bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of the Mediated Learning Observation Instrument Among Children With and Without Developmental Language Disorder in Dynamic Assessment
Authors: Lam Joseph Hin Yan , Resendiz Maria D. , Bedore Lisa M. , Gillam Ronald B. , Peña Elizabeth D.
Published: May 2024

Purpose:

In this validation study, we examined the factor structure of the mediated learning observation (MLO) used during the teaching phase of dynamic assessment. As an indicator of validity, we evaluated whether the MLO factor structure was consistent across children with and without developmental language disorder (DLD).

Method:

Two hundred twenty-four children (188 typically developing and 36 DLD) from kindergarten to second grade completed a 30-min individual mediated learning session on narrative production. Performance during the session was rated using the 12-item MLO by clinicians on affect, behavior, arousal, and elaboration. Exploratory and confirmatory factor analyses were conducted to establish the factor structure and reliability of the MLO.

Results:

Factor analysis of the MLO suggested a stable three-factor model with adequate fit indices across kindergarten and school-age samples, across both typically developing and DLD subgroups with good to excellent reliability. The final 11-item MLO (one item was removed due to low factor loading) comprises three subscales including (a) cognitive factor, (b) learning anticipation, and (c) learning engagement.

Conclusions:

The MLO is a valid and reliable instrument for assessing language learning skills in children with and without DLD during dynamic assessment. Practical implications and suggestions for future research addressing the utilization of MLO in dynamic assessment are provided.
Transcription Decisions of Conjoined Independent Clauses Are Equitable Across Dialects but Impact Measurement Outcomes
Authors: Oetting Janna B. , Maleki Tahmineh
Published: May 2024

Purpose:

Transcription of conjoined independent clauses within language samples varies across professionals. Some transcribe these clauses as two separate utterances, whereas others conjoin them within a single utterance. As an inquiry into equitable practice, we examined rates of conjoined independent clauses produced by children and the impact of separating these clauses within utterances on measures of mean length of utterance (MLU) by a child's English dialect, clinical status, and age.

Method:

The data were archival and included 246 language samples from children classified by their dialect (African American English or Southern White English) and clinical status (developmental language disorder [DLD] or typically developing [TD]), with those in the TD group further classified by their age (4 years [TD4] or 6 years [TD6]).

Results:

Rates of conjoined independent clauses and the impact of these clauses on MLU varied by clinical status (DLD < TD) and age (TD4 < TD6), but not by dialect. Correlations between the rate of conjoined clauses, MLU, and language test scores were also similar across the two dialects.

Conclusions:

Transcription decisions regarding conjoined independent clauses within language samples lead to equitable measurement outcomes across dialects of English. Nevertheless, transcribing conjoined independent clauses as two separate utterances reduces one's ability to detect syntactic differences between children with and without DLD and document syntactic growth as children age.

Supplemental Material:

https://doi.org/10.23641/asha.25822675
Improving pulsar timing precision through superior time-of-arrival creation
Authors: Wang J. , Verbiest J. P. W. , Shaifullah G. M. , Cognard I. , Guillemot L. , Janssen G. H. , Mickaliger M. B. , Possenti A. , Theureau G.
Published: May 2024

Context. The measurement of pulsar pulse times-of-arrival (ToAs) is a crucial step in detecting low-frequency gravitational waves. To determine ToAs, we can use template-matching to compare each observed pulse profile with a standard template. However, using different combinations of templates and template-matching methods (TMMs) without careful consideration can lead to inconsistent results.

Aims. In pulsar timing array (PTA) experiments, distinct ToAs from the same observations can be obtained due to the use of diverse templates and TMMs. In other words, employing diverse approaches can yield different timing results and would thus have a significant impact on subsequent gravitational wave searches. In this paper we examine several commonly used combinations to analyze their effect on pulse ToAs.

Methods. We evaluated the potential impact of template and TMM selection on 13 typical millisecond pulsars within the European PTA. We employed pulsar timing methods, specifically the root mean square and reduced chi-square (χ2r) of the residuals of the best timing solution, to assess the outcomes. Additionally, we evaluated the system-limited noise floor (SLNF) for each pulsar at various telescopes operating around 1.4 GHz using frequency-resolved templates.

Results. Our findings suggest that utilizing data-derived and smoothed templates in conjunction with the Fourier-domain with Markov chain Monte Carlo TMM is generally the most effective approach, though there may be exceptions that require further attention. Furthermore, we determine that pulse phase jitter noise does not significantly limit the current precision of the European PTA’s timing, as jitter levels derived from other studies are much lower than the SLNF.
Stellar angular momentum of intermediate-redshift galaxies in MUSE surveys
Authors: Muñoz López C. , Krajnović D. , Epinat B. , Herrero-Alonso Y. , Urrutia T. , Mercier W. , Bouché N. F. , Boogaard L. A. , Contini T. , Michel-Dansac L. , Pessa I.
Published: May 2024

