at least within the range a house sparrow parent might encounter in nature. Efforts to understand mouth color in the context of offspring-parent communication and visual signal evolution may benefit from considering the component parts of color, as they may function, be constrained, and evolve independently.
Muscle mass, creatinine, cystatin C and selective glomerular hypofiltration syndromes
Authors: Malmgren Linnea , Grubb Anders
Published: April 2023

In this issue of Clinical Kidney Journal, Stehlé and colleagues demonstrate that estimation of glomerular filtration rate (GFR) by use of creatinine and a measure, total lumbar muscle cross-sectional area, reflecting the total muscle mass of an individual, is superior to GFR-estimating equations based upon creatinine and demographic variables. The report by Stehlé et al. demonstrates one solution to the interference of muscle mass in the use of creatinine to estimate GFR. This interference was identified already at the start, in 1959, of using creatinine for estimation of GFR. Different ways of taking the muscle mass into account when creatinine-based estimations of GFR have been used generally include use of controversial race and sex coefficients. A new marker of GFR, cystatin C, introduced in 1979, has been shown to be virtually uninfluenced by muscle mass. In this editorial, the simultaneous use of creatinine and cystatin C to estimate GFR, muscle mass and selective glomerular hypofiltration syndromes is described.