Journals@UC (University of Cincinnati)
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Study on the Chemical Kinetics of the Degradation of Conventional Vegetable-Tanned Leather in Simulated Acidic Burial Environments
No full textThe degradation mechanism of leather is an important research topic in the conservation of leather artifacts, encompassing the effects of physical degradation, chemical degradation, and biodegradation on leather relics. Considering the value of leather artifacts, this study investigated the degradation of vegetable-tanned leather in acidic burial environments. The conventional vegetable tanning method was employed to tan salt-dried hides of sheep, cattle, yak, horse, donkey, and rabbit, which served as substitutes for ancient leather samples. To study the apparent chemical kinetic process and rate of leather degradation, multiple samples were artificially aged in a simulated acidic burial environment and the degradation rates for each leather type were characterized at different aging stages, by measuring changes in puncture strength, The results indicated that the degradation of sheep, cattle, yak, horse, donkey, and rabbit leathers in an acidic environment mainly followed first-order reactions, and the corresponding leather samples exhibited half-lives of 3.2, 3.9, 2.7, 1, 0.7, and 0.7 days, respectively. Therefore, cattle leather exhibited the lowest degradation rate, while rabbitleather exhibited the highest degradation rate under the same aging conditions
Phenotypic Characteristics and Antibiotic Resistance Profiles of Proteolytic Halotolerant Bacillus Species Isolated from Curing Salts Used in Leather Industry and Their Inactivation by 1 Amp Direct Electric Current
No full textProteolytic halotolerant Bacillus species that may adversely affect leather quality are the predominant bacteria found in the curing salt samples used in the leather industry. Therefore, this study aims to examine the growth of 83 proteolytic halotolerant Bacillus isolates (B. amyloliquefaciens, B. atrophaeus, B. halotolerans, B. licheniformis, B. mojavensis, B. paralicheniformis, B. pumilus, B. safensis, B. siamensis, B. subtilis, B. tequilensis, B. velezensis) recovered from 30 salt samples at different temperatures, pH values, enzymatic activities, utilization of carbon and amino acid sources, antibiotic resistance profiles of these species against medically important antimicrobials and the inactivation effect of 1 A (amp) direct electric current (DC) on a mixed culture of proteolytic and lipolytic halotolerant Bacillus isolates in a brine solution with 0.85% NaCl. All Bacillus isolates grew between 20-45°C and pH 6-7. Most isolates grew at pH values ranging from 5 to 10. None of the Bacillusisolates grew at pH 4, 5°C, and 65°C. All salt samples contained Bacillus isolates with multiple hydrolytic enzymes. All test isolates produced caseinase enzyme. Although most Bacillus isolates produced cellulase, amylase, β-galactosidase, and xylanase, some Bacillus isolates produced urease, lipase, deoxyribonuclease, and pullulanase enzymes. While all Bacillus isolates utilized glucose, sucrose, and L-methionine, most isolates used ribose, L-cysteine, L-hydroxyproline, L-alanine, L-aspartic acid, L-isoleucine, glycerol, lactose, L-histidine, L-arginine, L-glycine, L-valine, L-leucine, L-glutamic acid, L-phenylalanine, and galactose. In addition, L-lysine, L-proline, L-tyrosine, L-serine, and L-threonine were used by some test isolates. Amino acid utilization test results showed that when the proteolytic enzyme of Bacillus isolates breaks down the collagens into amino acids, these isolates can use amino acids as nutrients to grow and subsequently damage salted skins. Multidrug-resistant Bacillus isolates, exhibiting resistance to three to six antibiotics, were common in the curing salt samples. Resistances of Bacillus isolates against vancomycin (5 µg) and erythromycin (15 µg) were found to be high. Resistances against clindamycin (2 µg), norfloxacin (10 µg), ciprofloxacin (5 µg), and levofloxacin (5 µg) of some isolates were detected. A 1A DC treatment killed the mixed culture of multidrug-resistant proteolytic halotolerant Bacillus species with high catabolic activity at a voltage level of 10.9 V within 25 minutes. In conclusion, the examination of phenotypic characteristics, and antibiotic resistances of proteolytic halotolerant Bacillus species revealed potential characteristics of Bacillus species that can cause adverse effects on skin quality. Therefore, the extermination of the multidrug-resistant proteolytic and lipolytic halotolerant Bacillus species with high catabolic activities via the 1A DC process is very important to prevent both contamination of hides and skins with these Bacillus isolates during salt curing processes and the development of antimicrobial resistance and spread on salted skins and hides in the leather industry
Using a Custom GPT to Support Theory Application and Reflective Practice in a Graduate-Level Organization Theory Course
Full text linkThis personal narrative describes my integration of a custom GPT into a graduate-level organization theory course to promote critical thinking and ethical leadership. In response to students using A.I. to shortcut the course project, I structured assignments and grading rubrics to require detailed organizational context and theory application, making uncritical A.I. use ineffective. A course-specific GPT, trained on class materials and guidance, supported students as a reflective partner in developing insights and applying theory. My observations from three sections (n = 46) suggest improved engagement, clarity, and relevance in student work, though some still misused A.I., resulting in Cs
Teaching Teachers in the Age of AI: A Faculty Reflection on Lesson Planning
Full text linkIn this narrative, the author reflects on the tensions and opportunities that artificial intelligence (AI) introduces to teacher education, with particular attention to lesson planning. Concerned that AI tools like ChatGPT might undermine the development of the deliberate thinking required of effective teachers, the author collaborated with colleagues to adapt their approach to teaching lesson planning to include structured AI-supported critique. The resulting instructional framework integrates AI feedback as one of several reflective checkpoints in a gradual release of responsibility process. Ultimately, this essay argues that, when used intentionally in teaching lesson planning, AI can support preservice teachers\u27 in learning to think like a teacher.
