bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-range velocity correlations from active dopants
Authors: Abbaspour Leila , Mandal Rituparno , Sollich Peter , Klumpp Stefan
Published: August 2024

Active matter systems display collective behaviors that are impossible in thermodynamic equilibrium. One such feature, observed in in dense active matter systems is the appearance of long-range velocity correlations without explicit aligning interaction. However, the conditions for the appearance of these correlations remain largely unexplored. Here we show that such long-range velocity correlations can also be generated in a dense athermal passive system by the inclusion of a very small fraction of active Brownian particles. We develop a continuum theory to explain the emergence of velocity correlations generated via such active dopants. We validate the predictions for the effects of magnitude and persistence time of the active force and the area fractions of active and passive particles using extensive Brownian dynamics simulation of a canonical active-passive mixture. Our work decouples the roles that density and activity play in generating long-range velocity correlations in such exotic non-equilibrium steady states.
The evolving genetic landscape of telomere biology disorder dyskeratosis congenita
Authors: Tummala Hemanth , Walne Amanda J , Badat Mohsin , Patel Manthan , Walne Abigail M , Alnajar Jenna , Chow Chi Ching , Albursan Ibtehal , Frost Jennifer M , Ballard David , Killick Sally , Szitányi Peter , Kelly Anne M , Raghavan Manoj , Powell Corrina , Raymakers Reinier , Todd Tony , Mantadakis Elpis , Polychronopoulou Sophia , Pontikos Nikolas , Liao Tianyi , Madapura Pradeep , Hossain Upal , Vulliamy Tom , Dokal Inderjeet
Published: August 2024

Dyskeratosis congenita (DC) is a rare inherited bone marrow failure syndrome, caused by genetic mutations that principally affect telomere biology. Approximately 35% of cases remain uncharacterised at the genetic level. To explore the genetic landscape, we conducted genetic studies on a large collection of clinically diagnosed cases of DC as well as cases exhibiting features resembling DC, referred to as ‘DC-like’ (DCL). This led us to identify several novel pathogenic variants within known genetic loci and in the novel X-linked gene, POLA1. In addition, we have also identified several novel variants in POT1 and ZCCHC8 in multiple cases from different families expanding the allelic series of DC and DCL phenotypes. Functional characterisation of novel POLA1 and POT1 variants, revealed pathogenic effects on protein-protein interactions with primase, CTC1-STN1-TEN1 (CST) and shelterin subunit complexes, that are critical for telomere maintenance. ZCCHC8 variants demonstrated ZCCHC8 deficiency and signs of pervasive transcription, triggering inflammation in patients’ blood. In conclusion, our studies expand the current genetic architecture and broaden our understanding of disease mechanisms underlying DC and DCL disorders.
Multifunctional Electrocatalysis: Fundamentals and Future Directions
Authors: Isaac Bikash Ranjan , Mallick Prayash , Pillai Vijayamohanan K.
Published: August 2024

Electrocatalysis is a vibrant field of chemistry, materials science, and energy technology since electrochemical processes promote the enhanced efficiency of various applications, ranging from electrolysers and fuel cells for energy storage devices to the electro-organic synthesis of many important drugs and intermediates. This chapter provides a comprehensive overview of core electrochemical concepts in electrocatalysis, elucidating the interplay of various multifunctional sites and intermediates. Furthermore, the role of the electrocatalyst is explained in terms of the reaction kinetics and adsorption configuration of intermediates, diving into the molecular and electronic mechanisms. The chapter also explores strategies for synthesizing electrocatalytic materials and considers attributes such as stability, durability, and environmental impact. Moreover, with theoretical models and practical experimental findings, the underlying principles for solving the complexities of electrocatalysts, such as enhanced durability and early warning of degradation, are demonstrated with illustrative examples. Understanding such fundamental principles, concepts, and mechanisms is expected to foster the design of more robust, efficient, and inexpensive electrocatalysts with multiple advantages for sustainable energy conversion and environmental remediation.
Trifunctional Electrocatalysts for the Hydrogen Evolution Reaction (HER), Oxygen Evolution Reaction (OER), and Urea Oxidation Reaction (UOR)
Authors: Pataniya Pratik M. , Shah Ayushi , Sharma Pooja , Sumesh C. K.
Published: August 2024

The quest for alternative fuels has been investigated for many years owing to the storage constraints on fossil fuels and petroleum and the excessive carbon dioxide emissions following combustion. Recently, the use of hydrogen as a fuel has attracted substantial attention. Electrochemical water splitting has gained prominence as a crucial method of production that can be utilized to create clean hydrogen fuel that is sustainable, renewable, affordable, and efficient. Trifunctional electrocatalysts are substances with simultaneous catalytic activity for many electrochemical processes. Several energy conversion and storage applications require the simultaneous electrocatalytic activities of the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and an additional reaction, such as the urea oxidation reaction (UOR), which is why the design of such catalysts is of great interest. This chapter introduces the basic principles of electrochemical water splitting along with a detailed explanation of HER-, OER-, and UOR-based water-splitting mechanisms. How heteroatom doping, heterostructures, cocatalyst deposition, and surface modification can improve hydrogen generation is discussed, and the factors that affect the electrochemical performance are also examined. A promising research field with enormous potential for a range of energy conversion and storage applications is the creation of effective trifunctional electrocatalysts.
Tetrafunctional Electrocatalysts: Advantages and Limitations
Authors: Thapa L. , Raj C. Retna
Published: August 2024

