Pitch Structure Research Articles

Prosodic realization of identification and contrastive focus in Korean multiple accusative constructions

This study investigated how two different kinds of prominence-induced prosodic strengthening, identificational focus and contrastive focus, are phonetically realized in Seoul Korean. In the experiment, 16 native speakers produced target sentences presented in three different prosodic conditions: default reading, NP1-contrast, and NP2-contrast. The production data presented three crucial characteristics in the phonetic manifestations of prominence-induced prosodic strengthening in Seoul Korean. First, identificational focus gave rise to temporal expansion and pitch enhancement over the constructions under the focus. Second, contrastive focus brought about modification of temporal, pitch, and prosodic structures as well as pre- and post-focus compression. Finally, the two different types of prominence marking interacted with each other; the prosodic realization of contrastive focus overrode the prosodic realization of identificational focus, which was in line with the formal (syntactic) distinction of the two types of focus. To conclude, the current study demonstrates the interplay of information structure and discourse contexts in prosodic strengthening effects induced by prominence, especially in Seoul Korean, which lacks lexical stress and pitch accent.

On the role of methyl groups in the molecular architectures of mesophase pitches

The role of methyl groups on the liquid–crystal structure of mesophase pitches was investigated by combining experimental characterizations and atomic-scale computational modeling, using three pitches synthesized from different precursors. Of the three pitches, C-9 alkyl benzene and naphthalene-based pitches have 13 and 7 methyl groups per average polyaromatic hydrocarbon, respectively. By contrast, mesophase produced from a coal-tar pitch has about one methyl group. The coal tar–based mesophase pitch is hydrogen deficient or more aromatic compared with C-9 alkyl benzene- and naphthalene-based pitches. Additionally, X-ray diffraction data showed that average coherent domain sizes of C-9 alkyl benzene (3.7 nm) and naphthalene-based (3.6 nm) pitches with more methyl groups are larger than that of coal tar–based mesophase (2.4 nm). Based on the identified features, the influence of the methyl group on the layering structures was investigated via molecular dynamics simulations. The results revealed that methyl groups are critical in mesophase layering in C-9 alkyl benzene- and naphthalene-based pitches, by reducing CH-π interaction. However, similar alignment could be achieved without the same degree of methyl substitutions for the coal tar-based pitch because of stronger π-π interaction than the other precursors. The insights from this study contribute to our understanding of the formation of conventional mesophase pitch and have implications for the processing of coal-derived materials. This knowledge is vital to produce valuable products like carbon fiber and graphite from pitches.

The effect of n-heptane soluble content on the composition and structure of coal tar pitch and the preparation of needle coke

To explore the effect of n-heptane soluble (HS) content in refined coal tar pitch (RCTP) on the preparation of needle coke (NC), a series of RCTP with different HS content were prepared by the solvent method. The RCTPs were reacted at 490 °C and 0.2 MPa for 6 h to obtain green cokes (GCs), and the GCs were calcined at 1400 °C to obtain NCs. The properties of RCTPs were studied by Fourier transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance spectrum (1H NMR), and thermogravimetric (TG) analyses. The appearance and polarized microstructure of the GCs, and the Scanning electron microscope (SEM) image, X-ray diffraction (XRD) spectroscopy, Raman spectroscopy, linear expansion coefficient, and true density of the NCs were obtained and analyzed. The results show that with the decrease of HS content, the aromaticity of RCTPs increases, and the amount and length of branched chains decrease. Mesophase structures in GCs formed by these RCTPs have different types and orientations, which leads to obvious quality differences in NCs. The NC prepared from RCTP with HS content of 15.9% (RCTP-4) has the lowest linear expansion coefficient of 0.991 × 10−6 /°C, the highest true density of 2.1195 g/cm3, better fiber structure and carbon microcrystalline structure. Therefore, the HS content should be controlled not less than 15.9%, and the TI content should not be higher than 12.6% when RCTP was prepared by solvent method.

Evidence for a universal association of auditory roughness with musical stability.