We quantify the stellar rotation of galaxies by computing the λR parameter, a proxy for the stellar angular momentum in a sample of 106 intermediate-redshift galaxies (0.1 < z < 0.8). The sample is located in the CANDELS/GOODS-S and CANDELS/COSMOS regions, and it was observed by various MUSE surveys. We created spatially resolved stellar velocity and velocity dispersion maps using a full-spectrum fitting technique, covering spatially ∼2Re for the galaxies. The sample spans stellar masses from ∼107.5 M⊙ to 1011.8 M⊙ with star formation rates (SFRs) from log10(SFR)≈ − 3 M⊙ yr−1 to ≈1.7 M⊙ yr−1 over a range of 6 Gyr in cosmic time. We studied how the atmospheric seeing, introduced by the instrumental point spread function (PSF), affects the measured spin parameter, and we applied corrections when pertinent. Through the analysis of the λR − ϵ diagram, we note that the fraction of round and massive galaxies increases with redshift. We did not measure any galaxy with λR < 0.1 in the sample, and we found only one potential (but uncertain) low-mass slow rotator at z ∼ 0.3, more similar to the z = 0 low-mass slow rotators characterized by counter-rotation than to massive ellipticals. Moreover, we do not see an evident evolution or trend in the stellar angular momentum with redshift. We characterized the galaxy environment using two different indicators: a local estimator based on the Voronoi tesselation method, and a global estimator derived by the use of the friends-of-friends (FoF) algorithm. We find no correlation between the environment and λR given that we are not probing dense regions or massive galaxy structures. We also analysed the kinematic maps of the sample finding that about 40% of the galaxies are consistent with being regular rotators (RRs), having rotating stellar discs with flat velocity dispersion maps, while ∼20% have complex velocity maps and can be identified as non-regular rotators in spite of their λR values. For the remaining galaxies the classification is uncertain. As we lack galaxies with λR < 0.1 in the sample, we are not able to identify when galaxies lose their angular momentum and become slow rotators within the surveyed environments, area, and redshift range.
Comparative analysis of hydroclimatic characteristics on the territory of the Amur, Angara-Yenisei and drainage Torey basins (Eastern Transbaikalia)
Authors: Zima Yuri , Matyugina Evgeniya
Published: May 2024

A comparative analysis of hydroclimatic characteristics was carried out on the territory of the Amur, Angara-Yenisei and Torey closed drainage basins of Eastern Transbaikalia. According to monitoring weather stations, high rates of air temperature growth have been established for the territory of the mountain-taiga zone of the Angara-Yenisei basin, where the linear trend was 2.2, while for the arid steppe zone of the Torey endorheic basin – 1.8. The smallest linear trend of 1.5 was identified for the territory of the Amur Basin. In all studied basins, synchronous cyclicity of precipitation and water levels was revealed against the background of their average annual decrease.
Processing of waste (tails) after flotation of copper production slag to obtain iron oxide pigment
Authors: Samadov Alisher , Askarova Nilufar , Toshkodirova Rano , Akhmedova Nigora , Boltayev Olmos , Mirzayev Komiljon , Kambarov Asadjon
Published: May 2024

At this work, the processing of waste after flotation of copper production slag to obtain iron oxide pigment is presented. Based on the results of the experiments, the influence of various factors and parameters on the processing of iron-containing waste (tailings) of the copper concentration plant-2 of the AMMC was studied; This approach is both uncomplicated and efficient for extracting Fe2O3, which is regarded as a primary ingredient in the manufacturing of iron pigment. It was found that when caustic soda is used for alkaline roasting, the iron oxides in the tailings react with nitrates and hydrates to form an insoluble solid phase. Additionally, it was discovered that firing temperatures above 350 °C result in the formation of a sodium aluminate compound. This compound and the iron compounds dissolve in solutions and negatively affect the quality of the resulting Fe2O3 pigment.
Mathematical modeling of unsteady temperature regime of solar pond device
Authors: Elmurodov N.S. , Uzakov G.N. , Kodirov I.N. , Tilavov Yu.S.
Published: May 2024

In the article, the thermal regimes of the layers of experimental solar pond with dimensions of 0.7 m and 1.5 m, height of 1.5 m, built in the training ground of Karshi Engineering Economics Institute, were mathematically modeled based on the climatic conditions of Karshi city. In the dynamic mode of the solar pond device, at a concentration of 25% of pond water, the energy collection efficiency of the layers was calculated analytically for the months of May, June, September and October, 2022. A mathematical model of the temperature changes of the layer over time during the absorption of solar radiation through the depth of the solar pond has been developed. The experimental and model calculation results of this solar pond were compared based on Fisher’s criterion. Among the monthly comparison results for each layer, the closest difference was observed in the LCZ layer, which was 8.8%.
Simulation modeling as a tool for predicting the quality of wastewater treatment in food production
Authors: Semenova T.S. , Didikov A.E. , Sergienko O.I.
Published: May 2024

The possibility of using simulation modeling to predict the quality of wastewater treatment in food production is considered using the example of the baking industry. Using the GPS-X 8.0 software product, the efficiency of wastewater treatment processes at local wastewater treatment plants for the production of bakery products, confectionery products and mixed-type production with the production of bakery products, small baked goods and confectionery production was studied. It is shown that the use of a systematic approach ensures the development of effective local facilities for wastewater treatment.
Influence of water flow on the strength characteristics of rocks of the Lovosersk rare metal deposit
Authors: Kalashnik Anatolii
Published: May 2024

