Pitch Production Research Articles

Mesophase pitch-based high performance carbon fiber production using coal extracts from mild direct coal liquefaction

Mild direct coal liquefaction (autogenous pressure, no catalyst, no H2 gas) of Springfield coal in fluid catalytic cracking decant oil is shown to effectively produce coal extract precursors to spinnable mesophase pitch. This work demonstrates that the coal extract can be thermally treated to obtain mesophase pitch in a facile one-step process, bypassing the production of an intermediate isotropic pitch. Furthermore, the presence of 25 wt.% coal in the initial slurry can increase the yield to mesophase pitch nearly twofold and yield to carbon fiber by approximately 70%. The coal extract-derived mesophase pitch was melt-spun and heat treated to produce carbon fiber with graphitic texture, high modulus (>400 GPa) and tensile strength up to 943 MPa. Overall, this work demonstrates that coal can be effectively utilized to markedly amplify the mesophase pitch and carbon fiber yield from fluid catalytic cracking decant oil by relatively simple processing, while conserving utility as a precursor to high performance carbon fiber and potentially other high value graphitic products.

The Neglected Role of Asphaltene in the Synthesis of Mesophase Pitch.

This study investigates the synthesis of mesophase pitch using low-cost fluid catalytic cracking (FCC) slurry and waste fluid asphaltene (WFA) as raw materials through the co-carbonization method. The resulting mesophase pitch product and its formation mechanism were thoroughly analyzed. Various characterization techniques, including polarizing microscopy, softening point measurement, Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), were employed to characterize and analyze the properties and structure of the mesophase pitch. The experimental results demonstrate that the optimal optical texture of the mesophase product is achieved under specific reaction conditions, including a temperature of 420 °C, pressure of 1 MPa, reaction time of 6 h, and the addition of 2% asphaltene. It was observed that a small amount of asphaltene contributes to the formation of mesophase pitch spheres, facilitating the development of the mesophase. However, excessive content of asphaltene may cover the surface of the mesophase spheres, impeding the contact between them and consequently compromising the optical texture of the mesophase pitch product. Furthermore, the inclusion of asphaltene promotes polymerization reactions in the system, leading to an increase in the average molecular weight of the mesophase pitch. Notably, when the amount of asphaltene added is 2%, the mesophase pitch demonstrates the lowest ID/IG value, indicating superior molecular orientation and larger graphite-like microcrystals. Additionally, researchers found that at this asphaltene concentration, the mesophase pitch exhibits the highest degree of order, as evidenced by the maximum diffraction angle (2θ) and stacking height (Lc) values, and the minimum d002 value. Moreover, the addition of asphaltene enhances the yield and aromaticity of the mesophase pitch and significantly improves the thermal stability of the resulting product.

Laryngeal contrast and sound change: The production and perception of plosive voicing and co-intrinsic pitch

Abstract: Inspired by Beddor 2009, this article explores whether and how trading relations between coarticulatory source and effect may serve as a precursor for sound change. It aims at extending the case of vowel nasalization examined by Beddor to the relationship between closure voicing (source) and co-intrinsic pitch (effect). Through four production and perception studies, we show that the inverse source-effect relation observed for vowel nasalization is not found in the voicing contrast of French, a true-voicing language. Instead, we propose that the phonologization of co-intrinsic pitch (a.k.a. tonogenesis) originates from spontaneous devoicing (a production bias), which subsequently triggers an upweighting of pitch (a perceptual adaptation strategy).*

Laryngeal contrast and sound change: The production and perception of plosive voicing and co-intrinsic pitch: Supplementary material

Laryngeal contrast and sound change: The production and perception of plosive voicing and co-intrinsic pitch: Supplementary material

Ultrasound tongue imaging of vowel spaces across pitches in singing

One important technique in singing is vowel modification: the adjustment of the resonance space based on the sung pitch for more efficient voice production. We explore whether vowel modification is a learned technique for enhanced acoustics, or if it is a necessary articulatory adjustment for high pitch production. 16 participants without vocal training participated in a singing experiment with ultrasound tongue imaging. Participants were asked to sing sets of English vowels across their comfortable pitch range rising by semitone in a steady tempo, resembling a vocal warm up exercise. Participants sang 5 sets of vowels in total, each set consists of 5 target vowels ([i], [ɛ], [æ], [ɑ], [u]) in randomized order with 1 filler ([ɔ]) closing each breath group. Images of tongue position were splined using DeepLabCut. Preliminary results show that untrained singers tend not to adjust their tongue positions by pitch, though cases of tongue lowering occasionally occurred, particularly for the participants who sing a wide pitch range. In contrast, additional pilot data from 2 trained operatic singers showed gradual tongue adjustments across their pitch range, neutralizing vowel contrasts at their highest pitches. We discuss findings with respect to vowel-pitch interaction, drawing implications on theories of voice production.

