Quantitative Description Research Articles

Quantitative assessment methods and qualitative evaluation system for the complementary characteristics of multi-energy

Assessing and analyzing the complementary characteristics of renewable energy (RE) is crucial for designing, operating, and optimizing multi-energy complementary systems (MECSs). However, unified and precise quantitative descriptions of the complementary and stability characteristics among various energy outputs in MECSs have lacked attention and research. Here, this study innovatively proposed a mathematical model for the multi-energy complementarity index (MECI), which considers the complementarity rates of multiple energy outputs during zero and non-zero output periods, and a mathematical model for the multi-energy volatility index (MEVI), which accounts for fluctuation thresholds and the overall volatility of output processes. An evaluation system for multi-energy complementarity characteristics qualitative analysis has been established. The natural output processes of RE at three MECSs in China were applied in the case calculations and verification. Results show that the hydropower rated discharge (Qrating) has a significant negative correlation with MECI, with the MECI decreasing by an average of 0.0046 for every 5 m³/s increase in Qrating. The relationship between the Qrating and MEVI shows an overall negative correlation with local fluctuations. Notably, The MECI of the BeiPan River MECSs exhibits significant seasonal characteristics, with the MEVI in summer (0.378) and autumn (0.395) higher than those in spring (0.132) and winter (0.160), closely related to the natural seasonal variations of the three energy sources: water, wind, and solar. We believe that the study can assist in evaluating and making decisions on the multi-energy complementarity characteristics of RE bases in the future, making a significant contribution to achieving dual carbon goals.

Photodetachment photoelectron spectroscopy shows isomer-specific proton-coupled electron transfer reactions in phenolic nitrate complexes

The oxidation of phenolic compounds is one of the most important reactions prevalent in various biological processes, often explicitly coupled with proton transfers (PTs). Quantitative descriptions and molecular-level understanding of these proton-coupled electron transfer (PCET) reactions have been challenging. This work reports a direct observation of PCET in photodetachment (PD) photoelectron spectroscopy (PES) of hydrogen-bonded phenolic (ArOH) nitrate (NO3−) complexes, in which a much slower rising edge provides a spectroscopic signature to evidence PCET. Electronic structure calculations unveil the PCET processes to be isomer-specific, occurred only in those with their HOMOs localized on ArOH, leading to charge-separated transient states ArOH•+·NO3− triggered by ionizing phenols while simultaneously promoting PT from ArOH•+ to NO3−. Importantly, this study showcases that gas-phase PD-PES is a generic means enabling to identify PCET reactions with explicit structural and binding information.

(Invited) Minimizing or Maximizing Contact Effects in Organic Electronics

Contact resistance is an umbrella term capturing various current-limiting mechanisms existing at and around metal/semiconductor junctions of an electronic device. Despite its known detrimental impact on the performance of organic, oxide, and 2D semiconductor electronics, a quantitative and predictive description of contact resistance is still lacking. At the same time, recent evidences show that contact resistance can actually provide benefits to certain applications, thus challenging our common belief. This presentation will clarify why contact issues are so critical to the operation of general thin-film systems, and highlight our recent results on re-defining the role of contact resistance in organic diodes and transistors.

Performance of bolted steel laminated bamboo lumber connections under axial cyclic loading

Bolted connections are well known for their simplistic design and installation, and have been used in bare frame structures of various types of materials including steel and timber. Compared with monotonic loading, cyclic loading is more dangerous. Bamboo has excellent toughness and deformation recovery ability but a quantitative description of the mechanical performance of bolted steel laminated bamboo lumber (LBL) connections under cyclic loading has not yet been determined. As a result, tension and compression tests were carried out separately under axial cyclic loading. Obtained experimental results indicated that the tensile specimens suffer brittle failure because of the premature cracking of LBL due to cyclic loading; the bolts remained almost straight after failure. On the other hand, cyclic compressive specimens showed considerable ductile behavior as the bolts underwent plastic deformation since LBL sustained considerable load prior to failure due. Key mechanical connection parameters such as elastic stiffness, yield and ultimate displacement, yield and ultimate load, ductility ratio obtained from the skeleton curves were carefully analyzed to study the influence of bolt number on various properties. The increase in elastic stiffness from two to four bolts is about 60 % for the cyclic tension specimens, whilst that was about 25 % for the cyclic compression specimens. Compared with the cyclic tensile specimens, cyclic compressive specimens have higher ductility ratio, which is mostly greater than 2. In addition, theoretical models for both loading and unloading curves have been proposed, which showed good agreement with test results.