We provide evidence that the roughness of chords-a psychoacoustic property resulting from unresolved frequency components-is associated with perceived musical stability (operationalized as finishedness) in participants with differing levels and types of exposure to Western or Western-like music. Three groups of participants were tested in a remote cloud forest region of Papua New Guinea (PNG), and two groups in Sydney, Australia (musicians and non-musicians). Unlike prominent prior studies of consonance/dissonance across cultures, we framed the concept of consonance as stability rather than as pleasantness. We find a negative relationship between roughness and musical stability in every group including the PNG community with minimal experience of musical harmony. The effect of roughness is stronger for the Sydney participants, particularly musicians. We find an effect of harmonicity-a psychoacoustic property resulting from chords having a spectral structure resembling a single pitched tone (such as produced by human vowel sounds)-only in the Sydney musician group, which indicates this feature's effect is mediated via a culture-dependent mechanism. In sum, these results underline the importance of both universal and cultural mechanisms in music cognition, and they suggest powerful implications for understanding the origin of pitch structures in Western tonal music as well as on possibilities for new musical forms that align with humans' perceptual and cognitive biases. They also highlight the importance of how consonance/dissonance is operationalized and explained to participants-particularly those with minimal prior exposure to musical harmony.

Correlation between chemical composition, wettability and carbon anode performance: Exploration of high quality carbon anode preparation for aluminum electrolysis

The chemical composition of coal tar pitch has a significant effect on its wettability and the performance of carbon anode for aluminum electrolysis. This study aimed to reveal the correlation among chemical composition, wettability, and carbon anode performance, as well as provide strategies for reducing energy consumption, greenhouse gases, and hazardous waste emissions during aluminum electrolysis processes. First, the chemical composition of modified coal tar pitch was regulated by adding low-temperature coal tar pitch. The effects of low-temperature coal tar pitch mixing amount on the chemical composition, basic properties, contact angle, static wettability, functional groups, and coke microstructure were studied. In particular, electron paramagnetic resonance (EPR) and atomic force microscopy (AFM) were performed to qualitatively and quantitatively analyze radical emissions and surface structure of coal tar pitch at the microscopic scale. Subsequently, the correlation of chemical composition, wettability, and performance was discussed according to the effect of low-temperature coal tar pitch on the performance of carbon anode. Results showed that the incorporation of low-temperature coal tar pitch reduced the softening point and viscosity, and the increase in fluidity improved the contact angle and static wettability. Meanwhile, the increase in volatile content and the decrease in coking value, surface roughness, nanoscale adhesion, and free radical release concentration jointly weakened the bonding strength between coal tar pitch and calcined petroleum coke. The performance of the carbon anode prepared by blending low-temperature coal tar pitch weakened, except for the ash content. Consequently, the balance between the wettability and bonding strength of coal tar pitch is essential for the preparation of high-quality anode for aluminum electrolysis.

Response surface optimization of pitch phase change densification using composite phenolic resin co-carbonization to prepare high performance carbon refractories

The response surface method was used to successfully predict the optimal addition amounts of phenolic resin and bitumen binding system for cold isostatic pressing carbon blocks as 14 wt% and 2 wt%, respectively, and ultra-high performance carbon blocks with a compressive strength of 104.25 MPa and pore sizes below 1 µm accounted for 90.8 % were predicted and prepared. We proposed the phase change densification theory for pitch successfully explaining the secondary densification of carbon blocks by pitch powder during shaping and curing. Besides, In the carbonization stage with the carbon block firing schedule, we determined that the carbon structure of pitch after carbonization with the participation of the phenolic resin matrix and organic small molecules of phenolic resin volatilization and pyrolysis consisted of lamellar carbon with a greater number of defects, and proposed that the interface between the non-graphitizable carbon after the carbonization of the phenolic resin and graphitizable carbon after the carbonization of pitch is the carbon binding mode and mechanism of the nucleation and growth of domain structures at the defects of lamellar carbon. Therefore, We determined that the mosaic and fine mosaic binding between the high strength and high brittleness non-graphitizable carbon carbonization of phenolic resin and the low strength and high ductility graphitizable carbon carbonization of pitch as well as the aforementioned carbon binding mechanism based on domain structure also were the important reasons for the performance enhancement of pitch composite phenolic resin bonded carbon blocks.