Reducing the environmental impact of aluminum production through the use of petroleum pitch

This study is aimed at developing a technology for obtaining petroleum pitch as a binder for anode mass used in the electrolytic production of aluminum from fuel oils of catalytic liquid-phase oxidative oil cracking. A review of published data on the existing methods for obtaining petroleum pitch and its properties is carried out in order to define research directions. A method for producing petroleum pitch by catalytic liquid-phase oxidative cracking of crude oil using heterogeneous metal complex catalysts is proposed. The process of petroleum pitch production is shown to undergo several stages, including homogenization of fuel oil and modifying additives; oxidative cracking of fuel oil during heating of homogenized fuel oil in a furnace; catalytic liquid-phase oxidative cracking of fuel oil with removal of distillates; rectification of light fractions; condensation of distillates; collection of light oil products; oxidation of bottom residues by air and steam; removal of oxidation distillates and petroleum pitch; and pitch pelletizing. According to the conducted comparison of the as-obtained petroleum pitch with the B-1 coal tar pitch produced by the Altai Koks JSC, the proposed material meets the technological requirements of the Krasnoyarsk Aluminum Plant of the RUSAL company. In terms of sulfur content, the proposed petroleum pitch is superior to coal tar pitch. The experiments conducted at an aluminum plant showed the petroleum pitch to contain no harmful polyaromatic hydrocarbons, in particular, carcinogenic benz(a)pyrene. Therefore, replacement of coal tar pitch with petroleum pitch could provide technological and environmental advantages for primary aluminum producers, as well as for enterprises producing various carbon materials.

Separation characteristics of low-temperature coal tar containing solid particles by vacuum distillation: Effects of distillation pressure and solid particle content

The separation of low-temperature coal tar (LTCT) containing solid particles by vacuum distillation is essential in various applications, such as in-situ pyrolysis. However, the separation characteristics of solid-containing LTCT using vacuum distillation have yet to be fully understood. Therefore, explorations were conducted with variations in pressure and solid particle concentration by analyzing pitch with Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The FTIR demonstrated that the organic constituents exhibit greater regularity at higher temperatures, leading to a 2 % reduction in the tightly bound cyclic OH tetramers, an intricate hydrogen bonding. The structural parameters indicate a 2 % decrease in farH, alongside a decline in AR from 0.332 to 0.293. This suggests that the low-pressure distillation conditions contribute to an increased retention of aromatic hydrocarbons in pitch, potentially complicating its subsequent utilization. The reduction in F from 2.273 to 2.029 signifies a shorter aliphatic chain, indicative of an intensified degradation effect. The elevated content of solid particles results in a more rigid texture of pitch in micromorphology. This study examined LTCT pitch to clarify the separation mechanism of solid-containing LTCT, offering insights into appropriate vacuum distillation conditions for LTCT separation and aiding in the effective utilization of pitch products.

Vocal pitch matching in early childhood as a relative cognitive strength among low academic performers

In this study, using some novel measures, we examined vocal pitch matching in 4- and 5-year-old children in transitional kindergarten classrooms and, at two time points, tested relationships between children’s singing pitch accuracy and their classroom grades as well as performance on standardized measures of developing cognitive and academic skills. Consistent with previous studies, children’s grades were strongly correlated with their performance on standardized measures and differed significantly by gender, maternal education, household income and household language. In contrast, vocal pitch matching and tonal pitch processing showed no consistent relationship to grades, standardized tests or sociodemographic variables, and children with lower academic performance showed statistically equivalent pitch singing on average compared to their peers with higher grades. These findings suggest pitch processing and production abilities may be a relative cognitive strength among children doing less well in school, which may be explored for developing programmes to lift their academic performance.

