Tumen Wuliji

Dr. Tumen Wuliji

Small Animal Research Facility, Lincoln University of Missouri, Jefferson City, MO, USA

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 July 2024 in Microscopy and Microanalysis
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Journal Article
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TWTumen Wuliji
Tumen Wuliji
Specialty animal fibers are harvested from a group of domestic or wild animal’s fleeces including Camelidae, Caprine and Ovine species, and used in textile processing or products. The major focus of quality control and validation were on cashmere, camel, alpaca, vicuna and llama hair, mohair, superfine sheep wool, and their blends in the raw fiber trade or textile products, among which exist a significant price and consumer preference compared to substitute materials. This study was conducted for technical training of animal science graduates and fiber metrology technicians operating scanning electron microscope (SEM, EM-30AX Plus, Coxem) and energy dispersive spectroscopy (EDS, Oxford Instruments) to master technical skills for specialty fiber identification. SEM and EDS examination specimens were prepared from goat Cashmere, Camel hair, Suri Alpaca, Huacaya Alpaca, Vicuna, Llama, Merino, Carpet wool, Mohair, and Human hair samples. The substitutive material specimens were prepared from Cotton, Lenin, Polyester, Viscose, blend yarn, and fabrics. The specimens were washed in organic solvent (hexane), dehydrated in a serial gradient alcohol at 70, 80, 90 and 100% concentration, and the critical point drying (Leica EM CPD300). A small bundle of fiber was clipped 5 mm snippets and stick to double sided carbon tape onto SEM stub in replicate prior to sputter coating (Ted Pella) with a gold film of 20 Å in thickness. The SEM observation, measurements, and examination procedures were referenced with IWTO DTM-XX-97 standards [ 1] and the earlier established procedure [ 2] with some modifications. Fiber characteristics measured with SEM were fiber diameter (FD, µm), fiber cuticle scale frequency/length (CSF/100 µm), cuticle scale length (CSL, µm), and cuticle scale height (CSH, nm). The EDS elemental distribution analysis was selected for 20 elements including C, O, N, S, K, Cu, Fe, Si, AL, and Na estimate (%). Ten individual fibers of each specimen were scanned and counted for these elemental contents at 20Kv. The results indicate that SEM examination of specialty fiber at the magnification of 200-500x determined FD of fiber in all categories with 100% accuracy and repeatability. Fiber CSF, CSL and CSH were shown to be distinguishable among sheep wool, goat cashmere and mohair, and camelid’s fiber category, and all were separable from human hair, blend materials and non-animal fibers. The mean CSH was ranked in the higher order of sheep wool (Figure 1), goat (Figure 3), Camel (Figure 3), and South American camelids (Figure 4), whereas Suri alpaca fiber CSH was the lowest (P<0.05) among all fiber at the same diameter. Fiber CSF in the length unit was recorded higher for camelids than wool and goat fiber. Vicuna fiber of same diameter possessed the higher CSF than llama and alpacas. The EDS measured elemental profile, especially N and S content was significantly (P<0.01) high in animal fiber and differed from non-animal fibers. Therefore, the N and S content can be referenced for distinguishing animal fibers from the others. Particularly, S was amino acid components of keratin in animal hairs. The average elemental S content was measured at 5.4%, 5.1, 4.8, 4.5, 4.4, 4.2, 3.9, 3.5, 2.6 and <0.05 for Human hair, Suri alpaca, Mohair, Vicuna, Llama hair, Merino and Carpet wool, Huacaya alpaca, Camel hair, Cashmere, and non-animal fibers, respectively. The survey and post training examinations indicated that trainees have gained solid technical skills and advanced knowledge of specialty animal fiber characteristics, and performed with a high accuracy in identification of animal fibres of different species and substitute materials.