bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficiency Improvement in Sugar Mills; The Role of High-Pressure Boiler Technology in Cogeneration
Authors: Umer Muhammad , Mesum Inaam Ullah , Zahid Abdullah Hashim
Published: June 2023

Pakistan’s electricity shortage has had a significant impact on its economic growth, people’s livelihoods, and industrial operations. Currently, thermal methods like oil and gas satisfy around 67% of its electricity needs, with hydropower generating 30% and nuclear means generating only 3%. Bagasse, a solid waste produced during sugar production, accounts for only 0.9% of Pakistan’s energy production. However, by implementing co-generation retrofits, bagasse’s capacity can increase up to 3000 MW. Sugarcane is a significant crop in Pakistan, and sugarcane crushing mills have been utilizing boiler technology for many decades as a means of generating steam and producing electricity. The process of cogeneration, which uses bagasse to generate steam and produce electricity, has several advantages, including reducing reliance on fossil fuels, providing a reliable source of electricity, and a source of revenue for sugarcane mills. High-pressure boilers have several advantages, including higher energy efficiency, higher electricity generation, less wear and tear on equipment, lower installation and maintenance costs, and a smaller footprint. As most sugar mills are in rural areas so we can also use this as a benefit and & provide electricity to remote areas. A case study related to JDW Sugar mill has been added at the end to compare the results of High- and Low-pressure boilers. From the results, it is clear that if we want to have highly efficient Cogeneration scheme in Sugar mills, we need to shift urgently towards High pressure boilers.
E-Ink; Revolution of Displays
Authors: Ali Rabbani Saghar , Ahmed Maaz , Hashim Zahid Abdullah
Published: June 2023

The emergence of digital technology has transformed the way we consume and interact with media, with one of the most significant innovations being the development of e-ink displays. These displays replicate the appearance of ink on paper, providing a low-power, high-contrast alternative to traditional backlit LCD screens. As a result of their advantages such as easy readability, low power consumption, and customization options, e-ink displays have gained widespread adoption in a range of devices such as e-readers, smartwatches, public signage, and transportation timetables. This paper aims to provide a comprehensive understanding of e-ink displays by examining their history, technology, current applications, advantages, and limitations. Additionally, the paper discusses the environmental and cost benefits of e-ink displays in contrast to traditional print media. The role e-ink displays can play in reducing paper waste and carbon emissions is emphasized. By exploring the unique features and benefits of e-ink displays, this paper provides a comprehensive overview of this important technology and its impact on the digital landscape.
Development and Characterization of Boron-Nitride Reinforced Nickel Matrix Composites
Authors: Uz Zaman Atteeq , Khan Awais , Zaman Fatima , Khan Muhammad Moheen , Farooq Umar , Shehbaz Tauheed , Karim Muhammad Ramzan Abdul
Published: June 2023

In this work, pure nickel was reinforced with various contents of h-BN (4 & 8wt.%) and SiC (2, 4, 6 & 8wt.%) prepared via PM route. The synergistic effect of h-BN and SiC on mechanical and microstructural behaviour was investigated. The microstructure and crystal structure were characterized by scanning electron microscope and X-ray diffractometer. The density and microhardness were eveluated via He pycnometer and microhardness tester. SEM results revealed that the exfoliation reduced the particle size of h-BN from approximately 105 nm to 30-40 nm. Furthermore, the addition of h-BN and SiC improved the mechanical properties of the composite. The maximum hardness value of 420 HV was obtained for Ni-8BN-6SiC. This improvement in hardness was attributed to uniform dispersion and high hardness of h-BN and SiC. However, more addition of SiC (>6 wt.%) deteriorated the hardness of the composite due to generated porosity.
Kontrastmittelsonografie eines fibrolamellären hepatozellulären Karzinoms
Authors: Wildner Dane , Schlitt Hans Jürgen , Bäuerle Tobias , Haibach Martina
Published: June 2023

Wir berichten über einen 24-jährigen Patienten, der sich mit anhaltenden Oberbauchschmerzen, Übelkeit und Völlegefühl ohne Erbrechen seit 5 Monaten zur ambulanten endoskopischen Diagnostik vorstellte. Bei der körperlichen Untersuchung fiel eine Verhärtung im Epigastrium ohne Druckschmerzhaftigkeit auf. Endoskopisch zeigte sich lediglich eine Impression des Bulbus duodeni bei intakter Duodenalschleimhaut. Darüber hinaus lagen unauffällige Befunde in Gastroskopie und Ileokoloskopie vor. Abdomensonografisch zeigte sich im linken Leberlappen eine große inhomogene Raumforderung mit scharfer, unregelmäßiger Begrenzung. Der rechte Leberlappen wies eine komplett unauffällige Sonomorphologie auf, insbesondere keine Zeichen des Parenchymschadens oder einer Leberzirrhose. Entlang der oberen mesenterialen Gefäße stellten sich mehrere vergrößerte Lymphknoten mit Kontakt zum Bulbus duodeni dar. In der Kontrastmittelsonografie (CE-US) zeigte die Leberläsion das typische Perfusionsmuster eines hepatozellulären Karzinoms. Zur Klärung des malignitätsverdächtigen Befunds wurde eine sonografisch gesteuerte Stanzbiopsie durchgeführt. Die histopathologische Aufarbeitung ergab den Befund eines hepatozellulären Karzinoms vom fibrolamellären Subtyp.