Data on the flow of water into the mine workings of the Karnasurt mine, which mines two concordant ore deposits of the Lovozero rare metal deposit, are considered. Statistical processing of the volumes of water collected by the mine over the past 4 years was carried out, with an assessment of the dynamics during the calendar year. Features associated with calendar climate changes have been identified. The main goal of the work was to assess the influence of water inflows on the strength characteristics of the rocks that make up the supporting pillars. Analysis and calculations of sedimentation within the mining allotment of the mine and the emerging water inflows into the mine workings were carried out, and they were compared with actual data on mine water. Samples of the most representative rocks of the deposit were selected and tested for compressive and tensile strength in dry and water-saturated states. The obtained data are presented in tabular form and in diagrams. Quantitative indicators of changes in the strength characteristics of rocks due to water saturation have been determined. A recommendation is given on the need to take into account the identified dependencies when calculating the stability of both supporting pillars and rock outcrops in the workings of the Karnasurt mine, which are subject to abundant water wetting.
Changes in the properties of clay soil in drained and undrained conditions under the influence of cathodic protection currents
Authors: Burlutsky S.B. , Evenkova T.D. , Lazdovskaya M.A. , Dubrova S.V. , Zelenkovskiy P.S.
Published: May 2024

This work examines the influence of cathodic protection currents on the properties of clay soil under drained and undrained conditions. The study was carried out using an experimental setup simulating cathodic protection. At the end of the experiment, soils with an undisturbed structure near the cathode were studied, where changes in the physical properties, particle size distribution and pH of polarized clay soil samples were revealed.
Methodology for predicting the specific effectiveness of geological and technological measures aimed at increasing the coefficient of reservoir coverage by flooding
Authors: Gilyazetdinov Ruslan , Voblikova Elizaveta , Sharipov Farit , Samigullina Lilia , Kobishcha Dina
Published: May 2024

Recently, there has been a tendency in the Russian Federation to reduce the design values of oil recovery, the main parameter characterizing the rationality of field development. In many ways, the decrease in question is due to the development of the most productive deposits discovered back in Soviet times. To maintain production levels in mature fields, it is necessary to apply various methods of increasing oil recovery (MIOR). According to many experts, one of the most effective ways to increase oil recovery are methods aimed at increasing the reservoir coverage ratio and displacement coefficient by pumping various chemical compositions into the productive reservoir. Thus, when using various physico-chemical methods of enhanced oil recovery (PCMOR), it is necessary to conduct preliminary assessments of their effectiveness. Due to the comprehensive analysis of field data on several fields in Western Siberia, the main geological and technological parameters that most affect the effectiveness of the measures are highlighted in the work. Based on the selected characteristics, using geological and statistical modeling, a methodology for predicting the specific effect of PCMOR MIOR treatments has been developed.
Digital support and evaluation of the effectiveness of geological and technical measures based on artificial intelligence systems
Authors: Gilyazetdinov Ruslan
Published: May 2024

In this paper, the authors present the approbation of an artificial intelligence algorithm for digital support and evaluation of the effectiveness of the implementation of geological and technical measures in various mining and geological conditions. The object of the study was the deposits of deposit N, characterized by significant variability of parameters reflecting the filtration and capacitance properties of productive formations and their saturating fluids. With the help of the created system, maintenance of repair and insulation works at one of the wells of the object under study was successfully carried out. The presented main stages of the algorithm are universal and can be used in other fields to solve a wide range of problems in the development of deposits. The conclusion is made about the prospects of the direction «digitalization in oil production» and the relevance of the development of this topic in the context of the need to increase the pace of extraction of reserves.
Analysis of the causes of flooding of long-term deposits under conditions of high geological heterogeneity
Authors: Gilyazetdinov Ruslan , Vafin Rif , Kuleshova Lyubov , Mukhametshin Vyacheslav V.
Published: May 2024

In this work, the object of research was the long-term deposits of liquid hydrocarbons located within the boundaries of fields with high geological heterogeneity, the proportion of which is actively increasing every year due to the selection of a significant part of the “light” oil reserves. Based on the generalization of the results of direct and indirect research on the topic of the work, the key causes of well flooding were identified and their primary sources were identified, which made it possible to successfully describe the mechanisms of formation of the transition zone of the oil-water system, depending on the stage of development. The conclusion is made about the importance of applying relevant and reliable scientific and methodological approaches in interpreting the results of geophysical research to solve various problems of oil field development.
An explicit well-balanced scheme on staggered grids for barotropic Euler equations
Authors: Goudon Thierry , Minjeaud Sebastian
Published: May 2024

In this paper, we introduce a specific modification of the numerical fluxes in order to insure the well-balanced property of schemes on staggered grids for the Euler equations. This property is crucial for the numerical representation of equilibrium solutions of balance laws with source terms, like when describing flows subjected to gravity and a complex topography. We propose first and second order versions of the well-balanced scheme. The performances of the method are evaluated through a series of 1D and 2D benchmarks.
Temps et espace intimes dans la construction de récits au cours d’un atelier d’écriture à vocation thérapeutique
Authors: Demolliens Laetitia , Kobylanski Anne
Published: May 2024