Synthesis and evaluation of petroleum-based impregnating pitch for production of high-performance artificial graphite

The pitch impregnation process enhances the properties of synthetic graphite by optimizing their physical structure of channels and pores generated during heat treatment. Synthesizing a well-balanced molecular structure of impregnation pitch (IP) is essential for facilitating impregnation and obtaining a high carbonization yield. However, achieving this delicate balance is exceptionally challenging due to the inherent trade-off relationship between these factors. To resolve this issue, we propose a stepwise pitch synthesis recipe and the molecular weight distribution (MWD) tailoring, specifically applied to the petroleum IP from pyrolysis fuel oil (PFO). The stepwise recipe is composed of a pressurized pretreatment step applied to increase production yield and coking value, followed by a thermal polymerization step. The tailoring process is systematically designed to obtain the best performing petroleum IP by effectively removing impregnation inhibitor. Our study highlights the potential benefits of using petroleum-based pitch for impregnation processes in manufacturing of artificial graphite. The impregnation performance was enhanced by 6.7% and carbonation yield was notably improved by 16.2% relative to the coal-tar derived commercial IP. Our results show that tailoring the molecular weight distribution (MWD) of the impregnating pitch enhances impregnation performance by 1.88% compared to the raw IP.

Exploring the temperature effect on line-scan profile of a pitch structure under electron irradiation

Exploring the temperature effect on line-scan profile of a pitch structure under electron irradiation

Ice template induced assembly strategy for preparation of 3D porous carbon frameworks from low-cost carbon quantum dots for high-performance lithium-ion batteries

Consider the natural similarities between the structures of coal tar pitch and carbon quantum dots (CQDs), the mass-production of low-cost zero-dimensional (0D) CQDs was achieved by using the mild oxidation with hydrogen peroxide (H2O2). The as-obtained CQDs possesses a uniformly distributed size with a diameter of 4.16 ± 0.46 nm, many oxygen-containing functional groups, distinct crystallinity nature and a production yield of ∼18 wt%. Subsequently, ice-template induced assembly coupled with carbonization strategy reveals a transition from 0D CQDs to 3D porous carbon frameworks. Differing from the well-defined porous carbon, the obtained porous carbon frameworks consist of cross-linked and twisted nanosheets, achieving a well-developed hierarchical porous structure with a reasonable specific surface area and a gradient distribution of meso/micropores. LIBs based on porous carbon frameworks as anode materials show excellent long-cycle performance, as evidenced by reversible capacity of up to 273 mAh·g−1 after 1000 charge-discharge cycles at 2000 mA·g−1. The research emphasizes a green method of preparing CQDs from representative low-value coal tar pitch and the directional transition from 0D CQDs to 3D porous carbon frameworks, providing a promising idea to prepare functional carbon materials and endow them opportunities for LIBs anode.

The effect of the molecular structure of naphthalene-based mesophase pitch on the properties of carbon fibers derived from it

The effect of the molecular structure of naphthalene-based mesophase pitch on the properties of carbon fibers derived from it

STUDY OF COAL TAR PITCH MORPHOLOGY AND STRUCTURE

The morphology and structure of the mesophase in the series: coal tar pitch (CTP) - α-fraction of CTP - carbonised α-fraction after heating to 1200 °C, were studied by scanning electron microscopy, X-ray phase and X-ray structural analysis. The X-ray structural parameters were determined: longitudinal and transverse dimensions of the lamellae and the thickness of packages, the distance between the lamellae and the number of lamellae in the formed packages. It is shown that the two-dimensional structures of carbon mesophase are ordered into three-dimensional packages during the formation of semi-coke under CTP heating. It is established that the carbon structure of CTP and its α-fraction is represented by the turbostratic and graphite-like phases. The sizes of the packages formed by the lamellae during structuring in the transverse direction in the studied samples are of the order of 18-25 Å, in the longitudinal direction 46-63 Å, the average distance between the lamellae in the studied samples is 3.46-3.52 Å.

The effect of the molecular structure of naphthalene-based mesophase pitch on the properties of carbon fibers derived from it

AbstractMesophase pitch-based carbon fibers (MPCFs) have a high modulus of elasticity, low electrical resistivity and high thermal conductivity, so can be used in many fields. Carbon fibers were prepared from two naphthalene-based mesophase pitches, one synthesized by a HF/BF3 catalytic one-step method (AR-MP) and the other by an AlCl3 catalytic two-step method (N-MP). The mesophase pitches, spun pitch fibers, pre-oxidized fibers, carbonized fibers and graphitized fibers produced from them were characterized by TG-MS, FT-IR, 13C-NMR, MALDI-TOF-MS, XRD, SEM and elemental analysis. The molecular structures and properties of mesophase pitches were compared, and the effects of molecular structures on the structures and properties of the carbon fibers produced from them were measured. In comparison to N-MP, AR-MP has a rod-like semi-rigid molecular configuration containing more naphthenic structures and methyl side chains. The pre-oxidized fibers derived from AR-MP have a better carbon layer orientation, so that their graphitized fibers have a higher thermal conductivity of 716 W/(m·K). N-MP has a higher aromaticity with a disc-like rigid molecular configuration, so that the graphitized fibers prepared from it have a higher tensile strength of 3.47 GPa due to fewer defects being formed during preparation. The molecular structures of AR-MP and N-MP have an obvious influence on the structures and properties of their graphitized fibers.