Mit diesem Fallbericht möchten wir zeigen, dass das HCC vom fibrolamellären Subtyp, trotz einer starken kollagenreichen bindegewebigen Stromakomponente in der Histopathologie, ein HCC-typisches Perfusionsmuster in der KM-Sonografie aufweist.
Metabolisches Syndrom
Authors: Schmidt Robert
Published: June 2023

In unserer Gesellschaft nehmen die Zivilisationskrankheiten zu, und dieser Trend wird sich eher verstärken als abschwächen. In diesem Zusammenhang ist auch das metabolische Syndrom zu nennen, dessen Erstmanifestation in einer Adipositas liegt. Risikofaktoren sind eine hyperkalorische Kost sowie Bewegungs- und Schlafmangel. Mögliche Komplikationen sind kardiovaskuläre Ereignisse und eine generell gesteigerte Mortalität. Komplementärmedizinisch können dem metabolischen Syndrom verschiedene Behandlungsverfahren entgegengesetzt werden. Die naturheilkundlichen Maßnahmen sind als zusätzliche Maßnahmen zu konventionellen Therapien zu verstehen. Der erste Schritt besteht in der Kalorienreduktion sowie in einer Änderung der Ernährungsweise und mehr Bewegung im Alltag. Idealerweise sollten durch die Behandlung langfristig Normwerte erreicht werden. Der Beitrag zeigt auch anhand eines Fallbeispiels, wie die stationäre Behandlung des metabolischen Syndroms am Krankenhaus für Naturheilweisen in München erfolgt.
Preliminary Study on the Expression of CLLD7 and CHC1L Proteins in Oral Squamous Cell Carcinoma
Authors: Klongnoi Boworn , Bhattarai Bishwa Prakash , Juengsomjit Rachai , Meesakul Ounruean , Poomsawat Sopee , Janebodin Kajohnkiart , Khovidhunkit Siribang-on Piboonniyom
Published: June 2023

Objective This study aimed to preliminarily evaluate the expression of two putative tumor suppressor proteins, including chronic lymphocytic leukemia deletion gene 7 (CLLD7) and chromosome condensation 1-like (CHC1L) proteins in oral squamous cell carcinoma (OSCC).

Materials and Methods Expression of CLLD7 and CHC1L proteins was analyzed in 19 OSCC and 12 normal oral mucosa (NOM) using immunohistochemistry. The percentage of positive cells and intensity of staining were semiquantitatively assessed and expressed with an immunoreactive score. The number of positive cells at various subcellular localizations was evaluated and presented in percentages. The immunoreactivity scores and percentages of positive cells at various localizations were compared between the normal and OSCC groups with statistical significance at p-value less than 0.05.

Results According to immunohistochemical analysis, the immunoreactivity scores for both CLLD7 and CHC1L were higher in NOM than those of OSCC. Analysis of CLLD7 localization revealed predominant nuclear staining at basal and parabasal areas in NOM, whereas more cytoplasmic staining was observed in OSCC. For CHC1L, nuclear staining was prominent in NOM. In contrast, significantly increased plasma membrane staining was detected in OSCC.

Conclusion The expression of CLLD7 and CHC1L proteins was reduced in OSCC. Alterations in the subcellular localization of these two proteins in OSCC were also demonstrated. These preliminary results suggest that CLLD7 and CHC1L are aberrantly expressed in OSCC. The precise mechanisms of these putative tumor suppressor proteins in OSCC require future studies.
Optimal Treatment Timing in Orthodontics: A Scoping Review
Authors: Hamidaddin Mohammad A.
Published: June 2023

The appropriate timing for orthodontic intervention has been a subject of debate for a long time, concerning not only the immediate effects but also the long-term benefits of such treatment. This review aimed to find the appropriate treatment timing for the intervention of various orthodontic problems. A literature search was performed in all major databases, including PubMed and Cochrane Library, until February 20, 2023. All observational and experimental studies published in English that compared early versus late orthodontic treatment in different types of orthodontic problems were included. Data selection and charting were undertaken by a single investigator. A total of 32 studies were identified that discussed various aspects of interventions, including Class II and Class III malocclusion, pseudo-Class III malocclusion, anterior and posterior crossbite, extractions, and long-term benefits. Overall, early intervention was not found to be superior in terms of effectiveness, overall duration of appliances, and cost–benefit ratio. Early intervention should be reserved for specific conditions or localized malocclusions that have psycho-social benefits, or to significantly reduce the severity of problems to be dealt with in comprehensive treatment in the permanent dentition.
Nephroprotective Potential of Sphaeranthus indicus Linn Extract against Hyperglycemia and Dyslipidemia in Streptozotocin-Induced Diabetic Nephropathy
Authors: Jadhav Vishal B. , Vaghela Jai Singh
Published: June 2023

Objective This study was aimed at determining the nephroprotective potential of Sphaeranthus indicus Linn methanol extract (SME) against hyperglycemia and dyslipidemia in streptozotocin (STZ)-induced diabetic nephropathy (DNP) in adult Wistar albino rats.