The global call for combating climate change and meeting future energy demands requires innovative technologies. Electrochemical technologies for the conversion of polluting CO2 from industries and automobiles to value-added products and the storage of energy from renewable resources offer promising solutions. Efficient catalytic materials are required for electrochemical energy conversion and storage. Developing multifunctional catalysts for such applications is important as a single catalyst can be used for multiple reactions. This chapter provides a brief account of the tetrafunctional activity of electrocatalysts and their advantages and limitations.
Cyclically conjugated porphyrin trimers linked through benzo[4,5]imidazo[2,1-a]isoindole bridges
Authors: Han Ting , Sharma Prabha , Khetrapal Navneet , Wang Hong
Published: August 2024

Cyclically conjugated porphyrin trimers that display interesting photophysical properties were synthesized.
Acceleration of xenon kick-out exchange in a cryptophane host explained by ab initio simulation
Authors: Pollet Rodolphe , Dognon Jean-Pierre , Berthault Patrick
Published: August 2024

Study of the degenerate exchange involving two xenon atoms and a cryptophane via ab initio molecular dynamics reveals a faster reaction rate than for the more simple dissociative mechanism and a self-organization of the cage.
Revival of stifled luminescence in the Y2Sn2O7:Eu nanophosphor: circumventing the surface side effects by Zr–Eu synergy
Authors: Mal Dibya Kanti , Das Soumitra , Nigam Sandeep , Mandal B. P. , Kaiwart Rahul , Poswal H. K. , Sudarsan V. , Majumder C. , Tyagi A. K.
Published: August 2024

The present work deciphered an innovative pathway for evasion of surface-quenching effect in the Y2Sn2O7:Eu phosphor without compromising homogeneity in structural ordering or vicinal symmetry of the dopant across the dimensions of the nanophosphor.
Photochemically enhanced photocatalytic and magnetic properties of TiO2via Co(ii) ion implantation from a Co(ii)–picoline complex
Authors: Ayyakannu Sundaram Ganeshraja , Subramani Thirumurugan , Anbalagan Krishnamoorthy , Parvez Mohammad Khalid , Kumar Alagarsamy Santhana Krishna
Published: August 2024

The UV-triggered photocatalytic reaction between the Co(ii)–picoline complex and TiO2 forms Co(ii) sub-surface-implanted TiO2 nanoparticles, demonstrating potential for spintronics and visible-light photocatalysis.
Advancements and assessment of compressed carbon dioxide energy storage technologies: a comprehensive review
Authors: Ma Hailing , Tong Yao , Wang Xiao , Wang Hongxu
Published: August 2024

Compressed CO2 energy storage (CCES) is a promising energy storage option with benefits like easy liquefaction, high density, and environmental compatibility.
Clo-miR-14: a medicinally valued spice-derived miRNA with therapeutic implications in rheumatoid arthritis
Authors: Sarkar Ashish , Saquib Mohd , Chakraborty Debolina , Mann Sonia , Malik Swati , Agnihotri Prachi , Joshi Lovely , Malhotra Rajesh , Biswas Sagarika
Published: August 2024

Plant microRNAs (miRNA) are regularly consumed orally along with diet, gaining attention for their RNA-based drug potential because of their ability to regulate mammalian gene expression specifically at the post-transcriptional level. Medicinally valued plants are well known for their anti-inflammatory property; however, the contribution of their miRNA in managing inflammation has been less studied. We investigated miRNA from four medicinally valued regularly consumed spices, and validated one of the most potential miRNA ‘Clo-miR-14’ for its thermal stability, and absorption in the plasma samples of RA patient’s by RT-PCR. In vitro and in vivo studies were performed to investigate the effect of Clo-miR-14 in ameliorating rheumatoid arthritis (RA) like symptoms. Our results suggest that ‘Clo-miR-14,’ an exogenous miRNA present in Curcuma longa, absorbed through regular diet, has robust thermal stability at 100°C in humans. It significantly reduced pro-inflammatory cytokines (TNF, IL-1β, IL-6) and RA-like symptoms, suggesting that plant-based miRNA could be a promising candidate as an RNA-based drug for RA pathogenesis.
Polarized APSK modulation system with polymorphic SC signals
Authors: Akuon Peter O.
Published: August 2024

This paper discusses a new symbol modulation scheme known as polarized amplitude and phase shift keying, (‐APSK) modulation with four rings in its basic form. The new scheme maps power‐polarized symbol pairs on its constellation in order to increase the number of data symbols. ‐APSK exploits a symbol mapper based on a conjugate power splitting algorithm. Product modulation is applied, where a voltage signal of a specified amplitude and phase is multiplied by another current signal of a specified amplitude and phase, thus forming polymorphic signals in the product constellation. At the receiver, an isolated detection is performed, where the voltage signal is detected independently of the received current signal. A selection combining scheme is then used. The results depict unity peak‐to‐average power ratio and low average symbol energy, which is desirable for Green communications in 5G networks. It presents lower bit error rates when compared with the state‐of‐the art ‐ary quadrature amplitude modulation, with a signal‐to‐noise ratio gap of at least . The proposed analytical framework closely matches the simulations for bit error rates under .
An improved two‐degree‐of‐freedom ADRC for asynchronous motor vector system
Authors: Wan Changhui , Duan Na , Xie Guochao , Liu Yuang
Published: August 2024