The roles of prosody in Chinese-English reading comprehension

BackgroundDespite being an essential component of children's oral reading fluency, prosodic reading, which involves expressive changes in pitch patterns and pause durations, has not been explored in Cantonese-English bilingual children, whose first language (L1) is tonal, non-alphabetic, and whose second language (L2) is non-tonal, alphabetic. AimsThis study examined the development of prosodic reading and its within- and cross-language associations with reading comprehension among Cantonese-English bilingual children from second to third grade. SampleOne hundred and twenty-one 7-to 8-year-old Cantonese-English bilingual children completed initial testing in grade 2, with 52 tested in grade 3. MethodsProsodic reading was assessed using one Chinese and one English passage, each comprising six types of syntactic structures: declaratives, clause-final commas, yes-no questions, wh-questions, complex adjectival phrases, and quotatives. Word-reading efficiency, oral passage-reading fluency, and reading comprehension in Chinese and English were also measured. ResultsSpectrographic analyses revealed that these children were aware of language-independent functions and language-specific manifestations of pitch and pause cues within and across their L1 Chinese and L2 English. Wh question pitch contours emerged as the most robust link to reading comprehension across both languages, while a crossover effect occurred from Cantonese pitch to English reading comprehension. Shorter pauses for English declarative quotative sentences and phrase-final commas were concurrently associated with greater English reading comprehension. ConclusionsThese findings are interpreted within a new reading framework, the Prosodic Catalysing Hypothesis (PCH), which proposes that pitch and pause production can bridge prosody and syntax to facilitate reading comprehension.

Phase transition behavior and mesophase aging phenomenon during liquid-state carbonization of FCC decant oil

The FCC decant oil (FCC-DO), primarily comprising 2- to 5-ring aromatic hydrocarbons with short alkyl side-chains, is widely acknowledged as the optimal precursor for the production of spinnable mesophase pitch, thus achieving its high-value utilization. The preparation of spinnable mesophase pitch from FCC-DO faces the challenge associated with achieving both high mesophase content and low softening point. To address this challenge, the phase separation behavior of the isotropic matrix and the aging phenomenon of coexisting anisotropic phases are examined using high-temperature centrifugation and advanced analytical techniques. The phase transition behavior of isotropic matrix can be described by a multi-stage continuous self-assembly induced by polymerized reactions. And this dynamic assembly process is tightly related to “steric hinderance effect” and “solvent dispersion effect”, which are mainly affected by the configuration and size distribution of formed mesogens respectively. Meanwhile, the formed anisotropic phase gradually undergoes two-staged time-dependent aging behavior, leading to poor compatibility of sub-fractions and then deterioration of melt fluidity. The initial aging of the mesophase is characterized by an almost unchanged molecular weight distribution, but a transformation of molecular configuration from a semi-rigid skeleton to a rigid one. This transformation is caused by intramolecular condensation resulting from the removal of the α-CH3 shielded by adjacent aromatic rings and dehydrogenation of naphthenic rings. When the previously-formed anisotropic phase under the liquid-state carbonized conditions for a long time, the second-stage aging of mesophase is readily triggered through the elimination of the α-CH3 not shielded by adjacent aromatic rings. This gives rise to the intermolecular polymerization and a shift towards higher molecular weight. This study provides insights into the preparation of excellent melt-fluidity mesophase pitch by promoting the rapid transformation of the isotropic matrix before significant aging of the coexisting anisotropic phase.

Right, but not left, posterior superior temporal gyrus is causally involved in vocal feedback control

The posterior superior temporal gyrus (pSTG) has been implicated in the integration auditory feedback and motor system for controlling vocal production. However, the question as to whether and how the pSTG is causally involved in vocal feedback control is currently unclear. To this end, the present study selectively stimulated the left or right pSTG with continuous theta burst stimulation (c-TBS) in healthy participants, then used event-related potentials to investigate neurobehavioral changes in response to altered auditory feedback during vocal pitch regulation. The results showed that, compared to control (vertex) stimulation, c-TBS over the right pSTG led to smaller vocal compensations for pitch perturbations accompanied by smaller cortical N1 and larger P2 responses. Enhanced P2 responses received contributions from the right-lateralized temporal and parietal regions as well as the insula, and were significantly correlated with suppressed vocal compensations. Surprisingly, these effects were not found when comparing c-TBS over the left pSTG with control stimulation. Our findings provide evidence that supports a causal relationship between right, but not left, pSTG and auditory-motor integration for vocal pitch production. This lends support to a right-lateralized contribution of the pSTG in not only detecting vocal feedback errors but also driving motor commands for error correction.

