Background: Egg yolk is the main cryoprotectant agent in semen freezing extenders which is used in order to protect spermatozoa against cold shock. However, elimination of animal bioproducts from the cryopreservation protocol is becoming mandatory. Therefore, the aim of this study is to compare a previously studied, homemade soya bean lecithin based extender with a commercially available extender for ram sperm cryopreservation. Materials and Methods: Samples from three rams were pooled and split into two equal aliquots and diluted (1:20) with i%lecithin - 7%glycerol (L1G7) and Bioxcell®. The effects of L1G7 and Bioxcell® on sperm parameters and the in vitro fertilization ability of frozen-thawed ram spermatozoa were assessed. Results: The results of this study revealed no difference between the two extenders in terms of motility, viability, and capacitation status. The results of in vitro fertilization in terms of rate of blastocyst formation were similar for both extenders, but significantly lower than that of freshly processed ram sperm. Conclusion: We conclude that both extenders are suitable for ram sperm cryopreservation.

The surface coating potentials of indigenous Nigerian clay from Umunze, Orumba South Local Government Area in Anambra state were assessed in screeding paints as part of the effort to provide sustainable materials for the coating industries. The clay samples were washed, sedimented, dried, grinded, and sieved to 80 μm, and analyzed using Energy Dispersive X-ray Fluorescence, X-ray diffraction spectrometry, and scanning electron microscope. The EDXRF results shows a high percentage of Nibioum (Nb), Silica Oxide (SiO2), and Iron (III) Oxide (Fe2O3) with 16.80%, 15.58%, and 6.60% respectively. Other chemical components like Lead (Pb), Barium (Ba), Zinc (Zn), Nickel (Ni), and Gallium (Ga) were present in very small quantities in the clay gotten from Umunze, meaning that the presence of these metals is too insignificant to cause damages to humans and the environment. Meanwhile, XRD shows very high percentage of Aluminum (Al2) and Silica (SiO2) in Umunze clay. This indicated that the crystalline structure of the uncalcined clay obtained from Umunze is kaolinite, with chemical formula given as Al2Si2O9. The surface morphology presented the clay particles to be clogged, thus showing that the umunze clay is desired for multiple clay purposes. The formulated screeding paint from the calcined clay of 750 °C gave a better paint than the 450 °C via these physical properties of parameters mentioned below. The 750 °C calcined screeding paint has its refractive index determined at 2.71 (PL= 1.5-9), viscosity was determined at 2039.8 (PL= 2000-3000), and durability was determined at 70% (PL=68- 98 %) and thereby, making it a better substitution as paint pigment-extender than that of 450 °C calcined screeding paint. The work revealed a better temperature performance of the sample, such that the produced sample can withstand temperature up to 320 °C before it will start deforming. Hence the clay can be used for ceramics.

The current study was conducted to see the effects of ascorbic acid supplementation into tris-citric acidglycerol-yolk (TCGY) extender and comparing it with Triladyl extender for bovine semen cryopreservation. Semen was collected from Sahiwal bulls for three weeks and each ejaculate (N=30) was divided into three aliquots. The first aliquot was extended using TCGY extender (control group), the 2 nd aliquot was extended using TCGY supplemented with 2. 1 mg/mL of ascorbic acid (AA group) and the 3 rd aliquot of the same ejaculate was extended using Triladyl extender (TA group). Following the processing and freezing, thawed semen straws from each treatment were evaluated for sperm motility, viability, acrosome integrity and live/dead ratio. The average path velocity was the highest in TA group (77. 99±, 2. 99 µ, m/s) compared with other two groups (P<0. 05). Similarly, values of total motility showed that TA group was superior to the other two groups (93. 6±, 0. 94% in TA versus 83. 33±, 1. 71% in control and 88. 53±, 1. 38% in AA group) (P<0. 05). The amplitude of lateral head displacement (8. 47±, 0. 27 µ, m versus 5. 00±, 0. 22 µ, m and 4. 74±, 0. 13 µ, m), length of the average path (50. 23±, 1. 79 µ, m vs. 25. 33±, 2. 12 µ, m and 23. 51±, 0. 39 µ, m), length of the curvilinear path (85. 01±, 3. 03 µ, m vs. 38. 89±, 1. 48 µ, m and 38. 65±, 0. 77 µ, m), length of the straight-line path (37. 28±, 1. 33 µ, m vs. 19. 39±, 0. 84 µ, m and 20. 42±, 0. 29 µ, m) and track speed (130. 93±, 5. 33 µ, m/s vs. 89. 13±, 3. 47 µ, m/s and 92. 11±, 1. 88 µ, m/s) were significantly higher (P<0. 05) in AA group as compared to TA and control group. Values for plasma membrane integrity (PMI), acrosome membrane integrity (AMI) and eosin were higher in AA and TA groups than in the control group (P<0. 05). The addition of ascorbic acid in TCGY extender can serve as a better alternative to commercial extender for cryopreservation of semen.

The effects of chain extender length on the gas permeability of polyether-based polyurethanes were investigated. Synthesized polyurethanes were based on 1000 and 2000 molecular weight polytetramethylene-glycol (PTMG) with toluene diisocyanate (TDI). Ethylene glycol, 1,4-butane diol (BDO), 1,6-hexane diol (HDO) and 1,10-decane diol (DDO) chain extenders were used to complete the conversion of prepolymers to the final polyurethanes. Membranes made from polyurethane were used to study the permeability and diffusivity of nitrogen, oxygen, methane, and carbon dioxide.Lag time method was used to determine the diffusivity of gases in polyurethanes. This study indicated that glass transition temperature of the polymers decrease by chain extender's length. The increase in chain extender's length makes the phase separation more probable. DSC and FTIR studies also indicate the extent of the phase separation in polyurethanes. Permeability and diffusivity of gases increase with the increasing length of the chain extenders. Selectivity of CO2/N2 changed by chain extender length, while selectivity of CO2/CH4 and O2/N2 did not show any remarkable changes. This study shows that solubilization is the dominant mechanism in gas permeation process in polyurethane membranes.