This paper proposes an improved two‐degree‐of‐freedom active disturbance rejection controller for the coupling problem of asynchronous motor vector system. To simplify the analysis process and accommodate observers of different types, a unified expression based on different controllers for the system output is developed. The closed‐loop transfer function generated by the reference input and load disturbance is given. For the coupling problem of motor output speed and immunity, the structure of a higher‐order extended state observer is reconstructed. The extended state observer estimates both the output speed and the total system disturbance, which serve as feedback and feed‐forward compensation quantities. Compared to the PI controller and traditional active disturbance rejection controller, the proposed controller achieves decoupling of output response speed and immunity, simplifies the process of parameter tuning. Finally, simulation and experiment results verify the feasibility and effectiveness of the algorithm in this paper.
Testing the sources of the peculiar abundances in globular clusters
Authors: Vaca R. J. , Cabrera-Ziri I. , Magris G. C. , Bastian N. , Salaris M.
Published: August 2024

This work aims to analyze some of the polluters proposed in the self-enrichment scenarios put forward to explain the multiple populations in globular clusters (GCs), extending previous studies. Three scenarios with different polluter stars were tested: asymptotic giant branch stars (AGBs), high-mass interacting binaries (IBs), and fast rotating massive stars (FRMSs). With abundance data available from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey and ΔY estimates from precise Hubble Space Telescope (HST) photometry, twenty-six clusters were studied, increasing the number of clusters in previous studies by more than a factor of three. We also included the study of the abundances of N, C, Mg, and Al, extending previous studies that mainly focused on the abundances of He, O, and Na. In addition, we constructed an empirical model to test whether one could explain the chemical signatures of the “enriched” population of GC stars with a fixed source and dilution process based on empirical data. In agreement with work by other authors, we found that the proposed polluters can generally predict the qualitative abundance patterns in GC stars and in some cases quantitatively predict some elements, but in most cases when we compare the model yields with the observations, we find that they cannot explain the entire set of observed abundance patterns. The empirical model succeeds in reproducing the abundances of Al for a given ΔY (and vice versa), showing that there is a direct relationship between Al and He, with one increasing proportionally to the other. However, the empirical model fails to reproduce the observed abundances of Na and N, in agreement with the results of previous works. The observed decoupling between the maximum abundances of CNO-cycle elements such as N and Na with those of Al and He provides new information and constraints for future models and could take us a step closer to understanding the origin of the peculiar abundance variations of GC stars.
Morphological characteristics of skin thickness in postnatal ontogenesis of karabayir horses
Authors: Choriyev Otabek , Dilmurodov Nasriddin , Babanazarov Eshmakhamad , Karimov Mamaradjab , Mukhtarov Bakhtayoi , Rahmanov O’tkirbek , Yakhshiyeva Sarvinoz
Published: August 2024

The characteristics of changes in the morphometric dimensions of the skin of horses belonging to the “Karabayir” breed at various physiological stages of postnatal ontogenesis were studied. It was found that the thickness of the skin of various anatomical points of the horse’s body increases rapidly in the 2-3 age stages of postnatal ontogenesis, and in old horses, this indicator decreases, the thickness of the skin of the legs increases in the distal direction in connection with the morphofunctional properties, and the skin elasticity decreases. In connection with the effect of mechanical friction on the skin, it is noted that it is thin in the inner part of the thigh, and the thickest in the soft heel of the hoof, as well as somewhat thick in the lower part of the body of horses, and the thinnest in the ventral part of the head, neck, withers and abdomen. Also, it was found that the dermis of the skin in young horses, the subcutaneous layer (subcutis) thickens in middle-aged horses, and the dermis and subcutaneous layer thins and the skin elasticity decreases in old horses.
The influence of meteorological factors on air pollution in Tolyatti: Results of measurements from a mobile environmental laboratory
Authors: Shashenko Valeria , Melnikov Pavel , Gusev Dmitry , Selezneva Ksenia
Published: August 2024

The paper presents data from operational monitoring of atmospheric air in the city of Tolyatti, obtained through a mobile environmental laboratory in 2023. An assessment of the quality of atmospheric air in the city was carried out and a comparison of the concentrations of pollutants obtained as a result of measurements with the maximum permissible maximum one-time concentrations was presented. 37 excesses were identified and priority (most frequently detected) pollutants were identified. The correlation between recorded excesses of indicators and unfavorable weather conditions has been analyzed, and the wind direction in which exceedances of maximum permissible concentrations are most often recorded has been established. The principles of operation of the model of distribution of aerodisperse systems taking into account meteorological data have been formed.
Identification of melamine in milk using mid-infrared spectrometry
Authors: Kalyuzhnaya T. V. , Drozd A. V.
Published: August 2024