New Insights into the ORR Catalysis on Pt Alloy Nanoparticles from an Element Specific d-Band Analysis.

Bolstered by their unique atomic structures and tailored compositions, nanoalloys exhibit extraordinary properties making them ideal materials to solve challenges in energy storage and conversion catalysis. However, a quantitative description of the structure-property relationships using an accurate descriptor-based model for nanoalloys, ranging from bimetallic to multimetallic compositions, is needed to drive efficient material design toward high-performance catalysis. In this work, we highlight the electronic property and catalytic activity relationship from an element specific d-band analysis of Pt-based alloy catalysts using X-ray absorption near-edge spectroscopy (XANES). Using a series of L10-MPt/Pt (M = Fe, Co, Ni) core/shell alloy catalysts with well-defined atomic structures, we quantified subtle differences in the Pt d-electron states and correlated the Pt d-band structure to their superior catalytic activity toward the oxygen reduction reaction (ORR). Our analysis used the upper d-band edge position as a predictive descriptor for the mass activity toward the ORR instead of the commonly used d-band center position. Together with density functional theory calculations and Nørskov d-band theory, the upper d-band edge position for the Pt states, derived from experimental measurements, elucidates new physical insights into the ORR performance of the L10-MPt/Pt core/shell catalysts. An element specific Pt d-band analysis using XANES overcomes challenges in traditional X-ray photoelectron spectroscopy-based valence d-band analysis, which cannot distinguish signals from independent elements in nanoalloys. Thus, the insights from the element specific d-band analysis presented in this work are a promising approach to determine structure-property relationships in a variety of transition metal nanoalloys and will be useful in the design of future high-performance catalysts.

Lithium-Ion Transport Properties in DMSO and TEGDME: Exploring the Influence of Solvation through Molecular Dynamics and Experiments.

This study explores the properties of aprotic electrolytes via the application of experimental methods, including nuclear magnetic resonance spectroscopy and electrochemical techniques, along with molecular dynamic modeling. The aim is to provide a quantitative description of the physico-chemical properties of two well-established electrolytes (case studies), each exhibiting significantly distinct dielectric properties: a LiTFSI (Lithium bis(trifluoromethanesulfonyl)imide) solution in dimethyl sulfoxide (DMSO, dielectric constant =46.68) and a LiTFSI solution in tetraethylene glycol dimethyl ether (TEGDME, =7.71). We obtained a comprehensive insight into the properties of the electrolytes at both the macroscopic-collective and molecular levels with particular emphasis on the interactions between the Li ions and solvent molecules. We discovered remarkable disparities in the structural arrangements, solvation behaviors, and bulk-related properties of these electrolyte systems, particularly in response to temperature changes.

Resonant switching current detector based on underdamped Josephson junctions

Current-biased Josephson junctions can act as detectors of electromagnetic radiation. At optimal conditions, their sensitivity is limited by fluctuations causing stochastic switching from the superconducting to the resistive state. This work provides a quantitative description of a stochastic switching current detector, based on an underdamped Josephson junction. It is shown that activation of a Josephson plasma resonance can greatly enhance the detector responsivity in proportion to the quality factor of the junction. The ways of tuning the detector for achieving optimal operation are discussed. For realistic parameters of Nb/AlOx/Nb tunnel junctions, the sensitivity and noise-equivalent power (NEP) can reach values of S≃5×1012 (V/W) and NEP≃2×10−23 (WHz−1/2), respectively. These outstanding characteristics facilitate both bolometric and single-photon detection in microwave and terahertz ranges. Published by the American Physical Society 2024

A quantitative description of light-limited cyanobacterial growth using flux balance analysis.