L’approche phénoméno-structurale a déjà démontré son intérêt au sein de nombreux champs d’application de la pratique psychologique. Nous souhaitons ici apporter une illustration de son déploiement actuel dans le cadre d’un atelier d’écriture à vocation thérapeutique mené en hôpital général et regroupant des patients de divers horizons. Proposer une ouverture sur l’expression de l’imaginaire par le biais de l’écriture permet une décentration du symptôme favorisant l’expression même de la structure de personnalité et donc une mise en avant de ses fragilités comme de ses ressources. La séance présentée ici s’appuie sur deux textes qui renvoient à deux personnalités différentes qui pourtant se répondent en écho. Nous analyserons par le biais d’une étude fine du langage et de l’expression les mouvements psychiques à l’œuvre et leur déploiement au fil du texte, afin d’en dégager des tendances globales de structure de personnalité. Les appuis spatio-temporels, les mécanismes essentiels du lien et de la coupure et enfin le conflit psychique seront ainsi explorés au plus près de la réalité vécue des personnes.
La complexité au fondement de la pédopsychiatrie
Authors: Tandonnet Louis
Published: May 2024

Aujourd’hui la pédopsychiatrie apparaît comme un champ d’opposition entre différents rationalismes scientifiques. S’y ajoute une défiance croissante envers la subjectivité des cliniciens et plus largement envers leur « appareil sémiologique » c’est à dire tout l’édifice institutionnel, de pratique et de pensée qui les entoure. Historiquement, cette remise en question du raisonnement médical renvoie à un débat ancien qui traverse l’ensemble de la Médecine depuis les Lumières. Pour y répondre, la pédopsychiatrie, consciente de la complexité de son objet d’intérêt – les phénomènes mentaux, le développement, la personne humaine, la société – a construit un « appareil sémiologique » susceptible d’appréhender cette complexité. Il associe éclectisme pluridisciplinaire, appréhension dynamique des trajectoires bio-psycho-sociales et soucis de la rencontre clinique. Nous articulerons ces éléments avec trois principes qui décrivent les objets complexes.
A systematic synthesis and analysis of English-language Shuōwén scholarship
Authors: Qin Melissa Xiaohui
Published: May 2024

This study documents the past and present of English scholarship of Shuōwén jiězì, the most important masterpiece of classical Chinese philology and lexicography. In an attempt to investigate the current status (synchronically) and developmental trajectory (diachronically) of Shuōwén scholarship, this study surveyed the bibliographical, theoretical, methodological and thematic state of Shuōwén literature manifested in an analytical framework of six parameters (geographic distribution, publication outlets, citations, theoretical approaches, research methods and research strands) by adopting a thorough bibliometric analysis subsequent to meticulous coding in terms of these six parameters in Shuōwén scholarship. The results showed that Shuōwén scholarship has displayed distinctive distribution patterns and chronological trends along bibliographical, theoretical, methodological and thematic dimensions. Synchronically, the research output is regionally based, thematically restricted and qualitatively examined; diachronically, the research quality is fluctuating, though research quantity multiplies steadily. To look ahead, the study sketched a few directions for advancement of future research agendas: a more global profile of researchers, a larger degree of internationalization of the native circle, a wider disciplinary range, and increased specialization streamlined into data-driven approach to core issues of liùshū, bùshǒu and GPS (graphic-phonetic-semantic) of head graphs. The study is useful in portraying an overarching disciplinary landscape for Shuōwén research and providing the basic reference statistics for possible comparisons across classical Chinese studies and for more general conclusions about the state of scholarship on sinology.
Navigating the nexus: unraveling technological innovation, economic growth, trade openness, ICT, and CO2 emissions through symmetric and asymmetric analysis
Authors: Junsheng Ha , Mu Yuning , Masud Muhammad Mehedi , Akhtar Rulia , Saif Abu Naser Mohammad , Islam K. M. Anwarul , Hafiz Nusrat
Published: May 2024

In Malaysia’s rapid economic growth and industrialization, environmental degradation and carbon emissions pose significant challenges. As urbanization continues to rise, there is a growing recognition of the imperative to tackle CO2 emissions. Trade openness and globalization drive economic activity but also heighten environmental pressures, including CO2 emissions from transportation and industry. Information communication technology (ICT) usage, shaped by infrastructure and regulations, can either improve energy efficiency or increase energy consumption. The study examines the impacts of economic growth (EG), trade openness (TON), technological innovation (TIN), and ICT on CO2 emissions in Malaysia, using both symmetric and asymmetric methods from 1985 to 2021. While many studies have explored environmental degradation, focusing on CO2 emissions and ecological footprint indicators, only a limited number have delved into the combined impact of sustainable EG, TON, ICT, and TIN on Malaysia’s CO2 emissions. Notably, these studies have often neglected the utilization of both symmetric and asymmetric methodologies. Hence, this study employed auto-regressive distributed lag (ARDL) and non-linear ARDL approaches to investigate the dynamic effects of the studied variables. The key findings from the symmetric analysis demonstrate that EG, TON, and ICT together take part in the increase of CO2 emissions in both the short and long run. Particularly, technological innovation plays a significant role in reducing CO2 emissions in the short term through the adoption of cleaner technologies. However, the results of the NARDL bound test reveal asymmetric long-term consequences of technological innovation, economic growth, and ICT on CO2 emissions. The study underscores the need for CO2 reduction policies in Malaysia, advocating for measures, such as incentivizing cleaner technologies and upgrading energy infrastructure. It also recommends implementing carbon pricing mechanisms for production and trade, alongside awareness campaigns to foster behavioral changes aimed at reducing emissions.
Keeping balance between loyalty and modification: a Toulminian model as analytical framework
Authors: Liu Donghong , Xiong Minghui
Published: May 2024