Artificial Intelligence in Online Graduate Professional Education: Integration, resistance, and reconciliation of AI podcasts and tutor chatbots
Full text linkIn a masters-level asynchronous seminary course, I integrated generative AI (genAI) in ways aimed at providing some of the benefits of synchronous discussion. With Notebook LM, I created podcasts that discussed primary historical documents. And with a chatbot of their choice, students engaged in tutoring sessions with genAI. Some students resisted genAI, but overall discomfort decreased over the first few weeks. Many students testified to the benefits of genAI for their understanding of historical documents. Future iterations will communicate more clearly the technical components and pedagogical rationale
Ask… and Tell: Acknowledgement of AI Use in Course Syllabi
Full text linkThis article outlines the strategy I have utilized in beginning to integrate Artificial Intelligence into my undergraduate courses. I have taken the approach of first and foremost naming it. I communicate an awareness of AI to make it clear that I know that AI exists and how it can be used, and misused. I also acknowledge that I do not know everything about it at this juncture, and I invite my students to embark on the journey of discovery with me, holding true to one of the core mission values of our university: faculty and students supporting each other in lifelong learning. Finally, I name the rules of engagement, indicating when it is acceptable to use AI and when it is not. I am also able to remind students that any time they consult outside sources for their writing they must cite those sources appropriately, even if that source is AI, turning this into a pedagogical experience on multiple levels
From Demonstration to Collaboration: Redefining AI Integration in Educational Workshops and Consultations
Full text linkDeterioration Characteristics of Various Simulated Samples of Ancient Tanned Leathers: A Comparative Study: by Shuli Yao, Hailiang Yang, Haoyue Li, Yue Yu, Ya-nan Wang, Yang Zhou, Bi Shi and Yunhang Zeng
No full textArchaeological leathers were tanned using different methods. However, the influence of tanning methods on the long-term stability of these leathers remains unclear. In this study, artificially aged leather samples with varying degrees of deterioration were prepared using antique smoke, vegetable, and aluminum tanning techniques, along with accelerated aging via composting. The samples were analyzed, and results indicated that the smoke-, vegetable-, and aluminum-tanned leathers exhibited surface roughness; color change; disruption of the collagen fiber network; reduced porosity; and decreased thermal stability, mechanical strength, and softness as the degree of deterioration increased. Furthermore, different trends in moisture and collagen (assessed via hydroxyproline) contents were observed in all the artificially aged samples compared with their unaged counterparts. Smoke-tanned leather exhibited reductions of 40.61% in moisture and 75.49% in hydroxyproline after five days of ageing, and aluminum-tanned leather showed reductions of 34.4% in moisture and 76.30% in hydroxyproline after 10 days of ageing. Conversely, vegetable-tanned leather showed increments of 54.69% in moisture and 35.66% in hydroxyproline after 30 days of ageing. This phenomenon occurred because the hygroscopicity of the vegetable tanning agent was higher than that of the two other agents, and the degradation of vegetable tannins was more rapid than that of collagen during deterioration. These findings demonstrate the important effects of tanning methods on the deterioration of archaeological leathers and suggest that accurate identification of the tanning method is vital for predicting deterioration trends and designing effective preservation strategies for these artifacts