The paper presents a study of the infrared spectra of milk with melamine in the middle spectral range. The presence of absorption bands in the infrared spectra of a standard sample of melamine, milk without it and with its addition in different concentrations was analyzed in a comparative aspect. The presence of absorption bands of varying degrees of intensity in the infrared spectra has been established. It was revealed that the presence of melamine in milk can be identified by an absorption band in the region of 810 cm-1. The absence of this absorption band in the infrared spectra of milk with melamine concentrations of 0.1 and 0.5 mg/kg was determined. It was substantiated that the intensity of absorption bands in the infrared spectra depended on the concentration of melamine in milk. The use of spectrometry in the mid-infrared range to detect adulteration of milk has been proposed.
Identification of DNA markers of high protein content in pea seeds as a promising raw material for food production
Authors: Mironova Irina , Gainullina Karina , Slinkin Artem , Khabibullin Ilmir , Khabibullin Ruzel
Published: August 2024

The paper presents data reflecting the process of certification of peas as a promising plant raw material for food production. The elements of the crop structure and determination of the protein content in pea seeds were analyzed. Sources for selection have been identified that are characterized by high protein content in seeds, early ripening, high productivity, and resistance to biotic and abiotic factors. It is noted that typing using microsatellite markers makes it possible to create databases for identifying varieties and lines. This leads to the planning of effective hybridizations. identifying the most significant genetic polymorphism. According to phenological observations, accounting of elements of the crop structure and analysis of protein content in seeds for 2022-2023. 22 sources of selection-valuable traits were identified.
Assessment of the influence of testosterone concentration in blood serum on meat productivity and meat quality of Aberdeen Angus bulls
Authors: Frolov A. N. , Zavyalov O. A. , Aldyyarov T. B. , Mironova I. V. , Sycheva I. N.
Published: August 2024

The studies were carried out on Aberdeen Angus bulls at the age of 18 months. The animals, depending on the level of somatotropin in the blood serum, were divided into three groups using the percentile method: group I – up to the 25th percentile; Group II – within the 25-75 percentile; Group III – above the 75th percentile. Testosterone content was determined in blood serum by enzyme immunoassay using an automatic microplate analyzer Infinite F200 PRO. To study the meat qualities of the bulls, a control slaughter was carried out. It was established that bulls with the maximum concentration of testosterone in the blood serum were superior to individuals with the minimum concentration in pre-slaughter live weight by 3.4% (P≤0.05), in fresh carcass weight by 4.7% (P≤0.05), slaughter weight – by 3.6% (P≤0.01), pulp weight – by 5.4% (P≤0.05), protein accumulation in pulp – by 8.3% (P≤0.05), dry matter content – by 0.24% (P≤0.05), protein concentration – by 0.65% (P≤0.05), protein quality indicator – by 1.3% (P≤0.05) ). At the same time, they were inferior to them in weight and yield of internal fat by 12.1 (P≤0.001) and 0.6% (P≤0.05), respectively, in terms of bone content in the carcass - by 0.63% (P≤0 .05), relative fat content by 0.84% (P≤0.05).
Synthesis and characterization of silver nanoparticles obtained with the "green" method using spruce needles extract
Authors: Okonov Sanchir , Ovsuk Elena
Published: August 2024

This study explores the green synthesis of silver nanoparticles using spruce needles extract, a novel approach leveraging the bioactive compounds in the needles. The synthesized silver nanoparticles, characterized by scanning electron microscopy, exhibited an average size of 61.8 nm and good distribution within the organic medium. Antibacterial activity was evaluated using bacterial colony counts from a food sample (chicken wing flush). Two batches of silver nanoparticles were tested: the first with a 1:4 proportion of plant extract to 1mM AgNO3, and the second with a 1:9 proportion. The best antibacterial results were observed in the 1:9 proportion sample synthesized with both needles and branches, indicating the convenience of using unseparated plant material. The presence of the organic medium may influence antibacterial efficacy, suggesting the need for further research. Our antibacterial tests, conducted with a real food sample, provide relevant insights for potential applications in the food industry. This study demonstrates the feasibility of using spruce needles extract for sustainable silver nanoparticles synthesis, highlighting the potential for innovative applications in food safety and medical fields. Future research should focus on optimizing synthesis conditions and further characterizing the nanoparticles to enhance antibacterial performance.
Study of weeds and field plants of vegetable crops using the example of common potatoes
Authors: Mushinskiy Alexander , Saudabaeva Aliya , Panfilov Alexander , Pronko Nina , Vasilyeva Tatyana
Published: August 2024

This paper presents the results of a study showing that in an area with moldboard tillage there are 16 species of weeds belonging to the following families: Roaceae B., Polygonaceae J, Chenopodiaceae V., Amaranthaceae J., etc. It has been established that with no-mouldboard tillage soils in the study area grow 33 plant species belonging to different families, such as Roaceae B., Polygonaceae J, Chenopodiaceaevent, Rubiaceae, etc. It was revealed that the dominant plant species in the study area were: Amaranthus Retroflexus L., A. blitoides S. Watson, Conyza canadensis (L.) Crong and other harmful cosmopolitan perennials, such as:

Convōlvulus arvēnsis, Euphorbia waldstéinii, Cīrsium setōsum.
Nature-based solutions for contaminated site remediation: Key principles and a practical case
Authors: Tikhonova Irina , Guseva Tatiana , Grosheva Svetlana , Burvikova Juliana
Published: August 2024

