Journals@UC (University of Cincinnati)
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Fish Oil Free Odorless Chamois Leather Making using Tung Oil - A Short Communication: Renganath Rao Ramesh, Bindia Sahub and Muthukumaran Ponnuvela
No full textTraditionally, chamois leather is made predominantly using fish oil. The significance of fish oil is mainly attributed to the presence of highly unsaturated chains that are susceptible to oxidation and polymerisation, leading to the generation of aldehydes and free radicals, which can stabilise collagen during the oil tanning process. Due to the pungent smell of fish oil, Tung oil has been tried as a replacement for the oil tanning of sheep and goat skin in this research work. The potassium and ammonium persulphate have been used as inorganic catalysts to accelerate the oxidation process, reducing the process time from 10-15 to 4-5 days. The characteristic properties of experimental leathers, such as tensile, tear and water absorption, were better than those of fish oil-tanned leathers. Therefore, these results suggest that tung oil can be an alternative to fish oil in chamois leather production
Artificial Intelligence Literacy and Information Literacy: Small ways to add AI literacy into library instruction sessions
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Prevalence and Quality of Common Skin Defects in Tanneries Around Bahir Dar: by Hafeezullah Memon, Eldana Bizuneh Chaklie and Mulugeta Muche Birhanu
No full textThe leather and leather products industries play a significant role in the Ethiopian economy due to the country’s enormous potential in livestock. However, the sector is losing a substantial amount of revenue because of quality issues and declining export prices resulting from the degradation of skins and hides. The primary objectives of this paper are to assess current quality levels, identify the most prevalent types of defects, and determine their occurrence in pickled and wet blue skin defects at the Bahir Dar and Anbessa tanneries. This study employs a cross-sectional survey and observations, gathering both qualitative and quantitative data. Consequently, the common defects found in Ethiopian hides and skins that exhibit higher prevalence and severity levels have been analyzed. According to the data, scratches (89%) and cockle (86%) were identified as major defects on goat skins, while holes (86.5%) and cockle (81%) were the primary defects on sheep skins. Understanding the consequences of various types of defects is essential for tanneries, as no two defects impact the material’s value or quality in the same way. Thus, this study highlights the key areas companies should focus on and provides valuable insights and data to guide future research aimed at improving skin processing practices
Public Speaking in the Metaverse: Integrating Public Speaking and Extended Reality to Improve Students’ Presentation Skills
Full text linkWith the increased advancement and accessibility of digital technologies, instructors and educators continue to experiment with immersive reality to foster students’ engagement and experiential learning. The use of extended reality (XR) provides new and exciting ways for students to practice various skills — including communication ones — in a safe and realistic environment. In this activity, I describe and reflect on how I integrated XR in my public speaking class with the goal of helping students refine their presentation skills and simulate different speech contexts that would be difficult to replicate in the traditional classroom environment. Students’ experiences suggest that, although XR cannot (and should not) replace in-person public speaking, it can provide meaningful simulations and even help to alleviate public speaking anxiety for unknown and unfamiliar situations
A Course Designed to Improve Students\u27 Critical and Creative Thinking in the Life Sciences
Full text linkStudents in the life sciences first-year program at NC State University enroll in a course focused on critical and creative thinking. The course is discussion-based with small groups working on problems and case studies associated with the neuroscience of learning, critical and creative thinking, rhetoric in science, diversity in STEM, and experimental design. Groups also work on a semester-long project tying together many of the course topics. Course design and best practices are discussed for adoption and implementation to help grow students’ critical thinking and creative thinking skills. Results support that group work all semester helped student learning gains, and that students rank improvement in their understanding of course content as well as skills in the area of argumentative writing and discussions.
Effect of Pressure Treatment on Structure and Mechanics of Crust Leather
No full textChemical modification has traditionally resulted in good leather mechanical properties; but this approach incurs high costs and contributes to significant environmental pollution. A physical approach can enhance the mechanics of leather, while lowering its cost and environmental load. In this study, the Cr-tanned crust leather was treated by pressures from 0 MPa to 37.5 MPa, significantly improving mechanical properties such as tensile (by 108%) and tear strength (205%) without adding any chemicals or reducing softness. Pressure treatment altered the diameter and D-spacing of fibrils and deformed the pore-size distribution. The higher tensile properties (32.6 to 67.9 MPa) of crust leather were obtained with pressure increasing, resulting in a reduced pore diameter (1142 to 212 nm) and larger specific surface area (3.2 to 6.4 m2/g). Pores in crust leather were categorized into 5 types by fractal dimension, and the properties (elongation at break, softness, and tear strength) were associated with pores of diameter below 200 nm. This study offers a novel approach to enhancing the mechanical properties of leather without using additional chemicals, resulting in cleaner leather processin
High Chrome Exhaustion by Using Oxidized Tragacanthin as a Natural Pre-Tanning Agent in Leather Industry
No full textPre-tanning agents can alter collagen and improve the efficiency of chrome tanning in the leather industry. In this work, tragacanthin (TRG) was separated from gum tragacanth (GTR) and oxidized by hydrogen peroxide (OTRG). The possible use of OTRG as chrome absorbent was evaluated before using it as a pre-tanning agent. The results showed the 96.7% chromium absorption from solution. After that, the OTRG was used for chrome uptake, resulting in high chrome exhaustion (90.71%) and high shrinkage temperature (Ts=114 °C) over the conventional chrome tanning. The SEM images of wet-blue revealed the dispersed collagen fibers. The use of pre- tanning agents significantly enhances the mechanical properties of leather. With tensile strength of 301.53 kg/cm², elongation at break of 47.02%, and tear strength of 50.11 kg/cm, these improvements indicate that the pre-tanning process effectively contributes to the durability and flexibility of the final leather product. This enhancement not only improves performance but also expands the potential applications of leather in various industries. So, TRG, being a natural polysaccharide, can function as a pre-tanning agent for high chrome exhaustion
Technical Note – Novel Condensates with High Bio-Based Content as Syntan Replacements
No full textSyntans are widely used in leather making. They are made from fossil-based phenol and formaldehyde. Both building blocks are toxic. Many syntans currently have high values of bisphenols, some have a problem with rest-monomeric formaldehyde. This is why the search is ongoing for re-tanning agents made from less toxic and preferably renewable starting materials, that can substitute for syntans avoiding formaldehyde and bisphenol issues.
In this article novel condensates are introduced that are obtained by condensation of dicarboxylic esters with renewable aromatic aldehydes. A subsequent reaction leads to complete water solubility. A preferred aromatic aldehyde is vanillin, which is commonly used in nutrition, avoiding any toxicity issue. Vanillin can be obtained from a waste stream of the paper industry.
In application on leather, these novel condensates could achieve or outperform the performance of syntans and vegetable tanning agents in re-tanning concerning softness, fullness, and fastness properties. No formaldehyde was used in the condensation, no bisphenols formed. The synthesis is facile and dominantly renewable starting materials were chosen as building blocks. These results have been presented at the 12th Ledertage conference in Salzburg, Austria in June 2024.
Additionally, this article will present for the first time, results of the application of these condensates in sole tannin