bluuebunny/crossref_metadata_2025 huggingface dataset:
Individuals with psychosis receive less electric field strength during transcranial direct current stimulation compared to healthy controls
Authors: Kazinka Rebecca , Choi Da Som , Opitz Alexander , Lim Kelvin O.
Published: November 2024

Recent research has examined the effectiveness of transcranial direct current stimulation (tDCS) as an adjunctive treatment for antipsychotics, finding mixed results on cognitive, positive, and negative symptoms. We tested if individuals with psychosis have reduced electric field strength compared to healthy controls and assessed the potential causal factors. We hypothesized that either cortical thinning due to the disorder or increased scalp thickness due to secondary effects of the disorder were causal factors. Using the Psychosis Human Connectome Project dataset, we simulated electric field models for 136 individuals with psychosis, 73 first-degree relatives, and 43 healthy controls. We compared group differences of electric field strength at bilateral dorsolateral prefrontal cortex (dlPFC), targeted with two montages (Fp1-Fp2 & F3-Fp2) commonly used to treat cognitive impairment. We additionally compared groups on scalp, skull, and cerebrospinal fluid thickness at bilateral dlPFC and the three electrode locations. Mediation analyses assessed if tissue thickness and BMI were causal factors for group differences while controlling for age and sex. Individuals with psychosis had lower electric field strength for bilateral dlPFC for both montages. Scalp thickness was also greater for individuals with psychosis, but cerebrospinal fluid thickness was not significantly different. BMI was a significant mediator for the group difference seen in both scalp thickness and electric field strength. Future treatment studies using tDCS in the psychosis population should include electric field modeling to assess its effectiveness given the increased risk of obesity. Individualized montages based on head models may also improve effectiveness.
MTBVAC induces superior antibody titers and IgG avidity compared to BCG vaccination in non-human primates
Authors: Peralta-Álvarez Marco Polo , Downward Keya , White Andrew , Redondo Azema Hugo , Sibley Laura , Sarfas Charlotte , Morrison Alexandra , Dennis Mike , Diaz-Santana Delia , Harris Stephanie A. , Li Shuailin , Puentes Eugenia , Aguilo Nacho , Martin Carlos , Sharpe Sally , McShane Helen , Tanner Rachel
Published: November 2024

The only currently licensed vaccine against tuberculosis (TB), Bacille Calmette Guérin (BCG), is insufficient to control the epidemic. MTBVAC is a live attenuated strain of Mycobacterium tuberculosis (M.tb) and is one the most advanced TB vaccine candidates in the pipeline. It is more efficacious than BCG in preclinical models including non-human primates (NHPs), and has demonstrated safety and immunogenicity in human populations. To better understand the immune mechanisms underlying the superior efficacy conferred by MTBVAC, we characterized M.tb-specific antibody responses in NHPs vaccinated with either BCG or MTBVAC. MTBVAC vaccination induced higher titers of IgG, IgM and IgA, and higher avidity IgG compared with BCG vaccination. IgG avidity correlated with protection following M.tb challenge in the same animals, validating the association previously reported between this measure and protection in the context of intravenous BCG vaccination, suggesting that IgG avidity may represent a relevant marker or correlate of protection from TB.
Preclinical characterization of the Omicron XBB.1.5-adapted BNT162b2 COVID-19 vaccine
Authors: Modjarrad Kayvon , Che Ye , Chen Wei , Wu Huixian , Cadima Carla I. , Muik Alexander , Maddur Mohan S. , Tompkins Kristin R. , Martinez Lyndsey T. , Cai Hui , Ramos Minah , Mensah Sonia , Cumbia Brittney , Falcao Larissa , McKeen Andrew P. , Chang Jeanne S. , Fennell Kimberly F. , Huynh Kevin W. , McLellan Thomas J. , Sahasrabudhe Parag V. , Chen Wei , Cerswell Michael , Garcia Miguel A. , Li Shilong , Sharma Rahul , Li Weiqiang , Dizon Kristianne P. , Duarte Stacy , Gillett Frank , Smith Rachel , Illenberger Deanne M. , Efferen Kari Sweeney , Vogel Annette B. , Anderson Annaliesa S. , Şahin Uğur , Swanson Kena A.
Published: November 2024

As SARS-CoV-2 evolves, increasing in potential for greater transmissibility and immune escape, updated vaccines are needed to boost adaptive immunity to protect against COVID-19 caused by circulating strains. Here, we report features of the monovalent Omicron XBB.1.5-adapted BNT162b2 vaccine, which contains XBB.1.5-specific sequence changes, relative to the original BNT162b2 backbone, in the encoded prefusion-stabilized SARS-CoV-2 spike protein (S(P2)). Biophysical characterization of Omicron XBB.1.5 S(P2) demonstrated that it maintains a prefusion conformation and adopts a flexible, predominantly open, state, with high affinity for the human ACE-2 receptor. When administered as a 4th dose in BNT162b2-experienced mice, the monovalent Omicron XBB.1.5 vaccine elicited substantially higher serum neutralizing titers against pseudotyped viruses of Omicron XBB.1.5, XBB.1.16, XBB.1.16.1, XBB.2.3, EG.5.1 and HV.1 sublineages and phylogenetically distant BA.2.86 lineage than the bivalent Wild Type + Omicron BA.4/5 vaccine. Similar trends were observed against Omicron XBB sublineage pseudoviruses when the vaccine was administered as a 2-dose series in naive mice. Strong S-specific Th1 CD4+ and IFNγ+ CD8+ T cell responses were also observed. These findings, together with real world performance of the XBB.1.5-adapted vaccine, suggest that preclinical data for the monovalent Omicron XBB.1.5-adapted BNT162b2 was predictive of protective immunity against dominant SARS-CoV-2 strains.
Nitrogen isotopes reveal high NOx emissions from arid agricultural soils in the Salton Sea Air Basin
Authors: Lieb Heather C. , Maldonado Matthew , Ruiz Edgar , Torres Christian , Olmedo Luis , Walters Wendell W. , Faloona Ian C.
Published: November 2024