Historically informed performance: songs embedded in ǀXam stories

ABSTRACT This study examines songs incorporated into stories that were collected by Wilhelm Bleek and Lucy Lloyd from their ǀXam-speaking consultants in late nineteenth century South Africa. Although many of the stories in the Bleek–Lloyd corpus have been discussed by scholars in the fields of literature, anthropology, and history, no evidence exists that any of the songs have been performed since they were transcribed in 1879. This study aims to re-introduce several songs in the ǀXam language formerly spoken by small communities of San people from the northernmost sector of South Africa. We hope that these songs will be adopted by South African choirs to enrich their repertoires. Moreover, we aim to present ǀXam songs as the earliest examples of transcribed music in South Africa based on the melodic possibilities of the musical bow. We attempt to contextualise the songs through descriptions of the !Ui languages, music making of !Ui-speaking people, and influence of pitch production of the musical bow on the song melodies. Finally, we compare two sets of notated melodies of ǀXam songs separated by several years and present them as examples of music influenced by the musical bow in South Africa.

How communication mediums shape the message

AbstractCommunication is an integral part of everyday life. Consumers chat with friends, search for information, and complain to customer service. Salespeople pitch products, employees answer questions, and market researchers ask them. But communication does not occur in a vacuum. Modalities (e.g., speaking or writing), channels (e.g., text, phone call, or email), and devices (e.g., smartphone or computer) are the mediums through which communicators communicate. While these mediums often seem incidental, might they impact what gets communicated? And if so, how? This paper offers a comprehensive framework for understanding how mediums shape the message. Specifically, we argue that modality, devices, and channels all shape communication through the same two key drivers: deliberation and audience salience. As a result, the mediums communicators use to communicate impact everything from the thoughtfulness and concreteness of communicated content to the degree to which it is self‐enhancing or honest. This work sheds light on the psychology of content production, provides insight into the drivers and consequences of communication, and highlights how emerging technologies may shape communication in the future.

Wild nightingales flexibly match whistle pitch in real time

Interactive vocal communication, similar to a human conversation, requires flexible and real-time changes to vocal output in relation to preceding auditory stimuli. These vocal adjustments are essential to ensuring both the suitable timing and content of the interaction. Precise timing of dyadic vocal exchanges has been investigated in a variety of species, including humans. In contrast, the ability of non-human animals to accurately adjust specific spectral features of vocalization extemporaneously in response to incoming auditory information is less well studied. One spectral feature of acoustic signals is the fundamental frequency, which we perceive as pitch. Many animal species can discriminate between sound frequencies, but real-time detection and reproduction of an arbitrary pitch have only been observed in humans. Here, we show that nightingales in the wild can match the pitch of whistle songs while singing in response to conspecifics or pitch-controlled whistle playbacks. Nightingales matched whistles across their entire pitch production range indicating that they can flexibly tune their vocal output along a wide continuum. Prompt whistle pitch matches were more precise than delayed ones, suggesting the direct mapping of auditory information onto a motor command to achieve online vocal replication of a heard pitch. Although nightingales' songs follow annual cycles of crystallization and deterioration depending on breeding status, the observed pitch-matching behavior is present year-round, suggesting a stable neural circuit independent of seasonal changes in physiology. Our findings represent the first case of non-human instantaneous vocal imitation of pitch, highlighting a promising model for understanding sensorimotor transformation within an interactive context. VIDEO ABSTRACT.