Materials and Methods Following STZ-induced diabetes, adult albino Wistar rats of either sex with serum glucose level more than 250 mg/dL were chosen and randomized into six groups (n = 6 rats per group) and received the treatment as follows: Group I: Normal nondiabetic (ND) rats received a single intraperitoneal dose of citrate buffer in the same volume as STZ and 1% (w/v) carboxymethyl cellulose (CMC) per os (po), group II: diabetic (STZ) control rats received oral dosage of 1% (w/v) CMC, group III, IV and V: STZ + SME treated rats received a suspension of SME (100, 200, and 400 mg/kg, po) in 1% (w/v) CMC, and group VI: STZ + MET treated rats received metformin (500 mg/kg, po) as suspension in 1% (w/v) CMC. From 28th day to the 56th day of STZ injection, SME and MET were given for 28 days in the form of freshly prepared suspension. The impact of STZ-induced DNP was analyzed through the estimation of body weight, serum glucose, and hemoglobin A1c levels, renal functional parameters, the serum lipid profile, oxidative stress markers, and analysis of renal histoarchitecture.

Result Diabetic (STZ) control rats showed significant alterations in body weight, serum glucose and hemoglobin A1c levels, renal functional parameters, the serum lipid profile, oxidative stress markers, and renal histoarchitecture in contrast to normal ND rats. SME and MET treatment significantly reduced hyperglycemia-induced enhanced lipid profile and oxidative stress, normalized renal functional parameters, and restored renal histoarchitecture by reducing vacuolar degeneration of renal tubules in contrast to diabetic (STZ) control rats. These findings were attributed to SME's efficacy in DNP.

Conclusion In STZ-sensitized diabetic rats, SME retarded the progress of nephropathy. The observed nephroprotective potential of SME is ascribed to its hypoglycemic, hypolipidemic, and antioxidant activities.
The Rise and Efficiency of Low Field Portable MRI Scanners
Authors: Pires Tancia , M.M Jaseemudheen
Published: June 2023

Since the discovery of magnetic resonance imaging (MRI) as an imaging modality, it has evolved immensely and is still doing so. Most imaging modalities have made bedside or emergency imaging possible due to their portability. This aspect is yet to be fully evaluated and established in the case of MRI as its high-field strength requires specialized infrastructure and its time-consuming nature makes its portability questionable. The goal of this review is to access the efficiency and feasibility of low-field portable MRI (pMRI) systems in a wide array of health care applications. Articles from indexed journals, on PubMed, Springer, Elsevier, etc. databases, relevant to this study were searched and reviewed. This review provides an atypical design that could be used in making a pMRI unit that could find its potential in diagnosing a wide variety of pathologies with an added advantage of imaging critical patients in the intensive care unit or patients in isolation due to its portability, imaging patients with implants or prosthesis effectively due to its low field, pediatric imaging due to its high speed, for guided interventions, imaging obese and claustrophobic patients due to its open nature, in dental imaging, extremity scanning, etc. With its vast spectrum of applications in the health care system, the future of low-field pMRI units seems to be bright.
Nonlinear interaction of two non-uniform vortex sheets and large vorticity amplification in Richtmyer–Meshkov instability
Authors: Matsuoka Chihiro , Nishihara Katsunobu
Published: June 2023

Vortex dynamics is an important research subject for geophysics, astrophysics, engineering, and plasma physics. Regarding vortex interactions, only limited problems, such as point vortex interactions, have been studied. Here, the nonlinear interaction of two non-uniform vortex sheets with density stratification is investigated using the vortex sheet model. These non-uniform vortex sheets appear, for example, in the Richtmyer–Meshkov instability that occurs when a shock wave crosses a layer with two corrugated interfaces. When a strong vortex sheet approaches a weaker vortex sheet with opposite-signed vorticity, a locally peaked secondary vorticity is induced on the latter sheet. This emerging secondary vorticity results in a remarkable vorticity amplification on the stronger sheet, and a strong vortex core is formed involving the weak vortex sheet. The amplified vortices with opposite signs on the two vortex sheets form pseudo-vortex pairs, which cause an intense rolling-up of the two sheets. We also investigated the dependence of distance and initial phase difference of vorticity perturbations between two vortex sheets on the vorticity amplification and vortex sheet dynamics.
Low-frequency noise in quasi-ballistic monolithic Al–Ge–Al nanowire field effect transistors
Authors: Behrle R. , Sistani M. , Lugstein A. , Sadre Momtaz Z. , den Hertog M. I. , Pogany D. , Weber W. M.
Published: June 2023

In this work, Al2O3-passivated, monolithic, and crystalline Al–Ge–Al heterostructure nanowire field effect transistors (FETs) with Ge channel lengths ranging from 18 to 826 nm are analyzed from a low-frequency noise perspective. 1/f and random telegraph noise (RTN) are analyzed in an accumulation mode, where the hole channel is formed by applying a back-gate potential VG. The normalized power spectral density of drain current fluctuations of 1/f noise (SID/ID2) at medium currents follows nearly an 1/ID trend. 1/f noise is analyzed within both the mobility and carrier number fluctuation models (MFM and CNFM), respectively. Taking the MFM into account, the Hooge noise parameter α spreads in the interval of 1.5 × 10−4 to 4 × 10−2, with lower values for shorter devices. Using the same data and the CNFM, the density of interface states Dit in the Al2O3/GexOy/Ge system was estimated using the transconductance extracted from the quasi-static transfer I/V characteristics. The extracted Dit values range from 5 × 109 to 3 × 1012 cm−2 eV−1. Contact noise has also been observed in some devices at high currents. RTN analyzed in time domain exhibits a relative RTN amplitude in the 0.3%–20% range. Capture and emission time constants as a function of VG exhibit a typical behavior for metal oxide semiconductor FETs. The extracted noise parameters are comparable with Ge and III–V nanodevices of top-down and bottom-up technologies.
Ethanol–water motifs—A re-interpretation of the double-difference pair distribution functions of aqueous iron oxide nanoparticle dispersions
Authors: Thomä Sabrina L. J. , Zobel Mirijam
Published: June 2023