Witold Lutosławski as an innovator in the field of symphonic thematism (on the example of the Third Symphony)

W. Lutosławski (1913-1994) was an outstanding Polish composer, one of the inventors of the principle of limited (controlled) aleatorics. In his symphonic music, aleatoric and sonoric types of material interact with the thematism of the traditional type. The article is devoted to the analysis of this interaction and the identification of the dramatic role of non-traditional thematism in the musical form. The Third Symphony (1983) serves as the research material. The author of the article characterizes the expressive possibilities of aleatorics of the texture, identifies two types of sonorism, and also describes 8 types of traditional thematism used in the symphony. The "dialogue" of the two main pitch structures in the epilogue of the symphony is traced. The study allows us to conclude that non-traditional thematism prevails in the introduction and in the first part, i.e. where different types of material are exposed. On the contrary, in the second part of the symphony, the personal principle intervenes in the organization of the thematic process. The composer's will, which develops the material, collides it with each other, builds dramaturgy and leads to a certain outcome. And here (with the exception of development), traditional thematism strongly prevails. Awareness of the balance between different types of material leads to the ability to follow the plot of the symphony, which manifests itself not only in the disposition of themes, but also in the interaction of various interval complexes with each other.

Music Genre Classification Based on Machine Learning Methods

A large portion of the population globally are actively downloading and streaming music from online platforms in recent years. In many parts of the world, music has become a lifestyle instead of a luxury. As a result of music’s growing popularity, the number of sounds and music released each day and also increased tremendously as the demand growth of music. Music genre is defined as a label that is descriptive of the music category which is used to categorize music based on several characteristics including: harmonic contents, pitch, instrumentation, and rhythmic structure. A classification model used to complete this task of classifying music genres is a machine learning system designed to classify using audio signals from song tracks into different musical genres. This paper aims to investigate the different approaches, including k-nearest neighbours algorithm, random forest, artificial neural network, and convolutional neural network, to classify music genres. Model performance analysis and confusion matrix analysis are applied to compare the advantages of the different algorithms applied on music genre classification problem.

Evolution of the Composition and Melting Behavior of Spinnable Pitch during Incubation.

The physical and chemical properties of spinnable pitch showed a huge impact on the performance of resultant pitch carbon fiber even if its physical and chemical properties were slightly changed. Various polycyclic aromatic compounds and abundant free radicals existed in spinnable pitch, and there are many interactions among molecules and free radicals. The molecular structure and composition of spinnable pitch were investigated during incubation, and the effect of molecular evaluation on rheological properties of spinnable pitch was illustrated using various characterization methods in this work. It indicated that n-hexane soluble fraction mainly occurred condensation or cleavage, and a small number of heavy components were generated after a long period. The fraction of n-hexane insoluble/toluene soluble underwent molecular condensation and cross-linking in the presence of oxygen-containing radicals and aromatic hydrocarbon radicals, while toluene insoluble/tetrahydrofuran soluble fraction tended to change in large molecules of polycyclic aromatic hydrocarbons. Lastly, tetrahydrofuran insoluble fraction was condensed due to its high aromaticity during the incubation process, and the content of aromatic carbon increased. These changes of composition and structure of spinnable pitch led to its softening point, increase in viscosity and flow activation energy, and deterioration of the rheological property.