The article considers opportunities applying nature-based solutions to remediate oil-contaminated sites. It is suggested using such industrial wastes as brewer’s spent grain, beet pulp, and lignin as structurers. It is demonstrated that structurers bearing such genes as Bacillus, Arthrobacter, etc. perform as active petroleum degraders. It was found out that the hydrocarbon removal rate ranged from 90 to 99% for all structurers studied. It is recommended using 1% of the lignin-based degrader to reduce hydrocarbon content in soils preparing them to the future phytoremediation.
The effectiveness of using ultrafine copper as part of an enzyme-containing diet for broiler chickens
Authors: Kamirova Ayna , Mustafina Aleksandra , Pavlova Marina
Published: August 2024

The purpose of the study was to study the effectiveness of using ultrafine copper particles as part of an enzyme-containing diet for broiler chickens. The research results indicate that each of the components of the proposed strategy influenced a certain functional system of the body with a subsequent range of adaptive changes, which ultimately led to a change in the efficiency of broiler rearing. In particular, it was found that the proposed substances have a growth-stimulating effect to varying degrees. Feeding the enzyme was accompanied by a maximum increase in the live weight of the experimental birds (13.75%), but in this case the maximum palatability of the feed was noted (a difference with the control of 6.7%). The strategy of complex introduction of enzyme and ultrafine copper was more effective and was accompanied by a decrease in feed costs in comparison with the group of introduction of only enzyme, with a difference in live weight with the control of 13.68%.
Psychometrische Evaluation der deutschen Version des Questionnaire of
Cognitive and Affective Empathy (QCAE)
Authors: Lübke Laura , Krogmann Diana , Spitzer Carsten
Published: August 2024

Empathie als zentrales Element der sozialen Kognition spielt eine entscheidende
Rolle in verschiedenen psychosozialen Bereichen und zwischenmenschlichen
Dynamiken, insbesondere auch im Kontext von Psychotherapie. Trotz der
Kontroverse um eine einheitliche Definition wird Empathie im Allgemeinen als
multidimensionales Konzept betrachtet, das kognitive und affektive Dimensionen
umfasst. Diese Differenzierung von kognitiven als auch affektiven Facetten
adressiert ein weit verbreitetes und international etabliertes
Selbstbeurteilungsverfahren zur Messung von Empathie, der Questionnaire of
Cognitive and Affective Empathy (QCAE). Die Evaluation der psychometrischen
Eigenschaften der deutschen Version des QCAE ist Gegenstand dieser Studie. Das
postulierte konfirmatorische Fünf-Faktoren-Modell zeigte in einer
Gelegenheitsstichprobe (N=1300) eine angemessene Passung an die zugrundeliegende
Struktur. Die Subskalen des QCAE zeigten eine zufriedenstellende interne
Konsistenz und konvergente Validität mit anderen Instrumenten zur Messung von
Empathie. Trotz einiger methodischer Einschränkungen legen die Ergebnisse nahe,
dass die deutsche Version des QCAE als reliables und valides Instrument zur
Erfassung von Empathie geeignet ist. Vor einer klaren Anwendungsempfehlung sind
weitere Untersuchungen in bevölkerungsrepräsentativen Stichproben und klinischen
Populationen erforderlich.
Advances in terminal management: simulation of vehicle traffic in container terminals
Authors: Carboni Angela , Deflorio Francesco , Caballini Claudia , Cangelosi Stefano
Published: August 2024

Controlling and managing traffic flows on internal roads in container terminals are crucial in achieving expected productivity levels and reducing negative externalities caused by congestion inside and outside the terminal areas. This paper proposes a simulation approach which terminal operators can use as a decision-support tool to assess the effects of their management strategies and improve terminal performance, resilience, and sustainability. A microscopic traffic simulation approach models key operations of a typical container terminal affecting road traffic flows. In particular, to estimate quantitative indicators, an import truck process is reproduced, considering the overlapping of the external truck and internal trailer flows. To measure environmental impacts, the model is extended with an instantaneous emissions model linked directly to the step-by-step traffic data. The proposed method is tested on a sector of the PSA Genova Pra’, the main Italian container gateway terminal. Performance indicators related to the terminal’s efficiency and sustainability are estimated, to compare alternative scenarios considering possible operational configurations and disturbance events, such as the closure of a part of the yard. By focusing on the interactions between vehicle flows and terminal equipment operations, this approach offers a new perspective on terminal operations, oriented both towards container terminal operators and stakeholders, such as road hauliers.
Heating and ventilation efficiencies of a solar chimney integrated system in a low-energy office building
Authors: Moosavi Leila
Published: August 2024

Mechanical air conditioning systems have a significant share of energy consumption in the building sector. Passive solar systems, such as solar chimneys, can reduce building energy demand by supplying space heating, cooling, and ventilation, significantly decreasing greenhouse gas emissions. Therefore, this study aimed to evaluate the heating and ventilation efficiencies of a solar chimney integrated system, including a roof solar chimney coupled with an air channel, for a two-story office building in Tehran, Iran. The studied system's conditions are switchable from heating to cooling by changing the opening positions. Computational Fluid Dynamics was employed to numerically investigate the heating and ventilation efficiencies of the proposed solar system. The results confirmed that the system could be utilized for pre-heating purposes during working hours but that the building should be ventilated only for 35% of this time with an air change rate of 0.8 during the year's coldest month. The arrangement could provide thermal and ventilation comfort for the occupied space only at solar intensity and ambient temperature higher than 550 W/m2 and 10 °C, respectively. In addition, the solar system could reduce 32% of the annual heating demand (918 kWh), which is equal to a reduction of 1865 kg of CO2 emissions during working hours.
Fundamental influence of irreversible stress–strain properties in solids on the validity of the ramp loading method
Authors: Shen Jingxiang , Kang Wei
Published: August 2024