In dispersion, nanoparticles can interact with the surrounding dispersion medium, such that an interfacial region with a structure differing from that of the bulk exists. Distinct nanoparticulate surfaces induce specific degrees of interfacial phenomena, and the availability of surface atoms is a crucial prerequisite for interfacial restructuring. Here, we investigate the nanoparticle–water interface of 0.5–10 wt. % aqueous iron oxide nanoparticle dispersions of 6 nm diameter in the presence of 6 vol. % ethanol with x-ray absorption spectroscopy (XAS) and atomic pair distribution function (PDF) analysis. The absence of surface hydroxyl-groups in XAS spectra is in accordance with the double-difference PDF (dd-PDF) analysis, due to a fully covered surface from the capping agent. The previously observed dd-PDF signal is not stemming from a hydration shell, as postulated in Thomä et al. [Nat Commun. 10, 995 (2019)], but from the residual traces of ethanol from nanoparticle purification. With this article, we provide an insight into the arrangement of EtOH solutes in water at low concentration.
Theoretical study of the impact of alloy disorder on carrier transport and recombination processes in deep UV (Al,Ga)N light emitters
Authors: Finn R. , O'Donovan M. , Farrell P. , Moatti J. , Streckenbach T. , Koprucki T. , Schulz S.
Published: June 2023

Aluminum gallium nitride [(Al,Ga)N] has gained significant attention in recent years due to its potential for highly efficient light emitters operating in the deep ultra-violet (UV) range (<280 nm). However, given that current devices exhibit extremely low efficiencies, understanding the fundamental properties of (Al,Ga)N-based systems is of key importance. Here, using a multi-scale simulation framework, we study the impact of alloy disorder on carrier transport, radiative and non-radiative recombination processes in a c-plane Al0.7Ga0.3N/Al0.8Ga0.2N quantum well embedded in a p–n junction. Our calculations reveal that alloy fluctuations can open “percolative” pathways that promote transport for the electrons and holes into the quantum well region. Such an effect is neglected in conventional and widely used transport simulations. Moreover, we find that the resulting increased carrier density and alloy induced carrier localization effects significantly increase non-radiative Auger–Meitner recombination in comparison to the radiative process. Thus, to suppress such non-radiative process and potentially related material degradation, a careful design (wider well, multi-quantum wells) of the active region is required to improve the efficiency of deep UV light emitters.
Ultralight and sensitive ferroelectret films with a human skin-like texture
Authors: Ruan Zehai , Hu Qianqian , Zhang Mi , Liu Weilin , Zhu Guodong , Chen Min , Zhang Xiaoqing
Published: June 2023

Biologically inspired by natural skin, polypropylene (PP) ferroelectret films with a human skin-like texture, featuring lightweight, light transmittance, small thickness, stretchability, as well as significant longitudinal and transverse piezoelectric activity, are prepared with a simple procedure, and their piezoelectric properties are characterized. The mechanical structure of the fabricated ferroelectret films is of a double-level cellular structure with distributed tight junctions and dipolar charges deposited on the opposite inner walls of cells. The preliminary results show that the area density, light transmittance, and thickness of the films are 3.5 g/m2, 80%, and 10–20 μm, respectively. A quasi-static piezoelectric d33 coefficient of a few thousand pC/N at 3.4 kPa and a dynamic piezoelectric d31 coefficient of −40 pC/N at a frequency of 80 Hz and a stress of 20 kPa are achieved. The improved piezoelectric performance seems mainly owing to the reduction of the elastic modulus for the double-level structure and the enhancement of charges in deep traps in very thin cell walls. The sound pressure level, generated by an ultrasonic emitter made of the PP ferroelectret film, is about 87 dB at 46 kHz as driven by a voltage of 20 V (peak to peak voltage). An ultra-thin tactile sensor based on the fabricated films can localize positions and detect the track and moving speed of applied force. These results indicate that the cost-efficient films may extend the applications of ferroelectrets in flexible electronics.
Quantitative morphological analysis of InP-based quantum dots reveals new insights into the complexity of shell growth
Authors: Click Sophia M. , Koziel Alexandra C. , Torres Ruben , Flores Sebastian , McBride James R. , Rosenthal Sandra J.
Published: June 2023

The incorporation of quantum dots in display technology has fueled a renewed interest in InP-based quantum dots, but difficulty controlling the Zn chemistry during shelling has stymied thick, even ZnSe shell growth. The characteristic uneven, lobed morphology of Zn-based shells is difficult to assess qualitatively and measure through traditional methods. Here, we present a methodological study utilizing quantitative morphological analysis of InP/ZnSe quantum dots to analyze the impact of key shelling parameters on InP core passivation and shell epitaxy. We compare conventional hand-drawn measurements with an open-source semi-automated protocol to showcase the improved precision and speed of this method. Additionally, we find that quantitative morphological assessment can discern morphological trends in morphologies that qualitative methods cannot. In conjunction with ensemble fluorescence measurements, we find that changes to shelling parameters that promote even shell growth often do so at the cost of core homogeneity. These results indicate that the chemistry of passivating the core and promoting shell growth must be balanced carefully to maximize brightness while maintaining emission color-purity.
A control method for acoustic radiation force of ultrahigh frequency ultrasound based on variable frequency pulse width modulation
Authors: Wu Jinzhe , Shi Jialin , Li Zhaoxi , Yu Peng , Shi Huiyao , Yang Tie , Yang Yang , Fei Chunlong , Liu Lianqing
Published: June 2023