Toulmin model has been widely applied to composition-rhetoric and several modified models have been advanced. However, those modified versions diverge widely from Toulmin model. To Keep loyalty to Toulmin’s argumentation and infuse van Eemeren et al.’s pragma-dialectic view, we propose a new modified model as an analytical framework for argumentative essays, with the assumption that a writer is in fact arguing with a potential reader who holds a different view. The proposed framework was applied to explore the Chinese writers’ argumentative essays with content analysis employed. Altogether 60 essays were selected, coded, and analyzed. The results show that the Chinese writers preferred parallel arguments (i.e., several arguments supporting the same claim with the same ground-warrant structure) to hierarchical ones, justification to opposition, and descriptive warrant to the other types. Moreover, the adult expert writers wrote more warrants and qualifiers than the novice writers. The results reveal Chinese rhetoric and writing conventions, and prove the effectiveness of our proposed analytical framework.
Kinetics of the thermal decomposition of thermally reduced graphene oxide treated with a pulsed high-frequency discharge in hydrogen atmosphere
Authors: Barabashko M. S. , Drozd M. , Dolbin A. V. , Basnukaeva R. M. , Vinnikov N. A.
Published: May 2024

Thermal stability and the kinetics of thermal decomposition of the thermally reduced graphene oxide (TRGO) treated by a pulsed high-frequency discharge in a hydrogen atmosphere have been studied. The modified Hummers method was used for obtaining the initial graphite oxide from graphite powder. Thermal exfoliation of the graphene oxide powder has been done in vacuum conditions with a heating rate of 5–7 degrees per minute to a temperature of 300 °С. TRGO has been treated by pulsed high-frequency discharge in a hydrogen atmosphere for partial graphene hydrogenation (chemical addition of atomic hydrogen) that leads to structural changes in the carbon planes and formation of C–H sp3 bonds. The thermogravimetry analysis measurements of the mass loss have been carried from room temperature to 1000 °C in a nitrogen atmosphere with a nitrogen flow rate of 20 mL/min and different heating rates: 50, 75 100, 125, 150, and 200 K/min, respectively. Kissinger’s multiple heating rate method has been used to determine the activation energy for decomposing substances. Activation energies Ea1, Ea2, and Ea3 equal 28, 50, and 148 kJ/mol, respectively, have been compared with the energies of the activation of thermal defunctionalization of multiwalled carbon nanotubes (MWCNTs). The activation energy Ea3 = 148 kJ/mol is close to that of the thermal decomposition of anhydride functional groups in MWCNT. The value of Ea2 = 50 kJ/mol indicates the presence of the keto and hydroxy acid’s function groups on TRGO. Activation energy Ea1 = 28 kJ/mol related with all other groups including the lighter C–H bonds that destructed due to dehydrogenation of the TRGO. Obtained experimental results are useful for further proposing the kinetic model of the mechanism of the most probable reaction of TRGO decomposition.
Manifestation of the Aharonov–Bohm effect in hydrodynamic instability of an electron beam moving along a semiconductor nanotube
Authors: Averkov Yu. O. , Prokopenko Yu. V. , Yampol’skii V. A.
Published: May 2024

We theoretically study a manifestation of the Aharonov–Bohm effect in hydrodynamic instability of a tubular nonrelativistic electron beam moving along a semiconductor nanotube with dielectric filling placed in a coaxial dc magnetic field. The calculations are performed with taking into account the retardation effect for electromagnetic fields. The dispersion equation for the coupled waves of the structure under study and the electron beam, as well as the expression for the increment of the hydrodynamic instability have been derived and numerically analyzed. The mechanism of nonlinear stabilization of the hybrid bulk-surface and surface electromagnetic waves is studied by the method of slowly varying in time amplitudes and phases. The physical cause of excitation of such waves is the Cherenkov resonance, and the nonlinear stabilization mechanism is based on the trapping of beam particles by the field of the excited wave. The numerical analysis shows that the time of saturation of the instability and the maximum field amplitudes depend on the number of magnetic flux quanta in the nanotube and changes with the period equal to one magnetic flux quantum. These dependences are the result of the Aharonov–Bohm effect.
High detectivity, near-infrared organic printed photodiode
Authors: Jan Jasmine , Vogliano Anthony , Ahmed Maruf , Babics Maxime , McCulloch Iain , Arias Ana C. , Toor Anju
Published: May 2024