Air quality management commonly aims to mitigate nitrogen oxide (NOx) emissions from combustion, reducing ozone (O3) and particulate matter (PM) pollution. Despite such ongoing efforts, regulations have recently proven ineffective in rural areas like the Salton Sea Air Basin of Southern California, which routinely violates O3 and PM air quality standards. With over $2 billion in annual agricultural sales and low population density, air quality in the region is likely influenced by the year-round farming activity. We conducted a source apportionment of NOx (an important precursor to both O3 and PM) using nitrogen stable isotopes of ambient NO2, which revealed a significant contribution from soil-emitted NOx to the regional budget. The soil source strength was estimated based on the mean δ15N-NOx from each emission category in the California Air Resources Board’s NOx inventory. Our annual average soil emission estimate for the air basin was 11.4 ± 4 tons/d, representing ~ 30% of the extant NOx inventory, 10× larger than the state’s inventory for soil emissions. Unconstrained environmental factors such as nutrient availability, soil moisture, and temperature have a first-order impact on soil NOx production in this agriculturally intensive region, with fertilization and irrigation practices likely driving most of the emissions variability. Without spatially and temporally accurate data on fertilizer application rates and irrigation schedules, it is difficult to determine the direct impacts that these variations have on our observations. Nevertheless, comparative analysis with previous studies indicates that soil NOx emissions in the Imperial Valley are likely underrepresented in current inventories, highlighting the need for more detailed and localized observational data to constrain the sizeable and variable emissions from these arid, agricultural soils.
Spatiotemporal changes in riverine input into the Eocene North Sea revealed by strontium isotope and barium analysis of bivalve shells
Authors: Kniest Jorit F. , Evans David , Gerdes Axel , Cantine Marjorie , Todd Jonathan A. , Sigwart Julia D. , Vellekoop Johan , Müller Wolfgang , Voigt Silke , Raddatz Jacek
Published: November 2024

Reconstructing hydrological conditions of past warm periods, such as the Eocene ‘hot house’ provides empirical data to compare to state of the art climate models. However, reconstructing these changes in deep time is challenging, for example, given the complex interplay between evapotranspiration, precipitation and runoff. As a proxy for past changes in these hydrological systems, the dynamics of fresh water input into marginal seas can be used to identify the spatiotemporal distribution of riverine runoff. Elemental barium (Ba) and radiogenic strontium (87Sr) are, depending on the amount of runoff and the background geology of the catchment area, typically enriched in river waters in comparison to seawater and can thus be utilized to determine changes in riverine fresh water discharge. Here, we use barium to calcium ratios (Ba/Ca) and radiogenic strontium isotopes (87Sr/86Sr) measured in fossil bivalve shells to reconstruct patterns of fresh water input into the paleo North Sea during the early to middle Eocene. Our reconstruction shows the potential of Ba/Ca and87Sr/86Sr to serve as proxies for riverine runoff and highlights the spatiotemporal complexity of Eocene hydrological conditions in western Europe. In particular, our results enable changes in riverine input along geological to perennial time scales for different coastal regions to be determined, revealing a steady influx of fresh water, but with distinct spatiotemporal differences.
Impaired noise adaptation contributes to speech intelligibility problems in people with hearing loss
Authors: Marrufo-Pérez Miriam I. , Fumero Milagros J. , Eustaquio-Martín Almudena , Lopez-Poveda Enrique A.
Published: November 2024

Understanding speech in noisy settings is harder for hearing-impaired (HI) people than for normal-hearing (NH) people, even when speech is audible. This is often attributed to hearing loss altering the neural encoding of temporal and/or spectral speech cues. Here, we investigated whether this difference may also be due to an impaired ability to adapt to background noise. For 25 adult hearing-aid users with sensorineural hearing loss, speech reception thresholds (SRTs) were measured for natural and tone-vocoded words embedded in speech-shaped noise (SSN). The stimuli were preceded or not by a 1-second adapting SSN precursor. Adaptation was calculated as the difference in SRT between the two precursor conditions. Corresponding data for 28 NH listeners were taken from a previously published study. SRTs were worse for HI listeners, confirming that hearing loss diminishes access to speech acoustic cues. Furthermore, noise adaptation was negatively correlated with the age-controlled hearing loss both for natural (rho=-0.56, N = 52, p < 0.001) and vocoded (rho=-0.45, N = 39, p = 0.002) words. Impaired adaptation contributed up to 10% of the SRT loss in HI listeners. We conclude that HI listeners suffer from poorer speech in noise recognition not only because of impaired access to speech acoustic cues but also because they are less able to adapt to background noise.
Role of Hog1-mediated stress tolerance in biofilm formation by the pathogenic fungus Trichosporon asahii
Authors: Matsumoto Yasuhiko , Nakayama Mei , Shimizu Yuta , Koganesawa Sachi , Kanai Hiromi , Sugiyama Yu , Kurakado Sanae , Sugita Takashi
Published: November 2024