Ultrahigh frequency ultrasound (>60 MHz) has emerged as a crucial actuating mechanism for non-contact manipulation, owing to its unique acoustic field properties. The acoustic field traps microparticles mainly via the gradient force of acoustic radiation force (ARF) on the transverse plane, which is up to hundreds of nanonewtons. In theory, directly using ARF can strengthen the manipulation force. Currently, the direct implementation of ARF is restricted to a specific frequency and magnitude range, which lacks a comprehensive and versatile control method. Additionally, it lacks an ARF calibration method that accommodates a wide magnitude and frequency range. We propose a variable frequency pulse width modulation-based control method for ARF, which uses an atomic force microscope microcantilever as a mechanical sensor to calibrate the magnitude and frequency. The precise control of ARF emitted by an 85 MHz transducer was achieved with a resolution of hundreds of piconewtons, magnitude range spanning from nanonewtons to micronewtons, and frequency range of 1 kHz to hundreds of kilohertz. This control method breakthrough holds great promise for expanding the application of ultrahigh frequency ultrasound in noncontact manipulation.
Formation of the C4Hn+ (n = 2–5) ions upon ionization of acetylene clusters in helium droplets
Authors: Moon Cheol Joo , Erukala Swetha , Feinberg Alexandra J. , Singh Amandeep , Choi Myong Yong , Vilesov Andrey F.
Published: June 2023

Infrared (IR) spectroscopy using ultracold helium nanodroplet matrices has proven to be a powerful method to interrogate encapsulated ions, molecules, and clusters. Due to the helium droplets’ high ionization potential, optical transparency, and ability to pick up dopant molecules, the droplets offer a unique modality to probe transient chemical species produced via photo- or electron impact ionization. In this work, helium droplets were doped with acetylene molecules and ionized via electron impact. Ion-molecule reactions within the droplet volume yield larger carbo-cations that were studied via IR laser spectroscopy. This work is focused on cations containing four carbon atoms. The spectra of C4H2+, C4H3+, and C4H5+ are dominated by diacetylene, vinylacetylene, and methylcyclopropene cations, respectively, which are the lowest energy isomers. On the other hand, the spectrum of C4H4+ ions hints at the presence of several co-existing isomers, the identity of which remains to be elucidated.
A three-dimensional fictitious domain method for direct numerical simulations of particle-laden flows with heat transfer
Authors: Fan Peifei , Lin Zhaowu , Xu Jian , Yu Zhaosheng
Published: June 2023

In the present work, a three-dimensional fictitious domain method for particulate flows with heat transfer is proposed. For the case of fixed particle temperature, an iterative scheme for the temperature Lagrange multiplier is proposed, in order to determine its initial value and overcome the spurious oscillation of the explicit scheme at the initial time stage for different initial fluid and particle temperatures. Both explicit and implicit schemes are proposed for the solution of coupled fluid and solid temperature equations in the case of freely evolving particle temperature. The implicit scheme is suited to the case of large density ratios, specific heat ratios, or thermal conductivity ratios. Our method for the case of fixed particle temperature is verified via the test problems of a stationary hot sphere heating the surrounding quiescent fluid, a fixed sphere, and spheroid, respectively, in uniform flow, and sedimentation of a sphere and spheroid, respectively, in a vertical channel. We propose a new correlation of particle Nusselt number for an isolated sphere in a relatively small domain. Our code for the case of varying particle temperatures is verified via the effective thermal conductivity of a motionless sphere and the rising of a catalyst particle in an enclosure. Our method is applied to the sedimentation of a sphere at different Grashof numbers, specific heat ratios, and conductivity ratios. In addition, some preliminary results on heat transfer in turbulent channel flows laden with neutrally buoyant spherical and spheroidal particles, respectively, from fully resolved simulations with our method are reported.
Non-linear physical aging of supercooled glycerol induced by large upward ideal temperature steps monitored through cooling experiments
Authors: Hénot Marceau , Ladieu François
Published: June 2023

The physical aging of supercooled glycerol induced by upward temperature steps of amplitude reaching 45 K was studied by a new method consisting in heating a micrometer-thick liquid film at a rate of up to 60 000 K/s, holding it at a constant high temperature for a controlled duration before letting it quickly cool down to the initial temperature. By monitoring the final slow relaxation of the dielectric loss, we were able to obtain quantitative information on the liquid response to the initial upward step. The so-called TNM (Tool–Narayanaswamy–Moynihan) formalism provided a good description of our observations despite the large distance from equilibrium, provided that different values of the nonlinearity parameter were used for the cooling phase and for the (much further from equilibrium) heating phase. In this form, it allowed to precisely quantify how to design an ideal temperature step, i.e., where no relaxation occurs during the heating phase. It helped bringing a clear physical understanding of how the (kilosecond long) final relaxation is related to the (millisecond long) liquid response to the upward step. Finally, it made possible the reconstruction of the fictive temperature evolution immediately following a step, evidencing the highly non-linear character of the liquid response to such large amplitude temperature steps. This work illustrates both the strengths and limitations of the TNM approach. This new experimental device offers a promising tool to study far-from-equilibrium supercooled liquids through their dielectric response.
Effect of electric field on mass transfer during oleuropein extraction
Authors: Cokgezme Omer Faruk , Icier Filiz
Published: June 2023