Sensitive detection of near-infrared (NIR) light could enable several important applications in optical communications, quality control, and sensing in industries, such as automotive and aerospace, and human–machine interface (HMI) biometrics. In this work, we demonstrate NIR photodetectors based on an organic bulk heterojunction absorbing layer with state-of-the-art performance across critical response metrics. The external quantum efficiency spectrum of the devices presented extends from 500 nm to approximately 900 nm covering both visible and NIR wavelengths. The organic photodiodes (OPDs) show specific detectivities of around 7.4×1011 Jones, which is comparable to the state of the art organic devices. Furthermore, the NIR OPD devices show a linear dynamic range (LDR) of ∼74 dB.
Photoluminescence studies of the charge states of nitrogen vacancy centers in diamond after arsenic ion implantation and subsequent annealing
Authors: Huangfu Chenyang , Zhang Yufei , Hao Jinchen , Jia Gangyuan , Wu Haitao , Wang Xujie , Wang Wei , Wang Kaiyue
Published: May 2024

In this work, nitrogen vacancy (NV) centers of high nitrogen diamond implanted with arsenic ions were investigated by photoluminescence spectroscopy. The transition of the NV center charge state was discussed by the regularly changing laser excitation power and measurement temperature following high-temperature annealing. After high-temperature annealing, the amorphous layer generated by arsenic ion implantation is transformed into a graphitization layer, resulting in a decrease in the NV yield. The electric neutral NV (NV0) center and negatively charged NV (NV−) center are affected by both radiation recombination and Auger recombination with increasing laser power. Accompanied by the increasing measurement temperature, the intensities of NV centers gradually decreased and eventually quenched. In addition, the charge states of NV− and NV0 centers were undergoing a transition. The zero phonon line positions of NV centers were also red shift, it was attributed to the dominant role of electron–phonon interaction in the temperature-dependent displacement of diamond energy gaps. The full width at half maxima of NV center were broadened significantly at higher temperatures.
Investigation and development of programmable system on chip based differential scanning calorimeter for thermal analysis of materials
Authors: Keshari Ajay Kumar , Rao J. Prabhakar , Ganesan Rajesh
Published: May 2024

A differential scanning calorimeter was designed to study the thermal analysis of the materials for the nuclear reactor/allied facilities. The hardware and software were developed for measuring the calorimetric signals and had various features for the thermal analysis of the material. The processing of calorimetric signals was carried out by a programmable system-on-chip. Using a programmed temperature profile, the differential scanning calorimeter setup was tested, calibrated, and validated with standard aluminum and indium metal samples. It was found that the obtained results agree with the literature values. The methodology for the experiment was optimized. Various experiments were carried out, and the thermal analysis of different materials for nuclear reactors was investigated and studied. The instrumentation is also compact, accurate, reliable, and cost-effective for the thermal analysis of materials.
Enhancing ferroelectric characterization at nanoscale: A comprehensive approach for data processing in spectroscopic piezoresponse force microscopy
Authors: Valloire H. , Quéméré P. , Vaxelaire N. , Kuentz H. , Le Rhun G. , Borowik Ł.
Published: May 2024

Switching Spectroscopy Piezoresponse Force Microscopy (SSPFM) stands out as a powerful method for probing ferroelectric properties within materials subjected to incremental polarization induced by an external electric field. However, the dense data processing linked to this technique is a critical factor influencing the quality of obtained results. Furthermore, meticulous exploration of various artifacts, such as electrostatics, which may considerably influence the signal, is a key factor in obtaining quantitative results. In this paper, we present a global methodology for SSPFM data processing, accessible in open-source with a user-friendly Python application called PySSPFM. A ferroelectric thin film sample of potassium sodium niobate has been probed to illustrate the different aspects of our methodology. Our approach enables the reconstruction of hysteresis nano-loops by determining the PR as a function of applied electric field. These hysteresis loops are then fitted to extract characteristic parameters that serve as measures of the ferroelectric properties of the sample. Various artifact decorrelation methods are employed to enhance measurement accuracy, and additional material properties can be assessed. Performing this procedure on a grid of points across the surface of the sample enables the creation of spatial maps. Furthermore, different techniques have been proposed to facilitate post-treatment analysis, incorporating algorithms for machine learning (K-means), phase separation, and mapping cross correlation, among others. Additionally, PySSPFM enables a more in-depth investigation of the material by studying the nanomechanical properties during poling, through the measurement of the resonance properties of the cantilever–tip–sample surface system.
Analysis of reducing thermal resistance between the PCM and ambient air for improving the power generation characteristics of PCM-based thermoelectric power generators
Authors: Suemori Kouji , Komazaki Yusuke , Fukuda Nobuko
Published: May 2024