Trichosporon asahii, a dimorphic fungus, causes bloodstream infections in immunocompromised patients with neutropenia. Biofilms are formed on the surfaces of medical devices such as catheters as T. asahii transitions morphologically from yeast to hyphae in the host environment. Oxidative stress tolerance and morphological changes of T. asahii are regulated by Hog1, a mitogen-activated protein kinase. The role of Hog1 in the biofilm formation by T. asahii, however, has remained unknown. In the present study, we demonstrated that a hog1 gene-deficient T. asahii mutant formed excess biofilm under a rich medium in vitro, but did not form biofilm in an in vivo evaluation system using silkworms. The hog1 gene-deficient T. asahii mutant formed a greater amount of biofilm than the parent strain in vitro. Under an oxidative stress condition in vitro, however, lower amounts of biofilm were formed by the hog1 gene-deficient T. asahii mutant than by the parent strain. In an in vivo evaluation system using silkworms, lower amounts of biofilm were formed by the hog1 gene-deficient T. asahii mutant than by the parent strain. Our findings suggest that Hog1 regulates biofilm formation by T. asahii in response to host environmental conditions, including oxidative stress.
Topological transition in filamentous cyanobacteria: from motion to structure
Authors: Cammann Jan , Faluweki Mixon K. , Dambacher Nayara , Goehring Lucas , Mazza Marco G.
Published: November 2024

Many active systems are capable of forming intriguing patterns at scales significantly larger than the size of their individual constituents. Cyanobacteria are one of the most ancient and important phyla of organisms that has allowed the evolution of more complex life forms. Despite its importance, the role of motility on the pattern formation of their colonies is not understood. Here, we investigate the large-scale collective effects and rich dynamics of gliding filamentous cyanobacteria colonies, while still retaining information about the individual constituents’ dynamics and their interactions. We investigate both the colony’s transient and steady-state dynamics and find good agreement with experiments. We furthermore show that the Péclet number and aligning interaction strength govern the system’s topological transition from an isotropic distribution to a state of large-scale reticulate patterns. Although the system is topologically non-trivial, the parallel and perpendicular pair correlation functions provide structural information about the colony, and thus can be used to extract information about the early stages of biofilm formation. Finally, we find that the effects of the filaments’ length cannot be reduced to a system of interacting points. Our model proves to reproduce both cyanobacteria colonies and systems of biofilaments where curvature is transported by motility.
Sex-specific regulatory architecture of pancreatic islets from subjects with and without type 2 diabetes
Authors: Qadir Mirza Muhammad Fahd , Elgamal Ruth M , Song Kejing , Kudtarkar Parul , Sakamuri Siva S V P , Katakam Prasad V , El-Dahr Samir S , Kolls Jay K , Gaulton Kyle J , Mauvais-Jarvis Franck
Published: November 2024

Patients with type 2 and type 1 diabetes (T2D and T1D) exhibit sex-specific differences in insulin secretion, the mechanisms of which are unknown. We examined sex differences in human pancreatic islets from 52 donors with and without T2D combining single cell RNA-sequencing (scRNA-seq) and single nucleus ATAC-sequencing (snATAC-seq) with assays probing hormone secretion and bioenergetics. In non-diabetic (ND) donors, sex differences in islet cell chromatin accessibility and gene expression predominantly involved sex chromosomes. In contrast, islets from T2D donors exhibited similar sex differences in sex chromosome-encoded differentially expressed genes (DEGs) as ND donors, but also exhibited sex differences in autosomal genes. Comparing β cells from T2D and ND donors, gene enrichment of female β cells showed suppression in mitochondrial respiration, while male β cells exhibited suppressed insulin secretion, suggesting a role for mitochondrial failure in females in the transition to T2D. We finally performed cell type-specific, sex stratified, GWAS restricted to differentially accessible chromatin peaks across T2D, fasting glucose, and fasting insulin traits. We identified that differentially accessible regions overlap with T2D-associated variants in a sex- and cell type-specific manner.
Ligand Field Theory
Authors: Kaizaki Sumio
Published: November 2024

The basics of ligand field theory are described together with the angular overlap model as background for Chapter 2. Followed by an explanation of the d orbitals splitting in the weak and strong crystal fields, the ground and the excited states of the d electron terms are discussed on the basis of the crystal field theory (Orgel diagram) and the ligand field theory or Tanabe–Sugano diagram with the help of a brief introduction to group theory in the Appendix. These subjects are helpful to understand the metal–ligand interactions or physical properties other than optical spectroscopy in Chapter 2 for instrumental analysis of coordination compounds.
Single Crystal X-ray Structure Analysis
Authors: Ozeki Tomoji
Published: November 2024

