The combined toxicity test of polyester and tetra ethylene glycol on Daphnia magna

The combined toxicity test of polyester and tetra ethylene glycol on Daphnia magna. Globally, wide use of plastics and its increased production has led to a mounting amount of plastic waste entering the natural ecosystems. Due to their small size, plastic particles might be ingested by organisms at the lower end of the food chain and can be transferred by feeding to top consumers. Consequently, plastic pollution in aquatic environments and its potential impact on aquatic life has recently been recognized as an issue of considerable concern for ecosystem. I produced microplastics from 100% polyester thread from Houjix, cut it finely and used a dissecting needle to cut into a size of 5mm or less through a microscope. I also included ethylene glycol to investigate its toxic effects on D. magna. Since my aim was also to compare the toxicity effect of both chemicals, I used different concentrations individually and then in combinations to determine the potential toxic effects of polyester and tetra ethylene glycol (combined and separately) on the life (survival, death) of D. magna. Microplastics from 100% polyester thread from Houjix were produced, into a size of 5mm or less through a microscope. Tetra ethylene glycol was also used to investigate its toxic effects on D. magna. The toxicity effect of both chemicals using different concentrations individually and then in combinations were employed to determine the potential toxic effects of polyester and tetra ethylene glycol (combined and separately) on the life of D. magna. The study exhibited that the IC50 of TEG was higher as compared to polyester which suggests that polyester was more ad- verse than TEG. Moreover, when TEG and polyester were treated in combination, IC50 value was lower (Figure 3) than the IC50 value of TEG and polyester separately. In other words, the TEG and polyester in combination exhibited the lowest IC50 value in this study. These results suggest that TEG and polyester in combination had adverse effects on the growth and development of D. magna. Keywords: toxicity, microplastic, organic solvent, tetra ethylene glycol, Daphnia magna, polyester

Seam Quality: Experimental and Modelling Works using the Structural Equation Methodology

Seam quality in terms ofappearance and strength were investigatedfor very light weight fabrics (weight less than 80 g m"). Seams were constructed with different sewing parameters, which included types ofthread, stitch densities and needle size. Before constructing the seam for appearance and strength evaluation the mechanical properties of all fabrics were determined. The mechanical properties of 48 fabrics were determined using the Kawabata Evaluation System (KES-F), the Fabric Assurance Simple Test (FAST) and an Instron Tensile Tester. Evaluation ofseam quality was performed with respect to all the sewingparameters and the seams were ranked accordingly. The same evaluation ranking for seam appearance and strength was used for further analysis using Structural Equation Modelling (SEM) under AMOS. SEM was used to establish the relationship between seam quality with respect to appearance andstrength, andfabric mechanical properties. SEM was adopted to perform confirmative analysis to identify the fabrics mechanical properties that influence seam quality. From the experimental work, it was established that seams constructed with 100 % spun polyester thread with a ticket number of75gave the best ranking in terms ofseam strength. This threadperformedat optimum values when used with 6.5 stitches per centimetre (spcm) with a Metric needle size (Nm) of 90. For seam appearance, 100 % spun polyester with a ticket number of120 and Metric needle size of80 gave the best ranking. SEM established that extensibility and shear were the main fabric mechanical properties that determine seam quality ofvery light weight fabrics.

The transport of 3H and 14C in phloem strands of Heracleum lanatum and polyester threads

Experiments are described which show a great similarity in the profiles of rapid movement of tritium after external application of 3H2O to a small segment of a phloem strand of Heracleum lanatum and a water-soaked polyester thread. Efflux of rapidly transported tritium from phloem strands and polyester threads was also similar. No rapid movement of radioisotope from [U-14C]sucrose, [6,6′-3H]sucrose, or [6-3H]glucose along phloem strands was observed. A possible explanation for the rapid movement of tritium in terms of proton transfer is offered. It is concluded that the rapid movement of tritium in a phloem strand which occurs when 3H2O is applied externally to a segment is an artifact and that no normal translocation is occurring.