Study of Coal Tar Pitch Morphology and Structure

Study of Coal Tar Pitch Morphology and Structure

Laminating STRATH block chain technology- SWOT architectures to endure business strategy between digital transformation, firms and supply chains capabilities for sustainability

The study laminated a link between Digital Transformation (DT), firms and supply chains capabilities based on Blockchain Technology (BCT) and accordingly STRATH (STRAtegies and THreats) modelling is presented to unlock the utility of Blockchain Technology (BCT) in supply chains (SC). SWOT architectures are mined, threats are identified and expert's opinions are sought to embrace crucial strategies for elevating the fertility of BCT in SCM. Sixteen threats & six strategies are evaluated, where theoretical framework based on SWOT dimensions, STRATH model, FuDE-VIR approach, DEMATEL, and Delphi technique under the boundaries of BCT and SCM is presented to admire the novelty of present study. The study embedded two pitch structures, where in the first pitch, SWOT- BCT architectures are mined to understand current state of affairs related to BCT. In the second pitch, STRATH modelling is done with FuDE-VIR approach to react towards sustainable outcomes. The FuDE-VIR approach is developed to define crucial strategies for BCT implementation in SCM. The study documented BCT insights, cataloged contemporary facts to BCT and provided strategic guidelines for implementing BCT in company's landmarks. Eight threats components are found under cause group and eight threats components are found under effect group, where ‘Ïnvolvement of external stakeholders’ and ‘Difficulty in changing organization culture’ demonstrated the highest cause ranking behaviour. ‘Financial constraints’ and ‘Security and privacy concerns’ demonstrated the highest effect ranking behaviour. Efforts have been received towards ‘promoting legal certainty and development of clear regulatory regime’ as first level strategic driver and ‘Permitting standardized customers and defining credit score to customers and partners working in value chain’ as the second level strategic driver for admiring the utility of the BCT in SCM.

Structure of Industrial Coal Tar Pitch: Raman Spectroscopic Analysis

Structure of Industrial Coal Tar Pitch: Raman Spectroscopic Analysis

High-rate soft carbon anode in potassium ion batteries: The role of chemical structures of pitches

Soft carbons (SCs) have become a promising anode for potassium ion batteries (PIBs). However, it is challenging to maintain high capacity and long cycle life at rapid charge/discharge rate due to the sluggish insertion/deinsertion of K+. To solve this problem, the morphology of the SCs was regulated by using pitches with different chemical structures. The results showed that the chemical structure of the pitch characterized by less long aliphatic chains led to the largest average distance between polycyclic aromatic nuclei, which caused mild condensation of polycyclic aromatic nuclei and thus the formation of lamellar structures. Abundant short chains of the pitch ignited violent cyclization and aromatization and the shortened average distance, inducing violent condensation to generate the bulk structures. The cyclopenta-fused rings and aromatic methyl groups of the pitch minimized the average distance, which also built the bulk structures. More exposed defect-edge sites and larger active surface of the lamellar SC contributed to the adsorption of K+ and improved reaction kinetics. When the current density increased to 3C,bulk structures did not work while the lamellar still remained high reversible capacity of 160.9 mAh g−1 after 1000 cycles. These findings paved a new way for the design of SCs at the molecular level to satisfy high electrochemical performance at high charge/discharge rate.

Investigating metal oxide resists for patterning 28-nm pitch structures using single exposure extreme ultraviolet: defectivity, electrical test, and voltage contrast study

BackgroundTo keep up with the logic area scaling, back-end-of-line (BEOL) structures are reduced to smaller pitches, requiring faster and reliable metrology and defect detection solution.AimMetrology and detailed defect inspection at the early phases of process optimization.ApproachSingle exposure (SE) 0.33NA extreme ultraviolet (EUV) lithography was used along with a bright field mask for patterning in a metal damascene process flow of BEOL structures. We also used a dual damascene process flow for voltage contrast (VC) metrology study.ResultsScatterometry technique, together with machine learning (ML), allowed us to have fast and accurate measurements of line-space (LS) and tip-to-tip (T2T) critical dimension (CD), and prediction of electrical performance. We demonstrated characterization results of stochastic defects across various test structures of 28-nm pitch devices. We used a large-area electron beam (e-beam) tool for high-speed large-area inspection which provided us with the quick feedback on defect signatures and scope for further root cause analysis. On a separate dual damascene integration flow, we used VC metrology to capture different failure modes in the patterning process of metal trenches with tight T2T and corresponding overlapping vias.ConclusionsWe studied the impact of stochastic resist defects on electrical measurements of meander (MR) and fork-fork (FF) structures, and showed that large electrical test structures, built with a relatively simple patterning flow, can be used at the early stages of resist and patterning development, as the electrical failures are almost exclusively caused by the resist defects. In the dual damascene flow, we demonstrated that VC metrology is useful to determine the design rule parameters and capture different failure mechanisms.