A quick practical guide for structure analysis using single-crystal X-ray diffraction will be presented. This chapter aims to provide a rough idea of the method rather than explaining the theory in detail. Therefore, the use of mathematical equations has been kept to a minimum. Particular emphasis has been put on space-group notations and disorder since they are not easy to understand for those unfamiliar with crystallography.
Laboratory development and validation of vapor phase PFAS methods for soil gas, sewer gas, and indoor air
Authors: Hayes Heidi , Lutes Chris , Watson Nicola , Benton Diane , Hanigan David J. , McCoy Seth , Holton Chase , Bronstein Katherine E. , Schumacher Brian , Zimmerman John , Williams Alan
Published: November 2024

A thermal desorption GC-tandem MS method was developed to measure vapor-phase PFAS and their potential migration into indoor air.
Bandgap-engineered In2S3 quantum dots anchored on oxygen-doped g-C3N4: forging a dynamic n–n heterojunction for enhanced persulfate activation and degradation of metronidazole
Authors: Mishra Soumya Ranjan , Gadore Vishal , Roy Saptarshi , Ahmaruzzaman Md.
Published: November 2024

A novel n–n heterojunction catalyst was fabricated by anchoring In2S3 QDs onto oxygen-doped g-C3N4, achieving 98.17 ± 1.53% efficiency in degrading metronidazole via persulfate activation under visible light irradiation within 25 min.
Fruit exosomes: a sustainable green cancer therapeutic
Authors: Das Asmit , Sonar Swarup , Kalele Ketki , Subramaniyan Vetriselvan
Published: November 2024

Fruit exosomes are the source of natural cancer therapeutic tools.
Novel polymer/halloysite composites with high halloysite content and remarkable mechanical strength
Authors: Zhang Mingxuan , Sabatini Camila , Chen Kaiwen , Makowka Steven , Hu Ruijia , Swihart Mark , Cheng Chong
Published: November 2024

Facilitated by interfacial H-bonding interactions, polymer/halloysite composites with high halloysite content and significantly enhanced mechanical properties have been achieved.
Natural peptides and their synthetic congeners acting against Acinetobacter baumannii through the membrane and cell wall: latest progress
Authors: Kumar Gautam
Published: November 2024

Acinetobacter baumannii is one of the deadliest Gram-negative bacteria (GNB), responsible for 2–10% of hospital-acquired infections.
Electronic and magnetic properties of the HfO2 monolayer engineered by doping with transition metals and nonmetal atoms towards spintronic applications
Authors: Han Nguyen Thi , Guerrero-Sanchez J. , Hoat D. M.
Published: November 2024

HfO2 monolayer has good stability. Further, doping with transition metals and light nonmetal atoms is proposed to modify its electronic and magnetic properties.
Recent advances in the synthetic applications of nitrosoarene chemistry
Authors: Lin Feng , Tang Rongzhi , Liu Sheng , Tan Yu
Published: November 2024

This review covers reactions involving nitrosoarenes over the last decade, including cyclization, reactions with attacks at the oxygen or nitrogen terminus, dimerization, rearrangement, coordination, and other significant reactions.
Rhodium(iii)-catalyzed direct C–H activation of 2-aryl-3H-indoles: a strategy for 4-heteroaryl pyrazole synthesis
Authors: Yang Zi , Luo Ji , Zhang Wenbo , Lei Jieni , Liu Chaoshui , Li Yaqian
Published: November 2024

A novel protocol for synthesizing 4-heteroaryl pyrazoles from readily available 2-aryl-3H-indoles and diazopyrazolones through the rhodium(iii)-catalyzed C–H bond activation has been achieved.
Controlling the solid-state and particle properties of a fixed-dose combination co-amorphous system by spray drying
Authors: Parkes Alice , Ziaee Ahmad , O'Reilly Emmet
Published: November 2024

Controlling the solid-state stability of co-amorphous systems has been an ongoing challenge in the pharmaceutical field to date. This study demonstrates how spray drying can be used to control the solid-state stability of a co-amorphous system.
Reconfiguration and activation induced by characteristic migration of transition metal ions between interfaces of high-entropy oxygen evolution catalysts
Authors: Zuo Wei , Xu Zhenhang , Qian Jun , Cheng Gongzhen , Zhao Pingping
Published: November 2024

Image illustrates the electrochemical reconfiguration behavior occurring on the surface of simulated high-entropy alloy catalysts during the electrocatalytic oxygen evolution reaction (OER) in alkaline medium.
Depolymerization of vulcanized poly(cyclopentene), poly(norbornene-ran-cyclopentene) and poly(endo-dicyclopentadiene-ran-cyclopentene) rubbers via ring-closing metathesis depolymerization for monomer recycling
Authors: Hayano Shigetaka , Kumazawa Kazuki , Isobe Kosuke , Sakurai Takuro , Wang Shengyang
Published: November 2024

Vulcanized, crosslinked cyclopentene-based rubbers were depolymerized to give a cyclopentene monomer with 80–90% yields.
Advances in plastic to fuel conversion: reactor design, operational optimization, and machine learning integration
Authors: Paavani Karnatakam , Agarwal Krutika , Alam Shah Saud , Dinda Srikanta , Abrar Iyman
Published: November 2024

Plastic waste management is a pressing global problem that requires sustainable solutions to mitigate environmental harm.
Enhanced photocatalytic hydrogen production efficiency using urea-derived carbon nitride in a continuous flow reactor
Authors: Batool Samar , Ibrahim Malek Y. S. , Ehrlich-Sommer Florian , Myakala Stephen Nagaraju , Naghdi Shaghayegh , Cherevan Alexey
Published: November 2024