The widely used quasi-isentropic ramp loading technique relies heavily on back-calculation methods that convert the measured free-surface velocity profiles to the stress–density states inside the compressed sample. Existing back-calculation methods are based on one-dimensional isentropic hydrodynamic equations, which assume a well-defined functional relationship P(ρ) between the longitudinal stress and density throughout the entire flow field. However, this kind of idealized stress–density relation does not hold in general, because of the complexities introduced by structural phase transitions and/or elastic–plastic response. How and to what extent these standard back-calculation methods may be affected by such inherent complexities is still an unsettled question. Here, we present a close examination using large-scale molecular dynamics (MD) simulations that include the detailed physics of the irreversibly compressed solid samples. We back-calculate the stress–density relation from the MD-simulated rear surface velocity profiles and compare it directly against the stress–density trajectories measured from the MD simulation itself. Deviations exist in the cases studied here, and these turn out to be related to the irreversibility between compression and release. Rarefaction and compression waves are observed to propagate with different sound velocities in some parts of the flow field, violating the basic assumption of isentropic hydrodynamic models and thus leading to systematic back-calculation errors. In particular, the step-like feature of the P(ρ) curve corresponding to phase transition may be completely missed owing to these errors. This kind of mismatch between inherent properties of matter and the basic assumptions of isentropic hydrodynamics has a fundamental influence on how the ramp loading method can be applied.
The leakage field characteristics of a large hybrid electromagnetic pulse simulator
Authors: Huang Qixiang , Li Junna , Wu Fangzheng , Li Shiji , Gong Yuhan , Zhou Xiaoyu , Shang Qin , Yang Tian
Published: August 2024

The leakage field of a hybrid electromagnetic pulse simulator with horizontal polarization is simulated and experimentally investigated based on the finite integration technique in this paper. The field distribution characteristics and far-field radiation pattern of the simulator are given. The attenuation characteristics of the electric field at specific directions in the z = 2 m plane are also predicted by numerical data fitting. Finally, according to the ICNIRP guidelines, the safe distances that satisfy the occupational and public exposure limits are obtained, and the safety regions lower than the reference levels are given. Results show that the electric field in the α = 0° direction is mainly contributed by the main polarization component (Ey), while the total electric field in the α = 90° direction also requires consideration of the vertical component (Ez). The dominant radiation direction in the z = 2 m plane lies between α = 0° and 30°, which poses the highest demand for the safe distance around the simulator. In addition, impedance mismatch and ground reflection are the main factors affecting the waveforms of the radiated electric field.
Effects of adding methane on the growth and electrical properties of GaN in oxide vapor phase epitaxy
Authors: Usami S. , Higashiyama R. , Imanishi M. , Takino J. , Sumi T. , Okayama Y. , Yoshimura M. , Hata M. , Isemura M. , Mori Y.
Published: August 2024

GaN grown via oxide vapor phase epitaxy (OVPE-GaN) can produce free-standing substrates with ultra-low resistivity because of the high doping concentration of oxygen. The bulk growth of OVPE-GaN is hindered by polycrystals generated during long-term growth. We have previously reported that thicker films can be grown by reducing the partial pressure of water vapor in the growth atmosphere with CH4. However, as CH4 is a dopant of carbon, a compensating acceptor, its addition may increase electrical resistance. In this study, we further investigated the effect of reducing water vapor partial pressure on polycrystals by combining Ga2O production (reaction of Ga and water vapor: a Ga–H2O system), which can reduce water vapor, with CH4 addition. However, CH4 addition to the Ga–H2O system increased polycrystal generation, possibly owing to the thermal decomposition of excess CH4. The properties of OVPE-GaN with CH4 addition were also evaluated. Although the CH4 addition resulted in high carbon doping, the carbon-doped OVPE-GaN maintained low resistivity. This is because the OVPE method involves three-dimensional growth with growth pits, and the growth pits leave behind low-resistivity high-oxygen-concentration regions. As the resistivity remains low even when CH4 is added in the OVPE method, both polycrystallization suppression and low resistivity can be achieved by selecting an appropriate CH4 flow rate.
Size-dependent growth dynamics of silver–gold core–shell nanoparticles monitored by in situ second harmonic generation and extinction spectroscopy
Authors: Babayode Daniel A. , Peterson Stena C. , Haber Louis H.
Published: August 2024

