Recovered Carbon Black (rCB) from scrap tire pyrolysis offers a potential alternative to fossil-based virgin Carbon Black (CB) in the context of a circular economy. This study investigated the influence of pyrolysis process parameters on rCB yield and quality at laboratory and semi-industrial scales. The resulting rCBs were characterized and found to have surface and structural properties comparable to N500 and N600 series CBs, but with higher mineral and volatile contents. The quality of rCB is influenced by the feedstock composition, particularly the ratio of organic to inorganic components as well as key process parameters such as heating rate, pyrolysis temperature and residence time. Higher heating rates accelerate degradation and shift product distribution toward increased oil yield and reduced rCB formation, while higher pyrolysis temperatures lead to lower volatile content in rCB. Additionally, reactor and process design affect heat distribution, transfer efficiency, and mixing behavior, further shaping rCB properties. However, further testing is required to evaluate the actual in-rubber properties of rCBs. Therefore, additional tests are planned, incorporating rCB into butyl and nitrile rubber-based elastomer compounds, which will be addressed in a follow-up study. In addition, data from the current experiments will support a comprehensive Life Cycle Assessment (LCA) to evaluate the environmental impacts of tire pyrolysis and rCB production compared to other recycling methods, with details to follow in a future publication.
The thermoplastic injection moulding process is very important in the plastics industry, as it enables automated production, supports high productivity and allows the production of plastic parts with complex geometries. It is possible to split into two large groups of polymers: amorphous and semicrystalline. Cooling rate and other injection moulding parameters have a great influence on the final properties of the plastic part. Regarding the use of aluminium as cavity material in injection moulds, new variables must be included in the analysis, since its thermal properties are significantly different from those presented by steels, which are traditionally used. In this way, the purpose of this study was to evaluate the effect of aluminium and steel cavities on different types of thermoplastics belonging to the two classes of polymers by assessing the injection parameters of a high-production part (automotive cup holder). In terms of productivity factors, moulds made of aluminium using semicrystalline polymers showed more significant reductions in cycle time compared to amorphous materials. Specifically, polypropylene exhibited a cycle time reduction between 40.6% and 52.5% when compared to steel moulds, while polyamide showed an even more substantial reduction, ranging between 56% and 63.5%. As for warpage, the amorphous materials displayed the lowest values for both types of moulds, but they also exhibited greater variations in isothermal simulations compared to semicrystalline materials. In relation to the mould materials, aluminium mould exhibited the lowest warping results and smaller variations compared to the isothermal analyses for all polymers.
Pacemaker programming recommendations in patients post-heart transplant include a higher lower rate limit, activating rate response mode, maximising battery longevity and minimising ventricular pacing in patients without atrioventricular block. This study sought to investigate how variability in pacemaker programming following orthotopic heart transplant affects morbidity. We conducted a retrospective analysis of heart transplant recipients at a single transplant centre between 1991 and 2023. Patients requiring pacemaker implantation following transplantation were matched with non-pacemaker recipients by age, sex and height. Patient and device characteristics were reviewed. Clinical outcomes, programming and physiological parameters were compared within the pacemaker group and between subject and comparator groups. Forty-five heart transplant recipients were included: 15 with pacemakers and 30 without. Within the pacemaker group, 20% were programmed with LRL > 60 bpm, rate-response mode in 47% and algorithms minimising ventricular pacing in 27%. Fifty-three percent were NYHA class I, and 46% NYHA class II; resting heart rate was similar between the groups (85 (SD14.9) and 79 (SD8) bpm: p = 0.33). NYHA class I group achieved a higher workload (METS 9 (SD2.7) vs. 6.9 (SD1) mL/kg/min: p = 0.21), and peak heart rate (135 (18.8) vs. 123 (14.8) bpm: p = 0.29) during exercise stress echocardiogram (ESE). The pacemaker group was more symptomatic than the comparator group (NYHA class II 46% vs. 10%: p = 0.016) and exhibited higher rates of cardiac allograft vasculopathy (53% vs. 10%: p = 0.005). There is substantial variability in pacemaker programming in heart transplant recipients. Patients who require a pacemaker have a greater symptom and comorbidity burden than those without. No identifiable physiological or programming differences stratified the greater morbidity within the pacemaker cohort.
The driving forces behind language variation and change have long been a subject of debate. One prominent approach takes a functionalist perspective and posits that the need for efficient communication shapes lexical and grammatical patterns. This paper reviews five recent studies that offer further support for the plausibility of the communicative efficiency principle while also providing new insights into other factors that contribute to efficient linguistic structures. The key findings from these studies can be summarized as follows: (1) the principle of communicative efficiency offers plausible explanations for both lexical and grammatical phenomena, addressing both synchronic variations and diachronic changes in language evolution; (2) linguistic systems achieve efficiency through multiple mechanisms such as creation bias and selective pressures favoring efficient communication; (3) in addition to communicative efficiency, language evolution is also shaped by language history, with existing structures influencing subsequent ones. By synthesizing these studies, this paper underscores the efficiency account as a plausible and inclusive explanatory framework. It also stresses the need to rigorously delineate the role of communicative efficiency in language evolution, cautioning against automatically conflating the presence of efficient structures with intentional optimization for communicative goals.
Human behavioral ecology is an evolutionary framework that attempts to understand how adaptive human behavior maps on to variation in social, cultural, and ecological environments. It emerged as a coherent framework in the United States and the U.K. in the 1980s and has flourished as an explanatory framework ever since. The concentration of HBE scholarship in English-speaking countries has led to missed opportunities to engage other partners in testing and expanding human behavioral ecological models of human behavioral and life history variation. In this review, we provide a brief review of human behavioral ecology and describe opportunities for related scholarship in the Chinese context. We introduce human behavioral ecology holistically, including its history, methodological frameworks, pet topics, and recent integration with related fields, with a special emphasis on its recent integration with Chinese social, archaeological, and life sciences scholarship. We address potential criticisms of human behavioral ecology and how to ensure a robust and careful application of human behavioral ecology principles in the study of human behavior in China, past and present. We conclude with excitement as the remarkable variation in the Chinese behavioral landscape offers unparalleled opportunities for innovative and integrative studies.