In this study, we conducted a comprehensive comparison of the photocatalytic properties and the reactivity towards the hydrogen evolution reaction (HER) of carbon nitride (GCN) in batch and flow photo-reactors.
Cooperating with additives: low-cost hole-transporting materials for improved stability of perovskite solar cells
Authors: Mäkinen Paavo , Conelli Daniele , Grandhi G. Krishnamurthy , Suranna Gian Paolo , Vivo Paola , Grisorio Roberto
Published: November 2024

A low-cost approach for unconventional hole-transporting materials is reported. Their sustainable combination with the sole tert-butyl pyridine as an additive unprecedently stabilises the corresponding perovskite solar cells up to 400 days.
Correction: Controllable biomolecule release from self-assembled organic nanotubes with asymmetric surfaces: pH and temperature dependence
Authors: Kameta Naohiro , Minamikawa Hiroyuki , Masuda Mitsutoshi , Mizuno Go , Shimizu Toshimi
Published: November 2024

Correction for ‘Controllable biomolecule release from self-assembled organic nanotubes with asymmetric surfaces: pH and temperature dependence’ by Naohiro Kameta et al., Soft Matter, 2008, 4, 1681–1687, https://doi.org/10.1039/B803742F.
An ultra-sensitive covalent organic framework based smoldering sensor for early warning of a granary fire
Authors: Luan Yunlu , Zhan Jing , Ye Xiaojuan , Mu Xiaowei
Published: November 2024

To prevent granary fires, this paper analyzes the pyrolysis products of rice and proposes a novel granary smoldering early warning method based on the color reaction between furfural (main product during rice smoldering) and aniline hydrochloride.
Room-temperature spin-coatable polyoxometalate composites for high-contrast, large-area electrochromic capacitive films
Authors: Wang Shi-Ming , Wang Kai-Hua , Zhou Lu , Lu Tianyang , Kim Eunkyoung , Han Zhengbo , Lin Jun Liang , Liu Lin , Li Guodong
Published: November 2024

A room temperature spin-coating method for high performance polyoxometalate (POM)-based electrochromic (EC) capacitive films has been developed with the assistance of MOFs, enabling the fabrication of flexible POM-based EC films for the first time.
Ferroelectrically gated sub-6 nm monolayer MoS2 transistors for high-performance and low-power applications
Authors: Yuan Jin , Dai Jian-Qing , Zhao Miao-Wei , Zhong Yun-Ya , Deng Da-Wei
Published: November 2024

A schematic device model and the corresponding transfer characteristics with upward (P↑) and downward (P↓) polarizations of BiAlO3 at Vb = 0.64 V are presented.
Modeling of hydrogen release during electrolysis of alkaline solution
Authors: Chebakova Violetta
Published: November 2024

Electrochemical processes of electrolysis of solutions belong to heterogeneous processes, their most intensive development and flow occurs at the interface, namely at the contact line between the metal electrode and the liquid electrolyte. The paper describes an algorithm for solving the objective of calculating hydrogen evolution during electrolysis of alkaline electrolyte in one-dimensional approximation. This numerical algorithm makes it possible to predict the hydrogen yield, to find the rates of constants in electrode processes, as well as we calculate the concentrations of substances involved in electrode processes and their spatial distribution. The algorithm consists of two blocks. The first block is an independent objective to find rate constants of processes. Kinetic objectives make it possible to find rate constants of near-electrode processes and to estimate contributions of near-electrode processes. The second block is the solution of initial-boundary and boundary value objectives in the “one-dimensional” approximation. The difference schemes for solving these objectives are constructed by the integrointerpolation method on a uniform grid, and an explicit difference scheme is used for solving the initial-boundary objectives of the charged particle balance. Calculation of the amount of separated gas showed good convergence both at the cathode (hydrogen) and at the anode (oxygen). The calculation of the spatial ones showed characteristic gradients, i.e., rather qualitative convergence.
Influence of radiation defects on the photoelectric properties of polycrystalline CDTE films with deep impurity levels
Authors: Abdullayev Sherzod , Otajonov Salim , Alimov Nodir
Published: November 2024

In this paper, the effect of boron implantation at doses of 9⋅1014 cm-2 on the deep-level spectra of polycrystalline CdTe films doped with silver is considered. It was found that boron implantation results in the formation of radiation defects in the region close to the surface of 0.2 μm. It was determined that the location of deep local levels, the activation energy of which is equal to Ec-1.15 eV, is located in the intercrystal barriers. The implanted CdTe: Ag layers are thermally treated for 30 min at a temperature of 100⁰C and the restoration of the barriers in these layers is shown: the interlayer grows and the concentration of levels participating in the photovoltage increases. Heating of non-implanted layers under the same conditions does not affect the shape of the primacy absorption spectra, but only increases its value in its own region by 1.4 times, i.e. heating improves the barriers only in the implanted layers.
Efficiency of using a solar air heating collector in a continental climate
Authors: Madaminov Javlonbek , Ergashev Ilhom , Rustamova Mukhlisa , Tohirov Islomjon , Kodirov Murodjon , Valixonov Dostonbek , Mirzayev Murodiljon
Published: November 2024