The in situ growth dynamics of colloidal silver–gold core–shell (Ag@Au CS) nanoparticles (NPs) are studied using time-dependent second harmonic generation (SHG) and extinction spectroscopy. Four sequential additions of chloroauric acid, sodium citrate, and hydroquinone are added to a silver nanoparticle solution to form a gold shell around a 45 nm silver core under different reaction conditions, resulting in final sizes ranging from 80 to 125 nm in diameter. In the first addition, a bumpy, urchin-like surface morphology is produced, while the second, third, and fourth additions provide additional nanoparticle growth with the surface morphology becoming more smooth and uniform, as shown using transmission electron microscopy measurements. The in situ extinction spectra increase in intensity for each addition, where blue-shifting and spectral narrowing are observed as the Ag@Au CS NPs grow in size. The extinction spectra are compared to Mie theory simulations, showing general agreement at later stages of the reactions for smooth CS surfaces. The in situ SHG signal is dominated by surface-enhanced plasmonic hotspots at the early stages of the shell growth, followed by gradual decreases in signal as the surface becomes more smooth. Two-photon fluorescence is also monitored during the CS growth, showing complementary information for comparisons to the extinction and SHG results. The holistic study of the synthesis and characterization of Ag@Au CS nanoparticles using in situ SHG spectroscopy, extinction spectroscopy, and Mie theory simulations allows for a comprehensive analysis of the complex growth dynamics occurring at the nanoscale for developing optimized plasmonic nanomaterial properties.
Measurement of the optical stiffness of photophoretic force tweezers in air
Authors: Zhu Haipeng , Cheng Xuemei , He Delong , Liu Tianye , Bai Jinbo
Published: August 2024

We report on a method of measuring the stiffness in photophoretic force tweezers in air by using an experimental configuration with two counter-propagating hollow beams. By setting the optical traps of both beams in the same focal plane of the camera, we are able to record the flight procedure of a trapped particle into the other trap after the initial trapping beam is switched off. Then, the stiffness of optical trap can be obtained by fitting the relationship of particle position vs time during the flight procedure. It is found that the measurement is tolerant to the distance between the traps and laser power variation. In addition, the measured stiffness is demonstrated applicable in determining the size of aerosol particles. The reliable method provided in this work is not only useful in studying the physical behavior of signal particle under atmosphere condition but also meaningful in the applications of aerosol studies, such as in situ aerosol characterization and the local surrounding environment sensing.
The fast committor machine: Interpretable prediction with kernels
Authors: Aristoff David , Johnson Mats , Simpson Gideon , Webber Robert J.
Published: August 2024

In the study of stochastic systems, the committor function describes the probability that a system starting from an initial configuration x will reach a set B before a set A. This paper introduces an efficient and interpretable algorithm for approximating the committor, called the “fast committor machine” (FCM). The FCM uses simulated trajectory data to build a kernel-based model of the committor. The kernel function is constructed to emphasize low-dimensional subspaces that optimally describe the A to B transitions. The coefficients in the kernel model are determined using randomized linear algebra, leading to a runtime that scales linearly with the number of data points. In numerical experiments involving a triple-well potential and alanine dipeptide, the FCM yields higher accuracy and trains more quickly than a neural network with the same number of parameters. The FCM is also more interpretable than the neural net.
Turbulent boundary layer structures downstream of a square cylinder
Authors: Wang Ping , Zhou Zhiqi , Chen Zhizong , Sung Hyung Jin , Liu Yuan , Wu Jianjun
Published: August 2024

Particle image velocimetry is used to investigate the coherent structures within a turbulent boundary layer (TBL) perturbed by a slender square cylinder. A moderate Reynolds number of Reτ=3691 is considered. The cylinder is immersed in different vertical regions of the TBL, from the viscous sublayer to the logarithmic layer, depending on the value of the cylinder–wall gap ratio within the range of G/D=0.0−2.0. Here, G is the distance between the wall and the lower surface of the cylinder, and D is the cross-section size of the square cylinder. The results reveal a substantial influence of the TBL statistics and structures. Utilizing velocity correlation and proper orthogonal decomposition (POD), we highlight the intriguing influence of large-/very large-scale turbulent structures induced by the cylinder. When the cylinder is positioned on or in close proximity to the wall, periodic shedding of vortices is not apparent. In the presence of a cylinder, the large-/very large-scale turbulent structures are reduced in size compared with those in the undisturbed TBL, owing to the interaction between the flow around the cylinder and the boundary layer turbulence. The lower modes of the POD in the disturbed TBL are similar to those of the undisturbed flow field. However, the large-/very large-scale turbulent structures are increasingly affected by the strengthening of the shedding vortices with increasing G/D when the cylinder is located in the logarithmic region. As a result, the Kármán vortex street becomes the dominant structure associated with the higher POD modes at sufficiently high cylinder–wall gap ratios.
Pressure-induced photo responsiveness enhancement and positive–negative switch in ZrSe2
Authors: Wang Na , Moutaabbid Hicham , Feng Zhenbao , Wang Guangyu , Zhang Haiwa , Zhang Guozhao , Cao Ziyu , Li Yinwei , Liu Cailong
Published: August 2024

ZrSe2, a member of the group-IVB transition metal dichalcogenides, shows favorable performance in optoelectronic applications. Here, the photoelectric properties of ZrSe2 under high pressure have been systematically investigated. At 13.5 GPa, the photocurrent of ZrSe2 increases three orders of magnitude greater than its initial value. Interestingly, above 23.5 GPa, ZrSe2 exhibits a negative photocurrent response, which can be attributed to the photothermal effect caused by pressure-induced metallization. This study demonstrates the critical role of pressure in regulating the optoelectronic properties of layered materials and the potential application of layered ZrSe2 in pressure-responsive optoelectronic devices.
GPU-accelerated on-the-fly nonadiabatic semiclassical dynamics
Authors: Myers Christopher A. , Miyazaki Ken , Trepl Thomas , Isborn Christine M. , Ananth Nandini
Published: August 2024