A power generator comprising a thermoelectric device (TED) and a phase change material (PCM) allows energy harvesting from ambient temperature variations, which exist ubiquitously; thus, such a device has received considerable attention as an energy harvester that can operate at any location. We developed a model for estimating the characteristics of a power generator in ambient air, whose temperature is forcibly changed between two temperature values, such as when an air conditioner is turned on and off. We calculated the influence of latent heat and thermal conductivity of the PCM on the characteristics of power generators with various thermal resistances between the TED/PCM interface and ambient air. Latent heat and thermal conductivity of the PCM affect the amount of heat energy (Q) transfer between the ambient air and PCM and the energy conversion efficiency (ηE), respectively, where the amount of electric energy is given by Q × ηE. The increase in Q caused by an increase in the latent heat of the PCM was almost independent of the thermal resistance between the TED/PCM interface and air. However, the increase in ηE caused by an increase in the thermal conductivity of the PCM decreased as the thermal resistance between the TED/PCM interface and air increased. These results indicate that the techniques to improve the power generation characteristics by increasing the thermal conductivity of PCM, which have been frequently investigated in recent years, are effective only when the thermal resistance between the TED/PCM interface and ambient air is small.
Imaging spatial plasmon mode of nanocavity formed by Au tip and Au nanorod lattice in tip-enhanced Raman spectroscopy
Authors: He Zhe , Wang Jue , Wang Rui , Kurouski Dmitry
Published: May 2024

The integration of Au nanorods in tip-enhanced Raman spectroscopy (TERS) presents a significant increase in the enhancement factor, primarily due to the gap-mode effect. By aligning Au nanorods in parallel, we construct an Au nanorod lattice, referred to as the Au nanolattice, which further amplifies the advantages of TERS imaging due to the induced inter-nanorod surface plasmon resonance. A critical aspect in this research involves investigating the distribution of hotspots within the nanolattice during TERS measurements. Additionally, we demonstrate that the tip–lattice nanocavity is a predominant factor in determining both the intensity and spatial distribution of these hotspots. Employing the experimental and simulation results, we illustrate the enhancement effect of the tip–lattice cavity and elucidate the connection between the hotspot intensity and cavity size. This comprehensive approach contributes to our understanding of the nano-lattice’s role in TERS and offers valuable insights for optimizing nanophotonic applications.
Investigation of ultrafast intermediate states during singlet fission in lycopene H-aggregate using femtosecond stimulated Raman spectroscopy
Authors: Peng Bo , Wang Ziyu , Jiang Jiaming , Huang Yifan , Liu Weimin
Published: May 2024

The singlet fission process involves the conversion of one singlet excited state into two triplet states, which has significant potential for enhancing the energy utilization efficiency of solar cells. Carotenoid, a typical π conjugated chromophore, exhibits specific aggregate morphologies known to display singlet fission behavior. In this study, we investigate the singlet fission process in lycopene H-aggregates using femtosecond stimulated Raman spectroscopy aided by quantum chemical calculation. The experimental results reveal two reaction pathways that effectively relax the S2 (11Bu+) state populations in lycopene H-aggregates: a monomer-like singlet excited state relaxation pathway through S2 (11Bu+) → 11Bu− → S1 (21Ag−) and a dominant sequential singlet fission reaction pathway involving the S2 (11Bu+) state, followed by S* state, a triplet pair state [1(TT)], eventually leading to a long lifetime triplet state T1. Importantly, the presence of both anionic and cationic fingerprint Raman peaks in the S* state is indicative of a substantial charge-transfer character.
Mid-infrared optical coherence tomography with MHz axial line rate for real-time non-destructive testing
Authors: Yagi Satoko , Nakamura Takuma , Hashimoto Kazuki , Kawano Shotaro , Ideguchi Takuro
Published: May 2024

Non-destructive testing (NDT) is crucial for ensuring product quality and safety across various industries. Conventional methods, such as ultrasonic, terahertz, and x-ray imaging, have limitations in terms of probe-contact requirement, depth resolution, or radiation risks. Optical coherence tomography (OCT) is a promising alternative to solve these limitations, but it suffers from strong scattering, limiting its penetration depth. Recently, OCT in the mid-infrared (MIR) spectral region has attracted attention with a significantly lower scattering rate than in the near-infrared region. However, the highest reported A-scan rate of MIR-OCT has been 3 kHz, which requires long data acquisition time to take an image, unsatisfying industrial demands for real-time diagnosis. Here, we present a high-speed MIR-OCT system operating in the 3–4 µm region that employs the frequency-swept spectrum detection in OCT technique based on time-stretch infrared spectroscopy. By integrating a broadband femtosecond MIR pulsed laser operating at a repetition rate of 50 MHz, we achieved an A-scan rate of 1 MHz with an axial resolution of 11.6 µm, a 10 dB roll-off depth of about 700 µm, and a sensitivity of 55 dB. As a proof-of-concept demonstration, we imaged the surface of substrates covered by highly scattering paint coatings. The demonstrated A-scan rate surpasses previous state of the art by more than two orders of magnitude, paving the way for real-time NDT of industrial products, cultural assets, and structures.
Numerical and experimental study of supersonically expanding argon plasma using a micrometer hollow cathode discharge
Authors: Gu Yu , Suas-David Nicolas , Bouwman Jordy , Li Yongdong , Linnartz Harold
Published: May 2024