The metabolism of phototrophic cyanobacteria is an integral part of global biogeochemical cycles, and the capability of cyanobacteria to assimilate atmospheric CO2 into organic carbon has manifold potential applications for a sustainable biotechnology. To elucidate the properties of cyanobacterial metabolism and growth, computational reconstructions of genome-scale metabolic networks play an increasingly important role. Here, we present an updated reconstruction of the metabolic network of the cyanobacterium Synechocystis sp. PCC 6803 and its quantitative evaluation using flux balance analysis (FBA). To overcome limitations of conventional FBA, and to allow for the integration of experimental analyses, we develop a novel approach to describe light absorption and light utilization within the framework of FBA. Our approach incorporates photoinhibition and a variable quantum yield into the constraint-based description of light-limited phototrophic growth. We show that the resulting model is capable of predicting quantitative properties of cyanobacterial growth, including photosynthetic oxygen evolution and the ATP/NADPH ratio required for growth and cellular maintenance. Our approach retains the computational and conceptual simplicity of FBA and is readily applicable to other phototrophic microorganisms.

Characterisation of the ringed seal (Pusa hispida) acoustic repertoire during spring in the Western Canadian Arctic

ABSTRACT Understanding the acoustic repertoire of a species is crucial for comprehending its ecology and can also provide a valuable tool in the analysis of passive acoustic monitoring data. Despite being the most abundant seal species in the Arctic, the call repertoire of ringed seals (Pusa hispida) remains poorly studied. This paper aims to provide a comprehensive and quantitative description of the calls produced by ringed seals. Data collection occurred in May 2022 near Ulukhaktok in the Western Canadian Arctic. Acoustic recorders were deployed in cracks in the sea ice that were regularly used by ringed seals as haul-out areas. All calls were counted and classified into one of three categories: yelps, barks and growls. High-quality calls were further analysed with ten acoustic parameters calculated for each signal. Cluster and classification and regression tree (CART) analyses were used to assess if the visual classification of calls was supported by the acoustic parameters calculated. The cluster and CART analyses affirmed the presence of all three distinct call types in the ringed seal acoustic repertoire. Classification of unseen calls using the CART model demonstrated an accuracy of 98%. The findings presented here serve as foundational information on the acoustic repertoire of ringed seals.

Large-Deformation Modeling of Surface Instability and Ground Collapse during Tunnel Excavation by Material Point Method

Recent rapid urbanization has led to an increase in tunnel construction, escalating the prevalence of ground collapses. Ground collapses, characterized by large deformation and strain-softening, pose a significant challenge for classical numerical theories and simulation methods. Consequently, a numerical framework combining the material point method (MPM) and strain-softening Drucker–Prager plasticity is introduced in this study to more accurately describe the evolution process and failure mechanism of the subgrade during tunnel excavation. The proposed numerical framework was validated against an analytic solution employing a typical ‘dry bottom’ dam model with solid non-linearity and large deformation; some of the results are also compared with those of the SPH method and centrifugal modeling tests to verify the validity of the MPM method in this paper. The validated model was used in this study to conduct a comprehensive analysis of surface instability and ground collapse under varying soil conditions. This included factors such as strata thickness, cohesion, internal friction angle, and a quantitative description of the development of longitudinal subsidence of the surface. The aim was to clarify deformation responses, failure patterns, and excavation mechanisms, providing insights for underground tunneling practices.

Analyzing multispectral emission and synchrotron data to evaluate the quality of laser welds on copper

The validation of laser welding of metallic materials is challenging due to its highly dynamic processes and limited accessibility to the weld. The measurement of process emissions and the processing laser beam are one way to record highly dynamic process phenomena. However, these recordings always take place via the surface of the weld. Phenomena on the inside are only implicitly recognizable in the data and require further processing. To increase the validity of the diagnostic process, the multispectral emission data are synchronized with synchrotron data consisting of in situ high-speed images based on phase contrast videography. The welding process is transilluminated by synchrotron radiation and recorded during execution, providing clear contrasts between solid, liquid, and gaseous material phases. Thus, dynamics of the vapor capillary and the formation of defects such as pores can be recorded with high spatial and temporal resolution of <5 μm and >5 kHz. In this paper, laser welding of copper Cu-ETP and CuSn6 is investigated at the Deutsches Elektronen-Synchrotron (DESY). The synchronization is achieved by leveraging a three-stage deep learning approach. A preprocessing Mask-R-CNN, dimensionality reduction PCA/Autoencoders, and a final LSTM/Transformer stage provide end-to-end defect detection capabilities. Integrated gradients allow for the extraction of correlations between defects and emission data. The novel approach of correlating image and sensor data increases the informative value of the sensor data. It aims to characterize welds based on the sensor data not only according to IO/NIO but also to provide a quantitative description of the defects in the weld.