The use of alternative extraction methods has increased since conventional methods have disadvantages like long processing time and limited extraction yield. It is known that the extraction yield is enhanced, and the processing time is shortened by the electric field. However, the mathematical characterization of the electrically assisted processes is needed for a better understanding and the improvement of extraction. In this study, effects of the moderate electric field extraction (MEF-E) parameters (frequencies of 1, 1000, and 2000 Hz, and wave types of sine and square) on yield, cell disintegration index (Zc), microstructure, and mass transfer coefficient (Deff) were investigated to examine mass transfer characteristics of the extraction of oleuropein from olive leaves. Correlation analysis was performed to investigate the relations between yield, Zc, Deff, and the changes in the cross section areas of palisade cells. The frequency and wave significantly affected yield, Zc, microstructural changes, and Deff values (p < 0.05). Additionally, the Zc value showed a good correlation with yield, microstructure, and Deff in both sine and square waves (p < 0.05). It was concluded that the extraction level and microstructural changes could be controlled by Zc during the MEF-E process. Two different finite element models (model 1: fixed Deff and model 2: Deff depending on the Zc) were used for mass transfer, and model 2 gave better predictions (p < 0.05). Thus, it will be possible to characterize and monitor oleuropein transfer depending on the effects of frequency and wave type applications during the MEF process. The model consisting of the Zc–Deff relationship showed that the use of Zc would be preferred for the characterization of mass transfer rather than calculating the Deff value. It is thought that the effects of electric field parameters on microstructure with the developed models will be determined and successfully characterized, thus contributing to the understanding of the effects of electric field extraction processes on mass transfer. However, it is recommended that similar studies are conducted for other plants in order to develop a valid approach on the extraction process from plants.
A [3]-catenane non-autonomous molecular motor model: Geometric phase, no-pumping theorem, and energy transduction
Authors: Bilancioni Massimo , Esposito Massimiliano , Penocchio Emanuele
Published: June 2023

We study a model of a synthetic molecular motor—a [3]-catenane consisting of two small macrocycles mechanically interlocked with a bigger one—subjected to time-dependent driving using stochastic thermodynamics. The model presents nontrivial features due to the two interacting small macrocycles but is simple enough to be treated analytically in limiting regimes. Among the results obtained, we find a mapping into an equivalent [2]-catenane that reveals the implications of the no-pumping theorem stating that to generate net motion of the small macrocycles, both energies and barriers need to change. In the adiabatic limit (slow driving), we fully characterize the motor’s dynamics and show that the net motion of the small macrocycles is expressed as a surface integral in parameter space, which corrects previous erroneous results. We also analyze the performance of the motor subjected to step-wise driving protocols in the absence and presence of an applied load. Optimization strategies for generating large currents and maximizing free energy transduction are proposed. This simple model provides interesting clues into the working principles of non-autonomous molecular motors and their optimization.
Unsteady flow enhancement on an airfoil using sliding window weak-constraint four-dimensional variational data assimilation
Authors: Li Sen , He Chuangxin , Liu Yingzheng
Published: June 2023

This study establishes a continuous sliding window weak-constraint four-dimensional variational approach for reproducing a complete instantaneous flow from sparse spatiotemporal velocity observations. The initial condition, boundary condition, and model-form uncertainties are corrected simultaneously by a spatiotemporally varying additive forcing, coupled with the large eddy simulation (LES) framework, which reinforces subgrid-scale viscosity stresses and simplifies gradient computation. The additive force undergoes a Stokes–Helmholtz decomposition to ensure divergence-free projection and natural pressure determination. The model is theoretically derived to minimize discrepancies between the sparse velocity observations and the numerical predictions of the primary-adjoint system, enabling optimal contribution of the additive force. Synthetic data from a fine-grid LES of the vortical flow over an NACA0012 airfoil are used as observations. The algorithm is evaluated on a benchmark case, where observations are subsampled at 1/400 000 spatiotemporal resolution required for an LES. The sliding window strategy expands the dependence domain of the observations and mitigates the impact of primary-adjoint chaos, achieving over 90% pointwise correlation for filtered parameters and 80% spectral correlation for all of the resolved wavenumbers. Despite the lack of near-wall observations, streaks are accurately recovered due to the convective sensitivity of the observations from the outer flow. While the pressure fluctuation in the inflow region is not as well excited as in LES, recovery is augmented downstream. In both the inner and outer wall layers, the pressure distributions are obtained reasonably well by capturing the signatures of the vortical structure and their downstream convection. The robustness of the algorithm to observation noise is demonstrated. Finally, the impact of temporal resolution on estimation is evaluated, establishing a resolution threshold for successful reconstruction.
Affable thermal treatment process to overcome the trade-off relation via interface engineering in an Fe-based amorphous film
Authors: Peng X. J. , Lu Z. , Bai H. Y.
Published: June 2023