Reaction mechanism of ethylene tar in the air atmosphere

The reaction process of ethylene tar in the air atmosphere is very complex and contains numerous changes, which can be divided into three stages and should be further studied to guide the production of specific pitches. In the first stage, before about 310 °C, hydrogen at the benzylic position is firstly transformed into alcoholic hydroxyl, which is partly oxidized into CO and COOH/C–O–CO afterward. Most side chains except the CO groups are gradually converted into COOH and –CH2-. Continuous dehydrogenation indicates highly condensed structures in the next stage, from 310 °C to around 380 °C. With the deprivation of CO2, further oxidization leads to the form of –CH2–, which becomes the critical linkage to create larger molecules. In the third stage, the weight of the sample is close to zero at about 550 °C. Under the direction of theory, getting pitches with the needed properties may be more accessible.

A dynamic neural field model of leaky prosody: proof of concept

Recent work has shown that lexical items come to take on the phonetic characteristics of the prosodic environments in which they are typically produced, a phenomenon referred to as "leaky prosody". Focusing on pitch patterns in Mandarin, we show that leaky prosody can be derived from a flat (i.e., non-transformational, non-optimizing) model of speech production. Formalized using Dynamic Field Theory, in our model, lexical, phonological, and prosodic inputs each exert forces on a Dynamic Neural Field representing pitch. Notably, the forces exerted by these inputs reflect surface distributions in a large corpus of spontaneous speech. Our simulations showed that the flat model derives the short timescale effect of prosodic prominence on pitch production as well as the longer timescale effect of leaky prosody. By updating lexical items based on surface phonetic form, words that are consistently produced in high/low prosodic prominence positions take on the phonetic characteristics of those environments.

Successful lexical tone production of Mandarin Chinese autistic children with intellectual impairment.

Atypical speech prosody has been commonly found among autistic children. Yet it remains unknown whether prosody impairment originates from poor pitch ability in general or whether it is the result of the difficulty in understanding and using prosody for communicative purposes. To investigate whether native Mandarin Chinese-speaking autistic children with intellectual impairment were able to accurately produce native lexical tones, which are pitch patterns that distinguish word meaning lexically and serve little social purpose. Using a picture-naming task, thirteen 8-13-year-old Mandarin Chinese-speaking autistic children with intellectual impairment were tested on their production of Chinese lexical tones. Chronical age-matched typically developing (TD) children were included as the control group. Perceptual assessment and phonetic analyses were conducted with the produced lexical tones. The majority of the lexical tones produced by the autistic children were perceived as accurate by adult judges. Phonetic analysis of the pitch contours found no significant difference between the two groups, and the autistic children and TD children used the phonetic features in comparable ways when differentiating the lexical tones. However, the lexical tone accuracy rate was lower among the autistic children than among the TDs, and the larger individual difference was observed among the autistic children than the TD children. These results indicate that autistic children are able to produce the global contours of the lexical tones, and pitch deficits do not seem to qualify as a core feature of autism. What is already known on the subject Atypical prosody has been considered a maker of the speech of autistic children, and meta-analysis found a significant difference in mean pitch and pitch range between TD children and autistic children. Yet it remains unknown whether the pitch deficits are the result of impaired perceptual-motoric ability or if they reflect failure in learning sentential prosody, which requires an understanding of the interlocutors' mind. In addition, research on pitch ability of autistic children with intellectual disabilities has been scarce, and whether these children are able to produce pitch variation is largely unknown. What this paper adds to existing knowledge We tested native Mandarin Chinese autistic children with intellectual impairment on their production of native lexical tones. The lexical tones in Chinese are pitch variations realized on individual syllables that distinguish lexical meaning, but they do not serve social pragmatic purposes. We found that although these autistic children had only developed limited spoken language, the majority of their lexical tones were perceived as accurate. They were able to use the phonetic features in comparable ways with the TD children when distinguishing the lexical tones. What are the potential or actual clinical implications of this work? It seems unlikely that pitch processing at the lexical level is fundamentally impaired in autistic children, and pitch deficits do not seem to qualify for a core feature of their speech. Practitioners should be cautious when using pitch production as a clinical marker for autistic children.