This article presents a comprehensive technical and economic analysis of the implementation of solar air collectors (SAC) in the Fergana region of the Republic of Uzbekistan. Characterized by a continental climate, the Fergana region enjoys a remarkable abundance of solar resources, with sunshine durations reaching between 2900 to 3100 hours annually. The text delves into the region’s climatic conditions, focusing on key metrics such as average annual temperature, total solar radiation, and the extent of sunshine hours. By assessing the operational efficiency of SAC under varying climatic circumstances specific to areas like Fergana, Kokand, and Shakhimardan, the study provides valuable insights into the potential of solar energy solutions. This research represents a significant advancement in promoting renewable energy sources in the region, highlighting their importance as a means to reduce reliance on traditional energy systems and to enhance environmental sustainability. The article aims to encourage stakeholders to adopt solar technologies, fostering a transition toward a greener, energy-independent Uzbekistan.
Conditional creation of superpositions of coherent states with an ineffective photon
Authors: Sattarkulov K.R. , Komilov M.M. , Obidova Z.N. , Imankulov N.T. , Fayzullayev A.K.
Published: November 2024

The article shows that a single photon source and straightforward, purely optical processes can be used to produce a linear superposition of two macroscopically identifiable optical coherent states. A superposition of coherent states in a freely propagating optical field with high coherence amplitude can be generated via weak squeezing on a single photon, beam mixing with an auxiliary coherent state, and photon detection with imperfect threshold detectors. (α>2) and F=0.99, which is extremely precise. Our technique does not require a precise photon count, resolving measurements, or nonlinear Kerr-type interactions, in contrast to all existing schemes for obtaining such a state. It also exhibits some tolerance to inefficiencies in photon generation and is robust against detection of inefficiencies.
Modeling of a non-stationary process of gas outflow into a closed area filled with liquid with a tube array
Authors: Alekseev Maksim , Lezhnin Sergey
Published: November 2024

Numerical modeling was carried out in a two-dimensional formulation of the process of outflow of an air stream into a closed area filled with liquid, in which there was a “chessboard” tube array. Liquids with significantly different densities (water, heavy liquid metal) are considered. It is shown that the process of the first pulsation of a gas cavity in such a region for liquid metal and water occurs in a similar way. The main difference between the outflow of gas into liquid metal and water is the rate of expansion and compression of the gas cavity. The rate of expansion and contraction of a cavity in liquid metal is approximately 2.9-3.5 times less than in water. The emergence of vortex structures behind the upper row of the tube array was discovered during the deceleration of the liquid in the maximum compression phase of the upper gas volume. It has been shown that the maximum pressure during compression of the upper gas volume can reach up to 300 MPa for liquid metal and up to 75 MPa for water (at a pressure in the outflow area equal to 18 MPa).
Regular large waves on thick falling liquid films
Authors: Cherdantsev Andrey , Isaenkov Sergey , Markovich Dmitry
Published: November 2024

Here we investigate the possibility to create regular waves on falling liquid films that would survive for long distances. The flow is investigated in a 20-mm vertical pipe at the distance of 145-180 cm from the inlet for Reynolds numbers from 140 to 400. The regular waves were created by periodic pulsations of liquid flow rate with preset frequency and amplitude at the inlet. The spatiotemporal records of local instantaneous film thickness were obtained with brightness-based laser-induced fluorescence technique. Creation of regular waves is possible within a relatively narrow range of small (up to 10 Hz) frequencies, which expands as liquid flow rate is increased. These waves survive for at least 90 pipe diameters, in contrast to wider studied cases of high-frequency excited waves on low Reynolds number films. The excited waves are similar to the disturbance waves in gas-liquid annular flow, but they do not generate fast ripples on their surface and produce no entrainment.
Levitation of microdroplets above an evaporating layer of water
Authors: Derevyannikov Ivan , Marchuk Igor , Kabov Oleg
Published: November 2024

The paper investigates a levitating array of microdroplets above a heated layer of distilled degassed water with an area of 40×40 mm2. The droplets are distributed unevenly, and most of them accumulate at the edges of the test section. The coalescence of droplets with the liquid layer is studied. It is shown that with increasing liquid layer temperature, the average diameter of the coalescing microdroplets increases.
Analysis of vortex structures in problems of computational fluid dynamics
Authors: Goryachev Valery
Published: November 2024

The article discusses methods for identifying vortex structures when analyzing the results of numerical simulations in hydro- and gasdynamics, thermophysics, and in applications. The structures were identified in an authorized visualization system using additional processing of scalar, vector and tensor fields. The technique is illustrated with examples of visualization of simulation results in computational fluid dynamics and astrophysics. Data processing was carried out using topological description methods.
Oscillating solid sphere and fluid flow in an axisymmetric sinusoidal channel: Light and heavy body cases
Authors: Karpunin Ivan
Published: November 2024

The dynamics of a solid spherical body in a “hold-up” state caused by an oscillating fluid flow in an axisymmetric channel is investigated experimentally. The shape of the channel is sinusoidal, i.e., the radius varies periodically along its axis. The effect is studied for bodies of different size and relative density to the fluid. The effect of fluid viscosity, amplitude and frequency of oscillation of the fluid column is studied. The intensity of the averaged flows is analyzed. Particular attention is paid to the methodology of data processing of averaged flows. The experimental data are generalized to the plane of the control dimensionless parameters.
Flow boiling bubble dynamics in a graphene-coated minichannel
Authors: Kochkin Dmitry , Belosludtsev Valentin , Zaitsev Dmitry , Arkhipov Vyacheslav , Kabov Oleg
Published: November 2024