Pulsed discharge nozzles (PDNs) have been successfully used for decades to produce rotationally cold (Trot ∼ 20 K) radicals and ions of astrophysical interest and to characterize these species spectroscopically. In this work, an evolution of the PDN, the piezostack pulsed discharge nozzle (P2DN), is used for the first time to investigate the characteristics of the still poorly understood supersonic plasma expansion. The P2DN allows for a better control of the reservoir pressure of which an accurate measurement is required to characterize the plasma expansion. This new source, thus, gives the opportunity to further optimize the plasma conditions and extend its use to new target species. The spatial distribution of an argon plasma and the effect of the supersonic flow for different pressures are studied by combining a two-dimensional extended fluid model (extFM) and a direct simulation Monte Carlo (DSMC) method. The combined simulation is validated with experimental results obtained through emission spectroscopy associated with a group-code collisional-radiative model to retrieve the plasma parameters. The validated numerical approach (DSMC-extFM) allows for an accurate characterization of the plasma structure in our typical experimental conditions (a reservoir pressure ranging from 90 to 905 mbar). Thus, this simulation will be used in future studies to improve the plasma conditions to favor the synthesis of (transient) hydrocarbon species as found in space, by seeding the argon gas with a suitable precursor, such as acetylene.
Dynamics of microdroplet generation via drop impact on a superhydrophobic micropore
Authors: Reza Mohammad Shibli , Ko Young-Su , Jeon Byeong Eun , Sen Prosenjit , Lee Choongyeop
Published: May 2024

This study delves into the dynamics of generating microdroplets by impacting a droplet onto a micropore on superhydrophobic copper substrates. It identifies the necessary impact velocities for single microdroplet formation for each micropore and characterizes microdroplet size in relation to micropore diameter. The results underscore the significant role of viscosity, especially as the diameter of the micropore decreases. For micropores measuring 400 μm, an increase in viscosity up to 8 cP does not alter the critical impact velocities, while smaller diameters of 50 and 100 μm see a notable change in critical velocities with even minor increases in viscosity. Remarkably, the diameter of the microdroplet remains consistent regardless of changes in the liquid viscosity or impact velocity. This research showcases two practical uses of single microdroplets: printing on paper and fabricating microbeads. The insights gained from these findings pave the way for advancements in printing technology and microfabrication techniques.
Influence of image forces on charge–dipole interaction in two-layered systems
Authors: Gabovich Alexander M. , Gorshkov Vyacheslav N. , Semeniuk Valerii F. , Voitenko Alexander I.
Published: May 2024

Interaction between a fixed point electric charge Q and a freely rotating point electric dipole with the magnitude P pinned near a plane interface between two dispersionless insulators with different dielectric permittivities ɛ1 and ɛ2 has been considered. It was shown that, as a result of this interaction and the interaction of the dipole with the polarization charges induced at the interface by the charge Q and the dipole itself, there arise regions where the dipole can possess either one or two equilibrium orientations. The spatial distributions of the electrostatic dipole energy Wtotal under the combined action of the charge Q and the induced interface polarization charges, as well as the equilibrium dipole orientations (orientation maps), the boundaries between the regions with different numbers of dipole orientations, and their evolution with the variation of problem parameters (the charge and dipole magnitudes, the mismatch between ɛ1 and ɛ2, and the charge–interface distance) were calculated. It was shown that there can emerge local minima of Wtotal, which may play the role of traps for dipoles (in particular, excitons in layered structures), and the corresponding requirements for the problem parameters were found. Most results were obtained in analytical form. The model can be applied to various physical systems, for instance, polar molecules, excitons, and trions in layered structures.
The convergence of public sphere and state advocacy
Authors: Li Xi
Published: May 2024

In 2021, China’s entertainment industry experienced a series of unusual argumentative controversies followed by
the creation of the Qing Lang movement initiated by the Chinese government that called for tackling irregularities in the
industry. With strong support from the Chinese public, the Qing Lang movement presents an intriguing case to examine a new model
of social argument representing both the public and state interest in resolving social problems in the Chinese version of the
public sphere. The paper identifies key characteristics defining a reciprocal model of social activism in state-sponsored actions
in China exemplified by the Qing Lang movement. The paper also argues for the value of a culture-specific approach to
understanding public sphere and social activism and clarifies the function of argument in Chinese society.
Capturing the situated, dynamic nature of EMI-lecture listening comprehension in real time
Authors: Ducker Nathan
Published: May 2024

English-medium instruction (EMI) potentially offers pedagogical efficiency by simultaneously providing access to
academic content and English affordances. EMI’s efficacy and effectiveness, however, remain unproven with questions concerning
students’ language proficiency unresolved. As listening to lectures holds a central role in tertiary education and the development
of language skills is founded on second-language listening ability, key concerns for stakeholders are knowing how much of an EMI
lecture students can understand and what factors impact their lecture listening comprehension. Current methodologies used to
capture listening comprehension data, such as tests, surveys, summaries, and transcript markings do not capture the idiosyncratic,
volatile, and multifaceted reactions to aural text phenomena that learners encounter during a lecture. This study, therefore, uses
an innovative foot switch mechanism to capture comprehension data in real time as students participated in an EMI lecture. These
data were then used to guide a stimulated recall. The data showed learners failing to comprehend extensive sections of the lecture
while deeper analysis identified sections of the lecture where issues concerning prior taught knowledge, top-down schema building,
lexical, and bottom-up identification of sounds coincided for multiple learners. Extrapolating from these points of convergence,
pedagogical recommendations are provided.