Funkční hodnocení laryngoskopického vyšetření a souvislost s kvalitou hlasu a parametry hlasového pole

Summary Introduction: Previous laryngoscopy evaluation protocols have mostly focused on assessment of glottal status and morphological description of vocal folds’ shape and oscillations. The basic functional manifestations of laryngeal use, according to new protocols, include a description of supraglottic laryngeal activity. Methods: Laryngoscopic evaluation was performed as a perceptual test, performed online, using a web-based application. The degree and type of glottal insufficiency and the degree of anterior, posterior compression and lateral-medial (L-M) compression separately for each side were evaluated by a total of 15 respondents in a total of 26 video recordings of laryngoscopic examinations. In addition, the correlations between listening evaluations of the voice using modified GRBAS scales and voice range profile parameters were investigated. Results: The ratings of the laryngoscopic scales had well to excellent agreement. Agreement for type of insufficiency was just moderate. The associated ratings of L-M compression on the right and left sides showed correlations. For listening evaluation, medial compression was found to be related to the perception of habitual voice strain, and to strain and instability in the pitch range of the change of registers of the singing voice. Degree of insufficiency predicted less fullness of habitual voice in general but was also related to vocal dyspnea and weakness when calling. At the same time, it was largely responsible for the deterioration of the quality of the singing voice. Medial compression systematically reduced pitch range and the area of the voice range profile. Conclusion: The results of the perceptual evaluation can be used in further education. On their basis, didactic material for training the assessment of supraglottic laryngeal activity was prepared and published in the form of an online tutorial. The degree of insufficiency generally affects various characteristics of the speaking and singing voice. Medial compression systematically affects only the strain of the speaking voice, while in the singing voice it accentuates the strain and instability of the transitional region between registers and impairs the production of high pitches. Key words laryngoscopy – visual evaluation – voice range profile – GRBAS

Theta burst stimulation over left cerebellum does not modulate auditory feedback control of vocal production.

Accumulating evidence has shown significant contributions of the right cerebellum to auditory-motor integration for vocal production. Whether the left cerebellum is likewise involved in vocal motor control, however, remains unclear. By applying neuronavigated continuous and intermittent theta burst stimulation (cTBS/iTBS) over the left cerebellar lobule VII (Crus I), the present event-related potential (ERP) study investigated whether the left cerebellum exerts causal effects in modulating auditory feedback control of vocal pitch production. After receiving cTBS, iTBS, or sham stimulation over the left cerebellum, a group of fifteen young adults produced sustained vowels while hearing their voice unexpectedly shifted in pitch upwards or downwards by 200 cents. The effects of cerebellar stimulation were assessed by measuring the vocal and ERP (N1/P2) responses to pitch perturbations across the conditions. When compared to sham stimulation, cTBS or iTBS over the left cerebellar lobule VII (Crus I) led to no systematic changes in vocal compensations for pitch perturbations in auditory feedback. Also, the cortical N1/P2 responses did not vary significantly across the three stimulation sessions. These findings present the first neurobehavioral evidence suggesting that the left cerebellum is not causally associated with auditory feedback control of vocal production. Together with previously reported causal effects of the right cerebellum in modulating vocal pitch regulation, the present study lends support to the hypothesis that there is a functional lateralization of the cerebellum in vocal motor control though auditory feedback.

Mesophase pitch production from fluorine-pretreated FCC decant oil

• Effect of fluorine treatment over FCC-DO for mesophase formation firstly suggested. • Reaction mechanism of mesophase formation by fluorination was suggested. • Fluorine promoted radical polymerization of FCC-DO to form heavy mesophase nuclei. • The amount of hydrogen donating species also increased after the fluorination. • Pitch from fluorinated DO had higher mesophase yield than pitch from pristine DO. Petroleum residue oil-based mesophase pitch production suffers from its low yield of mesophase. There have been continuous efforts, such as catalyst-assisted reactions and multistep heat treatments, to produce high-purity mesophase pitch. However, most of these techniques have difficulties with the processability. In this study, we suggest a novel fluorine pretreatment of fluid catalytic cracking (FCC) decant oil for mesophase pitch (MP) production. The effects of fluorine pretreatment on FCC decant oil were evaluated with mass spectrometry (MS) and their hydrogen donating ability. Subsequently, the MPs from pristine pitches with fluorine pretreatment were intensively compared in terms of structural, thermal, and chemical characteristics. From these results, it was found that fluorine pretreatment helps mesophase formation by catalytic radical polymerization but does not cause coking and does not require posttreatment. It was found that the fluorination method can also provide an effective method for generating MP by increasing the hydrogen donating ability (HDA) fraction. We believe that the results of this work could inspire new insights into MP production.