This paper is devoted to the study of the dynamics of vapor bubbles during water flow boiling in a graphene-coated minichannel. Graphene was synthesized directly on the surface of the boiling surface. It was found that applying a graphene film to a copper surface does not lead to a significant change in wettability with water. During the experiments, a significantly larger number of bubbles were observed on the graphene-coated surface than on the surface without graphene.
Study of the dynamics of a helical vortex with use of the Local Induced Approximation
Authors: Kuibin Pavel
Published: November 2024

A problem on origin of the instability of a conical helical vortex, which manifests itself in the distortion of the original shape, the convergence of the spiral turns, and the formation of loop-like structures, preceding subsequent vortex reconnection. For modelling the phenomenon, an economical method is used to calculate the dynamics of a vortex filament based on the Local Induction Approximation. The characteristics of the instability parameters are revealed depending on the geometric characteristics of the vortex.
Mathematical modeling of cloudy ice thawing
Authors: Savvinova Nadezhda A. , Sleptsov Semen D.
Published: November 2024

The mathematical model of melting ice with inclusions in the form of gas bubbles (cloudy ice) is a problem of radiation-conductive heat transfer in a semitransparent two-phase medium that selectively absorbs and scatters radiation during radiation heating by an external source of thermal radiation. The mathematical problem statement represents the single-phase formulation of the Stefan problem. The temperature distributions and radiation fluxes in a flat layer of melting ice, the rate of ice melting were calculated by a numerical method. To solve the radiation transfer equation was used a modified mean flux method, which allows taking into account a wide range of optical properties of the two-phase medium and the source of thermal radiation. The influence of anisotropic scattering and strong absorption of radiation by the gas contained in the bubbles on the intensity of heating and melting of the ice layer was studied.
Investigation of immersion media and materials for optical diagnostics in curved wall channels by the matching index of refraction
Authors: Panteleev Semen , Tokarev Mikhail
Published: November 2024

Five different refractive liquids and two possible transparent solid materials were tested to perform matched index of refraction (MIR) optical flow measurements and visualisation in channels with curved walls, for example, models of rods in fuel assemblies. The results of the tests showed that the selection of refractive liquid is always a compromise between effective and sometimes hazardous substances such as p-Cymene or essential oils and their less harmful substitutes with higher dynamic viscosity, such as white mineral oil.
Investigation of local heat fluxes in the contact line area during the growth of a single vapor bubble under microgravity conditions
Authors: Zorkina Anastasia , Ronshin Fedor , Kabov Oleg , Rednikov Alexey , Tadrist Lounès
Published: November 2024

The present work is devoted to the study of heat fluxes from a heating surface into a liquid during single vapor bubble growth. The experiment was conducted as part of the RUBI (Reference mUltiscale Boiling Investigation) boiling project implemented on the International Space Station between 2019 and 2021. Since microgravity increases the spatial and temporal resolution of the problem, this made it possible to study in detail the processes of heat and mass transfer in the area of a three-phase contact line. The paper presents a developed algorithm for determining heat fluxes and the amount of heat transferred from various zones at different experimental parameters: from the contact line area, from the centre under the bubble and from the liquid-vapor interface. In particular, it is shown that it is in the area of the contact line that the maxima of heat fluxes are observed and that evaporation from this area makes a significant contribution to the growth of the bubble (about 50%).
The geometric and dynamic dimensions of segner-type jet turbines for low-pressure water sources
Authors: Urmonov Sanjarbek , Boynazarov Bekzod , Madaminov Javlonbek , Nasretdinova Feruza , Toxirov Muxammadrafiq , Odilov Sanjarbek
Published: November 2024

Today, the production of electricity from renewable energy sources is a priority for all countries. Specifically, there is extensive scientific research being conducted on the effective use of small and low-pressure water sources for electricity generation. This research focuses on the creation and improvement of hydropower devices in numerous leading scientific and higher educational institutions worldwide. This article investigates a jet turbine based on a Segner wheel operating in low-pressure water sources.The study examines how the geometric shape and the number of nozzles of a hydraulic turbine affect the speed and pressure changes of a moving water flow at various points. This analysis is performed through mathematical modeling using COMSOL Multiphysics version 6.1 (Build: 282), which employs a standard RANS method for nozzles of five different geometric shapes in the CFD module, specifically in the Turbulent Flow, k-ε model.To determine the optimal geometric shape of the nozzle, the study divided the water at the nozzle inlet into water bundles. Triangles were formed based on the impact direction of each water clot on the nozzle’s inner walls, directed toward the center of the outlet. These were determined by the horizontal coordinates of the impact points of each water clot on the nozzle. Modeling was conducted in both two- and three-dimensional spaces, utilizing the k-ε model in an automated system specifically designed for plane shear layers and turbulent flows. This model includes the smallest set of equations to minimize unknown quantities in processes involving all natural heat and liquid flows.The study achieved favorable results when calculating shear stresses and Reynolds tensors for a medium with a small pressure gradient. The initial kinematic and dynamic parameters used in the model were determined based on formulas discussed in the previous chapter.
Neural networks for bioreactor control solutions
Authors: Miroshnikov Sergey , Ryazanov Vitaliy , Proskurin Dmitry , Sheida Elena , Miroshnikov Ivan , Ovechkin Maxim , Duskaev Galimzhan
Published: November 2024