EFFECTIVENESS OF BEMO: AN ANDROID-BASED EDUCATIONAL GAME AS A LEARNING MEDIA ON MOLECULAR SHAPE MATERIAL

This study analyzes the effectiveness of the android-based BEMO game as a learning media on molecular shape material. The trial in this study was conducted on one of the XI classes at SMA Kartika IV-3 Surabaya, namely class XI E with 30 students. Effectiveness is based on pretest and posttest results comprising 15 questions and questionnaire results comprising 12 statements. Learning outcomes were analyzed with the help of the SPSS program, while the questionnaire results were analyzed by quantitative description. The results of the analysis with the help of SPSS show that the use of the android-based BEMO game as a learning media on molecular shape material is effective for improving student learning outcomes by conducting the Paired Samples T-Test test which is known t table with df = 29, α 5% = 1.669 while t count = 26.133. This shows a significant difference in students' learning outcomes on molecular shape material between the pretest and posttest. The posttest results were also analyzed with classical completeness getting a percentage of 86.67%. Based on the data obtained from the students' response questionnaire, it is known that students feel happy to learn when using the BEMO game so that students can participate actively, have increased concentration and willingness to learn and feel comfortable when undergoing the learning process. Based on this data, it can be concluded that using android-based BEMO game as a learning media on molecular form material is effective in significantly improving students' learning outcomes

Electrophile-Arene Affinity: An Energy Scale for Evaluating the Thermodynamics of Electrophilic Dearomatization Reactions.

Rational design and development of organic reactions are lofty goals in synthetic chemistry. Quantitative description of the properties of molecules and reactions by physical organic parameters plays an important role in this regard. In this Article, we report an energy scale, namely, electrophile-arene affinity (EAA), for evaluating the thermodynamics of electrophilic dearomatization reactions, a class of important transformations that can rapidly build up molecular complexity and structural diversity by converting planar aromatic compounds into three-dimensional cyclic molecules. The acquisition of EAA data can be readily achieved by theoretically calculating the enthalpy changes (ΔH) of the hypothetical reactions of various (cationic) electrophiles with aromatic systems (taking the 1-methylnaphthalen-2-olate ion as an example in this study). Linear correlations are found between the calculated ΔH values and established physical organic parameters such as the percentage of buried volume %VBur (steric effect), Hammett's σ or Brown's σ+ (electronic effect), and Mayr's E (reaction kinetics). Careful analysis of the ΔH values leads to the rational design of a dearomative alkynylation reaction using alkynyl hypervalent iodonium reagents as the electrophiles.

Development of an Improvised Solar Powered E-Grass Cutter: Utilizing Microcontroller Technology

Thesis Abstract: Farmers were greatly impacted by the improvised solar-powered e-grass cutter that used microcontroller technology. This might be used to agriculture and encourage farmers to develop equipment and products made of recycled materials. The current study primarily focuses on the development, design, and evaluation of an improvised solar-powered E-Grass cutter that makes use of microcontroller technology. The actual questionnaire that was distributed to the chosen respondents was used by the researchers. The researchers utilized descriptive statistics to interpret the data because they provide a quantitative description or summary of the characteristics of the data collection. The weighted mean and percentage were employed in all statistical calculations. According to the study's findings, 26 of the respondents were farmers. Functionality, durability, and usability all received weighted averages of 3.60, 3.93, and 3.61. and safety achieved a weighted average of 3.53 overall. According to the evaluation of the farmers utilizing the E-grass cutter, the makeshift E-grass cutter's functionality, durability, usefulness, and safety all satisfied the necessary standards to carry out its intended functions.