As pre-eminent soft magnetic materials, Fe-based amorphous alloys have been extensively studied due to adjustable composition, low cost, and low iron core loss. The soft magnetic properties could be further improved after thermal annealing, which achieve a low coercive force (Hc) due to the low magnetic anisotropy and a high saturation magnetic flux density (Bs) on account of the precipitation of soft magnetic nanocrystalline phases. However, it is a key difficulty to control the nucleation and growth procedures of nanocrystals during annealing, resulting in rapid deterioration of Hc. Here, a soft magnetic Fe76Si8B13Nb3 film with ultra-fine amorphous/crystalline (a/c) core–shell structure is achieved from an amorphous precursor with the nanoscale phase separation. The pre-existing nanoscale phase separation provides vast nucleation sites and interphase boundaries, which could generate high concentration of nanocrystals and depresses the subsequent coarsening behavior even for long-time heat treatment. In consequence, the a/c core–shell soft magnetic film breaks the general trade-off relation in the soft magnetic material family with the highest Bs and lowest Hc simultaneously. This work provides a new perspective to design a/c alloys by amorphous precursor with dual phase structure, and importantly, it supplies effortless thermal treatment requirement to conveniently regulate the microstructures and soft magnetic properties of metallic glasses.
Broadband control of flow of light using plasmonic metasurfaces consisting of arrays of metallic split ring nanoantennas
Authors: Sadeghi Seyed M. , Roberts Dustin T. , Knox Harrison , Gutha Rithvik R.
Published: June 2023

When a metallic U-shaped nanoantenna (split ring resonator) is observed from its sides, variations in the viewing angle can lead to significantly different size and shape projections. In this study, we demonstrate that plasmonic metasurfaces consisting of arrays of such nanoantennas can support unique side (in-plane) scattering switching and routing processes. These processes encompass a polarization switching centered at 1.6 μm, which is driven by the coherent excitation of the nanoantennas’ multipolar modes. They also include spectrally broadband (0.5–1.6 μm) directional control of the flow of in-plane light scattering. Such a process includes a total prohibition of light emerging from one side of the metasurface for a given polarization of the incident light. However, when such polarization is rotated by 90°, the flow of the in-plane scattering opens with high efficiency. We further discuss the impact of the formation of surface lattice resonance on the coherent amplification of infrared scattering around 1.6 μm and its switching process. The results underscore the influence of variations in asymmetry, associated with the sizes and shape projections, on interference processes. They also showcase how in-plane scattering has the capacity to transfer distinct characteristics of plasmonic near-field asymmetries induced by optical fields into far-field scattering.
Machine-learned constitutive relations for multi-scale simulations of well-entangled polymer melts
Authors: Molina John J.
Published: June 2023

We investigate the use of a machine-learning-based simulation scheme to predict flows of complex fluids with a non-linear constitutive relation. This scheme, originally proposed by Seryo et al. for general complex fluids [N. Seryo et al., “Learning the constitutive relation of polymeric flows with memory,” Phys. Rev. Res. 2, 033107 (2020)], is used to learn the time derivative of the stress as a function of the stress and velocity gradient. However, previous assessments were limited to fluids with linear constitutive relations. In this study, we employ the dual sliplink model to express the dynamics of well-entangled polymers as a fluid exhibiting a non-linear stress response. We test the simulation scheme by using it to predict the flow of a viscoelastic fluid between two parallel plates with only shear deformations and compare the results with those of a multi-scale simulation using microscopic simulators. Overall, our machine-learning method possesses good predictive capabilities, for both the transient response and the non-linear behavior at steady-state, i.e., the shear-thinning. We are able to accurately track the evolution of the stress, for both the weak and strong elastic cases, although the velocity predictions for the latter show a decreased accuracy in the transient regime. Furthermore, our simulation scheme is more computationally efficient than the conventional multi-scale simulation approach, which uses microscopic simulators, containing a system of coarse-grained polymers, to evaluate the macroscopic stress. We discuss possible extensions and improvements for enhancing the predictive capabilities and generality of the method.
The evolution of early hominin food production and sharing
Authors: Alger Ingela , Dridi Slimane , Stieglitz Jonathan , Wilson Michael L.
Published: June 2023

How did humans evolve from individualistic to collective foraging with sex differences in production and widespread sharing of plant and animal foods? While current evolutionary scenarios focus on meat, cooking, or grandparental subsidies, considerations of the economics of foraging for extracted plant foods (e.g., roots, tubers), inferred to be important for early hominins (∼6 to 2.5 mya), suggest that early hominins shared such foods with offspring and others. Here, we present a conceptual and mathematical model of early hominin food production and sharing, prior to the emergence of frequent hunting, cooking, and increased lifespan. We hypothesize that extracted plant foods were vulnerable to theft, and that male mate guarding protected females from food theft. We identify conditions favoring extractive foraging and food sharing across mating systems (i.e., monogamy, polygyny, promiscuity), and we assess which system maximizes female fitness with changes in the profitability of extractive foraging. Females extract foods and share them with males only when: i) extracting rather than collecting plant foods pays off energetically; and ii) males guard females. Males extract foods when they are sufficiently high in value, but share with females only under promiscuous mating and/or no mate guarding. These results suggest that if early hominins had mating systems with pair-bonds (monogamous or polygynous), then food sharing by adult females with unrelated adult males occurred before hunting, cooking, and extensive grandparenting. Such cooperation may have enabled early hominins to expand into more open, seasonal habitats, and provided a foundation for the subsequent evolution of human life histories.
Universal open MHC-I molecules for rapid peptide loading and enhanced complex stability across HLA allotypes
Authors: Sun Yi , Young Michael C. , Woodward Claire H. , Danon Julia N. , Truong Hau V. , Gupta Sagar , Winters Trenton J. , Font-Burgada Joan , Burslem George M. , Sgourakis Nikolaos G.
Published: June 2023