GPU-accelerated on-the-fly nonadiabatic dynamics is enabled by interfacing the linearized semiclassical dynamics approach with the TeraChem electronic structure program. We describe the computational workflow of the “PySCES” code interface, a Python code for semiclassical dynamics with on-the-fly electronic structure, including parallelization over multiple GPU nodes. We showcase the abilities of this code and present timings for two benchmark systems: fulvene solvated in acetonitrile and a charge transfer system in which a photoexcited zinc-phthalocyanine donor transfers charge to a fullerene acceptor through multiple electronic states on an ultrafast timescale. Our implementation paves the way for an efficient semiclassical approach to model the nonadiabatic excited state dynamics of complex molecules, materials, and condensed phase systems.
Extreme high-temperature effects on optical response of CsPbBr3 perovskite
Authors: Cheng Tao , Cheng Pengpeng , Iqbal Safdar , Zuo Zhiyuan , Liu Linhua , Yang Jia-Yue
Published: August 2024

The temperature sensitivity of CsPbBr3 perovskite impacts the performance of related devices, with their optoelectronic behavior characterized by the dielectric function (ε = ε1+iε2). Yet, research on optical properties (ε) beyond 200 °C remains limited, hindering the evaluation of their high-temperature stability. This study first grew a high-quality CsPbBr3 single crystal, then examined its dielectric function from −55 to 550 °C using spectroscopic ellipsometry, and explored the optical response of all-dielectric CsPbBr3-based metasurfaces under varying temperatures. High temperature induces dynamic disorder in CsPbBr3, and thermal decomposition initiates above 300 °C, leading to a substantial change of dielectric function. CsPbBr3-based metasurfaces exhibit near-perfect light absorption (average 0.987) with only a meta-atomic height equivalent to one-seventh of the wavelength. They also demonstrate enhanced absorption at longer wavelengths, attributed to high-temperature-enhanced magnetic resonance. This work aims to improve the high-temperature performance of CsPbBr3 perovskites and expand their applications in energy and ultrafast optics.
Hybrid integrated GaSb/Si3N4 narrow linewidth (<50 kHz) distributed Bragg reflector laser
Authors: Ojanen Samu-Pekka , Zia Nouman , Viheriälä Jukka , Koivusalo Eero , Hilska Joonas , Quashef Ajwaad , Wallin Anders , Hanhijärvi Kalle , Fordell Thomas , Guina Mircea
Published: August 2024

A narrow linewidth hybrid integrated distributed Bragg reflector (DBR) laser platform operating at 2 μm wavelength region is demonstrated. The laser architecture comprises AlGaInAsSb/GaSb type-I quantum well reflective semiconductor optical amplifiers butt-coupled to a Si3N4 photonic integrated circuit (PIC), incorporating a narrow-band DBR. The DBR is realized with a long spiral-shaped waveguide structure with periodic circular posts placed adjacent to the waveguide. At room temperature operating conditions, the laser exhibits a maximum continuous wave output power of more than 17 mW for emission near 2 μm. Linewidth properties are analyzed with a heterodyne measurement technique, involving the mixing of the laser signal with a frequency comb phase-locked to an ultra-stable laser. The hybrid laser exhibits a narrow linewidth of ∼8 kHz in 1 ms timescale and ∼50 kHz in 10 ms timescale.
Electron tail suppression and effective collisionality due to synchrotron emission and absorption in mildly relativistic plasmas
Authors: Ochs Ian E. , Mlodik Mikhail E. , Fisch Nathaniel J.
Published: August 2024

Synchrotron radiation losses are a significant cause of concern for high-temperature aneutronic fusion reactions such as proton–Boron 11. The fact that radiation losses occur primarily in the high-energy tail, where the radiation itself has a substantial impact on the electron distribution, necessitates a self-consistent approach to modeling the diffusion and drag induced by synchrotron absorption and emission. Furthermore, an accurate model must account for the fact that the radiation emission spectrum is momentum-dependent, and the plasma opacity is frequency-dependent. Here, we present a simple Fokker–Planck operator, built on a newly solved-for blackbody synchrotron diffusion operator, which captures all relevant features of the synchrotron radiation. Focusing on magnetic mirror fusion plasmas, we show that significant suppression of the electron distribution occurs for relativistic values of the perpendicular electron momentum, which therefore emit much less radiation than predicted under the assumption of a Maxwell–Jüttner distribution.
Bouligand–Newton type methods for non-smooth ill-posed problems
Authors: Jin Qinian , Zhang Yun
Published: August 2024

We consider Newton-type methods for solving nonlinear ill-posed inverse problems in Hilbert spaces where the forward operators are not necessarily Gâteaux differentiable. Modifications are proposed with the non-existing Fréchet derivatives replaced by a family of bounded linear operators satisfying suitable properties. These bounded linear operators can be constructed by the Bouligand subderivatives which are defined as limits of Fréchet derivatives of the forward operator in differentiable points. The Bouligand subderivative mapping in general is not continuous unless the forward operator is Gâteaux differentiable which introduces challenges for convergence analysis of the corresponding Bouligand–Newton type methods. In this paper we will show that, under the discrepancy principle, these Bouligand–Newton type methods are iterative regularization methods of optimal order. Numerical results for an inverse problem arising from a non-smooth semi-linear elliptic equation are presented to test the performance of the methods.