Assessing Scientific Literacy of College Students with TOSLS (Test of Scientific Literacy Skills)

This study aims to identify the scientific literacy skills of students at Malang State University based on gender, year of study, and study program. The research method uses quantitative description. The sampling technique uses purposive random sampling. The population of the study is S1 students at Universitas Negeri Malang who are pursuing education programs. The sample consists of 208 students, divided into 62 males and 146 females. The data collected includes the results of scientific literacy tests using the TOSLS (Test of Scientific Literacy Skills) instrument and demographic data from the respondents obtained through questionnaires. The test instrument is divided into nine indicators of scientific literacy, including the ability to identify scientific concepts, evaluate the validity of sources, and interpret graphs. Data analysis was conducted using the KR20 reliability test, Shapiro-Wilk normality test, and non-parametric analysis such as Mann-Whitney and Kruskal-Wallis. The results of the study showed that the average level of success in questions was 73.37%, based on gender, with details of male respondents with a score of 74.38% and female respondents with a score of 72.36%. The level of scientific literacy of students based on the year of study in working on questions decreased from the first year to the third year (first year = 37%; second year = 46%; third year = 17%). There was a difference in the level of success in completing questions statistically based on the study program, which showed significance (H = 47.93; p <0.05). Geography education students' scores in solving test questions were second worst compared to students studying Biology, Physics, and Chemistry, so they had to do more science-based activities in each lecture activity.

The effect of rotationality on nonlinear shear flow of polymer melts and solutions

By considering the rotationality of shear flow, we distinguish between tube segments created by reptation before the inception of shear flow and those created during flow. Tube segments created before inception of shear flow experience both stretch and orientation, while tube segments created after inception of flow are not stretched, but are only aligned in the flow direction. Based on this idea, the Rotation Zero Stretch (RZS) model allows for a quantitative description of the start-up of shear flow and stress relaxation after step-shear strain experiments, in agreement with data of polystyrene long/short blends and corresponding polystyrene 3-arm star polymers investigated by Liu et al. (Polymer 2023, 281:126125), as well as the shear viscosity data of poly(propylene carbonate) melts reported by Yang et al. (Nihon Reoroji Gakkaishi 2022, 50:127–135). In the limit of steady-state shear flow, the RZS model converges to the Doi-Edwards IA model, which quantitatively describes the steady-state shear viscosity of linear polymer melts and long/short blends. The assumption of “non-stretching” of tube segments created during rotational flow is therefore in agreement with the available experimental evidence. Three-arm star polymers behave in a similar way as corresponding blends of long and short polymers confirming the solution effect of the short arm in asymmetric stars. The analysis of step-shear strain experiments reveals that stress relaxation is at first dominated by stretch relaxation, followed at times larger than the Rouse stretch relaxation time by relaxation of orientation as described by the damping function of the Doi-Edwards IA model. The RZS model does not require any nonlinear-viscoelastic parameter, but relies solely on the linear-viscoelastic relaxation modulus and the Rouse stretch relaxation time.Graphical

A bud's life: Metabarcoding analysis to characterise hazelnut big buds microbiome biodiversity

Despite Corylus avellana L. being an economically important shrub species known for its resilience to adverse environmental conditions, it constantly faces attacks from a plethora of biotic entities. Among these, the mite pest Phytoptus avellanae is gaining importance, causing economic losses every year. This mite colonises the new generative and vegetative buds, leading them to become swollen and reddish, and drastically reducing hazelnut production. The biology behind gall formation is still poorly understood. This study provides a qualitative and quantitative description of the microbiome in both healthy and infested buds of two economically important hazelnut cultivars through metabarcoding of fungal ITS and bacterial 16 S. Potentially pathogenic genera such as Fusarium and Pseudomonas were predominant in the infested buds, along with the obligate intracellular bacterial genus Wolbachia. Akanthomyces muscarius was instead isolated from culture-based methods only from the infested buds. These findings could improve the understanding of gall ecology, supporting the management of mite populations, and they could also serve as a milestone for further studies on low-impact, monitoring-driven, and genetically targeted control strategies.