The use of machine learning has the potential to improve the control of bioreactors. The aim of this research was to use self-organising Kohonen maps based on algorithms built from the composition of the taxonomic structure of the bioreactor. By adjusting the weights of the map neurons, we can infer internal unobservable dependencies in the input data structures based on the results. Using our chosen model, we will gain a deeper understanding of the taxonomic composition of the bacterial community, which will allow us to better manage fermentation processes in bioreactors.
Improvement of hydraulic parameters of heat supply water heating boilers
Authors: Arifjanov Aybek , Kurbanov Kozim , Xoshimov Sardor
Published: November 2024

Practical and theoretical research has been carried out to optimize thermal energy use and incorporate energy-saving methods in consumption and production processes. This article presents an analysis of research on heat transfer by improving its hydraulic parameters in order to increase the energy efficiency of water heating boilers designed for heat supply of private residences and social facilities today. The research includes both practical experiments and theoretical analysis to ensure efficient thermal energy utilization. A program was developed to use the least squares method for analyzing test results on pipes of various cross-sections, aimed at evaluating the efficiency of heat transfer surfaces. The study found that pipes with corrugated inner walls in heat exchangers exhibited 15-20% higher efficiency compared to regular pipes, enhancing the plant's thermal energy efficiency. Implementing the proposed device for boiler pipes in manufacturing enterprises could allow for the construction of additional facilities, such as greenhouses, fruit drying shops, and service buildings. This innovation enables the production and use of low-cost hot water, potentially generating additional income in the production of bricks or porcelain.
Theoretical and Experimental Problems of the Problem of Rotation of a Heat-Conducting Solid Relative to a Fixed Point
Authors: Groshev Artem , Antsiferova Valentina , Deniskin Yury , Solovyeva Elena
Published: November 2024

The article investigates a variant of a non-relativistic model of the motion of a rigid body in a uniform magnetic field described by a system of differential equations in a deterministic problem of the rotation of an isotropic body relative to the center of inertia fixed in the geometric center and offers experimental characteristics of the studies, the results of tests of the inductive orientation system of a moving homogeneous body. Thus, the article covers both theoretical and practical issues of the dynamics of rigid bodies under the influence of a magnetic field, offering methods and approaches to controlling their orientation and motion.
Analysis of modern methods for calculating nozzle assemblies in pressure vessels
Authors: Ponikarov S. I. , Ponikarova I. N.
Published: November 2024

The paper is focused on the analysis of modern methods of calculation of socket assemblies in pressure vessels. Socket assemblies are important elements of high-stress pressure vessel structures. The authors review traditional and modern design methods, including the Finite Element Method (FEM) and empirical approaches such as the Welding Research Council (WRC) recommendations. The advantages of using FEM are discussed, as it allows for complex geometric and loading conditions that are critical to reliable design. The paper also discusses the effects of geometric parameters, new materials and coatings, and various joint strengthening methods. Results from parametric analysis and experimental research are presented, confirming the importance of accurate modeling in ensuring the durability and safety of pressure vessels.
Improvement of energetic efficiency of heating transport systems in the far north of Siberia based on computer modeling and design
Authors: Mescheryakov Sergey , Solodilova Natalia , Lvov Alexey
Published: November 2024

The organization structure of energetic systems in Siberia, Russia, is investigated using real experimental data from the Far North region of Yakutia having permanent frost. Computer modeling technology is applied to control the amount of energetic loss of heating temperature using thermal, material, and geometric parameters. The example of experimental calculation results of a single energetic transport pipeline is given.
Determining actual phase velocity for flow hydrodynamics modeling in centrifugal apparatus packing
Authors: Salin A. A.
Published: November 2024

This paper presents the results of a performance study of nozzle centrifuges designed to optimize mass transfer processes under centrifugal field conditions. The study includes an analysis of the design features of the apparatus, such as the geometry of the nozzles and rotors, and their influence on the efficiency of phase separation. A theoretical framework based on the Bernoulli equation and similarity criteria (Froude, Reynolds and Weber) is presented and adapted to describe the hydrodynamics of two-phase flows. Experimental data show that the use of X-shaped and wave-shaped nozzles helps to reduce phase slippage and increase apparatus performance. The developed dependencies for calculating the actual circumferential flow velocity can be used for numerical simulation and further optimization of centrifugal apparatus design.
Reliability and safety issues of pipeline valves in mechanical engineering
Authors: Valeev S. I.
Published: November 2024

The condition for safe operation of technological systems of hazardous production facilities is the correct selection and reliable operation of valves. This paper presents the results of numerical modelling of shut-off valves in dependence on various operating conditions in order to determine their reliable and safe operation. The most common type of valve used is the needle valve. The hydrodynamic and strength conditions of the needle valve are modelled in the Ansys Fluent system. The results obtained made it possible to identify the weak points of the valve studied, to determine the maximum stresses that occur during its operation, and to determine its reliability.