The polymorphic nature and intrinsic instability of class I major histocompatibility complex (MHC-I) and MHC-like molecules loaded with suboptimal peptides, metabolites, or glycolipids presents a fundamental challenge for identifying disease-relevant antigens and antigen-specific T cell receptors (TCRs), hindering the development of autologous therapeutics. Here, we leverage the positive allosteric coupling between the peptide and light chain (β
2
microglobulin, β
2
m) subunits for binding to the MHC-I heavy chain (HC) through an engineered disulfide bond bridging conserved epitopes across the HC/β
2
m interface, to generate conformationally stable, peptide-receptive molecules named “open MHC-I.” Biophysical characterization shows that open MHC-I molecules are properly folded protein complexes of enhanced thermal stability compared to the wild type when loaded with low- to moderate-affinity peptides. Using solution NMR, we characterize the effects of the disulfide bond on the conformation and dynamics of the MHC-I structure, ranging from local changes in β
2
m-interacting sites of the peptide-binding groove to long-range effects on the α
2-1
helix and α
3
domain. The interchain disulfide bond stabilizes MHC-I molecules in an open conformation to promote peptide exchange across multiple human leukocyte antigen (HLA) allotypes, covering representatives from five HLA-A supertypes, six HLA-B supertypes, and oligomorphic HLA-Ib molecules. Our structure-guided design, combined with conditional β-peptide ligands, provides a universal platform to generate ready-to-load MHC-I systems of enhanced stability, enabling a range of approaches to screen antigenic epitope libraries and probe polyclonal TCR repertoires covering highly polymorphic HLA-I allotypes, as well as oligomorphic nonclassical molecules.
Effective laser treatment in a case of lupus pernio
Authors: Ekbäck M , Molin L.
Published: June 2023

No abstract available
Localized multiple pseudoatrophic plaques: a rare clinical form of segmental neurofibromatosis
Authors: Misago N , Narisawa Y.
Published: June 2023

No abstract available
Bullous pemphigoid on psoriasis lesions after UVA radiation
Authors: Washio H , Hara H , Suzuki H , Yoshida M , Hashimoto T.
Published: June 2023

No abstract available
Keratosis lichenoides chronica: marked response to PUVA in combination with acitretin
Authors: Demirci E , Boyvat A , Arica IE , Kocyigit P , Ozdemir E , Heper AO.
Published: June 2023

No abstract available
Acta Dermato-Venereologica becomes its own publisher and moves towards open access
Authors: Bäck O , Vahlquist A , Andersson A.
Published: June 2023

No abstract available
Reflecting boundary conditions in numerical relativity as a model for black hole echoes
Authors: Dailey Conner , Afshordi Niayesh , Schnetter Erik
Published: June 2023

Recently, there has been much interest in black hole echoes, based on the idea that there may be some mechanism (e.g. from quantum gravity) that waves/fields falling into a black hole could partially reflect off of an interface before reaching the horizon. There does not seem to be a good understanding of how to properly model a reflecting surface in numerical relativity, as the vast majority of the literature avoids the implementation of artificial boundaries, or applies transmitting boundary conditions. Here, we present a framework for reflecting a scalar field in a fully dynamical spherically symmetric spacetime, and implement it numerically. We study the evolution of a wave packet in this situation and its numerical convergence, including when the location of a reflecting boundary is very close to the horizon of a black hole. This opens the door to model exotic near-horizon physics within full numerical relativity.
Traversable wormholes in four dimensions
Authors: Maldacena Juan , Milekhin Alexey , Popov Fedor
Published: June 2023

We present a wormhole solution in four dimensions. It is a solution of an Einstein Maxwell theory plus charged massless fermions. The fermions give rise to a negative Casimir-like energy, which makes the wormhole possible. It is a long wormhole that does not lead to causality violations in the ambient space. It can be viewed as a pair of entangled near extremal black holes with an interaction term generated by the exchange of fermion fields. The solution can be embedded in the Standard Model by making its overall size small compared to the electroweak scale.
Interfacial rheology insights: particle texture and Pickering foam stability
Authors: Brown Nick , de la Pena Alec , Razavi Sepideh
Published: June 2023

Interfacial rheology studies were conducted to establish a connection between the rheological characteristics of particle-laden interfaces and the stability of Pickering foams. The behavior of foams stabilized with fumed and spherical colloidal silica particles was investigated, focusing on foam properties such as bubble microstructure and liquid content. Compared to a sodium dodecyl sulfate-stabilized foam, Pickering foams exhibited a notable reduction in bubble coarsening. Drop shape tensiometry measurements on particle-coated interfaces indicated that the Gibbs stability criterion was satisfied for both particle types at various surface coverages, supporting the observed arrested bubble coarsening in particle-stabilized foams. However, although the overall foam height was similar for both particle types, foams stabilized with fumed silica particles demonstrated a higher resistance to liquid drainage. This difference was attributed to the higher yield strain of interfacial networks formed by fumed silica particles, as compared to those formed by spherical colloidal particles at similar surface pressures. Our findings highlight that while both particles can generate long-lasting foams, the resulting Pickering foams may exhibit variations in microstructure, liquid content, and resistance to destabilization mechanisms, stemming from the respective interfacial rheological properties in each case.