Experimental investigation on cooling load caused by unorganized ventilation in subway station: A case study

Unorganized ventilation significantly increases the energy consumption of subway stations. However, the quantitative description of cooling load caused by the unorganized ventilation in subway stations with platform screen doors (PSDs) still needs to be explored in depth. This study firstly proposed an experiment-based method to determine the airflow rate of unorganized ventilation, and then the corresponding cooling load is determined. Based upon this method, a series of field tests were conducted at a subway station in Shanghai. By analyzing the experimental data, the characteristic of unorganized ventilation at PSDs and entrance/exit passages was obtained. As for PSDs, the volume of unorganized ventilation in a cycle (the period from the upward train entering the station to the next upward train starting to approach the station) from the tunnel to the platform and from the platform to the tunnel is 2112.24 m3 and 4219.31 m3, respectively. With regard to entrance/exit passages, the volume of unorganized ventilation is 2655 m3 in a cycle. Thereafter, the above-mentioned results were used to determine cooling load. Owing to the difference in the departure density of train on weekdays and weekends, two typical summer days were selected for the purpose of cooling load analysis. The overall cumulative value of the cooling load caused by unorganized ventilation was 1416 kWh on a working day and 1718 kWh for the weekend, which accounted for 16.74 % and 19.19 % of the daily cooling load, respectively.

Influence of contouring on the microstructure and micromechanical properties of Laser Powder Bed Fusion (LPBF) processed Al6061 enhanced with reactive particles

Age-hardenable aluminum alloys are of interest for powder bed fusion (PBF) additive manufacturing to produce lightweight, high-performance custom components. The successful processing of these alloys depends on specific alloying and print techniques to overcome defects that significantly degrade mechanical properties of PBF aluminum. The Reactive Additive Manufacturing (RAM) process modifieds alloy feedstock with reactive precursors which inoculate equiaxed microstructures during solidification, resulting in a reduction of columnar grain growth and shrinkage cracks. Additionally, surface quality is addressed by contouring, which retraces the perimeters of printed layers to produce smooth, fully fused surfaces. However, the combination of RAM and contouring methods has not been previously described in the literature, raising questions about the extent of refinement which is achieved when RAM particles are remelted by contouring laser sweeps. In this research, X-ray microcomputed tomography (XCT) was used to provide a complete characterization of RAM particles and defects in an AA6061-RAM alloy in 3D. The non-destructive XCT technique was used to quantify pore and particle distributions in the contoured alloy volumes and compared directly to hatched regions. The resulting three-dimensional analysis was correlated to traditional 2D microstructure quantification and nanoindentation experiments, providing a multimodal quantitative description of sub-micron grains, reaction products, and micromechanical properties. The study reveals that RAM particles inhibit cracking while simultaneously reducing the variance in mechanical properties between hatched and contoured regions of the build volume.

Evolution mechanism of organic macromolecular structure during lignite pyrolysis

Understanding the mechanisms governing coal pyrolysis reactions, particularly in relation to the coal macromolecular structure, is crucial for improving energy efficiency and facilitating the transition of coal into a clean energy source. This study employs cutting-edge techniques, such as High-Resolution Transmission Electron Microscopy (HRTEM) and Thermogravimetric Analysis coupled with Fourier Transform Infrared Spectroscopy and Mass Spectrometry (TG–FTIR–MS), to analyze lignite and its residual solid samples subjected to pyrolysis across a range of temperatures from 300 °C to 1100 °C. The variational characteristics of the macromolecular structure during coal pyrolysis are examined. Utilizing molecular dynamics simulations, we analyze the evolution mechanism of the macromolecular carbon structure of organic matter during the coal pyrolysis process. The results show that the pyrolysis can be divided into three distinct phases: activation (30–300 °C), pyrolysis (300–650 °C), and condensation (650–1200 °C). During these phases, the coal structure undergoes complex transformations, including folding, twisting, shedding of small molecular side chains, and breaking of macromolecular side chains, ultimately leading to the directional arrangement of structural fragments. The structural units initially undergo decomposition, followed by growth and alignment in a certain direction. The spatial distribution of aromatic structural units evolves from local ordering to complete disordering, culminating in larger-scale, three-dimensional ordering. The order of bond breaking within the macromolecular structure of lignite pyrolysis is: oxygen-containing functional groups (such as C–O and COOH) > aliphatic structure (N–C and C–C) > aromatic structure (CC). By uncovering the reaction intermediates and pathways involved in lignite pyrolysis, this research provides a comprehensive quantitative description of the coal pyrolysis process. These insights offer invaluable theoretical support for the industrial-scale pyrolysis of coal, paving the way for more efficient and sustainable utilization of this crucial energy resource.