A series of HPW/Zn-Ti layered double hydroxides (LDHs) were prepared by immobilizing phosphotungstic acid (HPW) on the Zn-Ti LDHs. Systematically characterizations were performed to elucidate their structure. These HPW/Zn-Ti LDHs hybrids were used as heterogeneous catalysts in the epoxidation of fatty acid methyl ester (FAMEs) with H2O2. The HPW/Zn-Ti LDHs showed higher activity than bulk HPW and Zn-Ti LDHs. The conversion of FAMEs and the selectivity to epoxy fatty acid methyl ester (EFAME) were up to 90.6 and 86.0%, respectively. (PO4[WO2(O2)]4)3- was presumed to be the active site for the epoxidation in this work. The formed oxygen-donating intermediate Ti-OOH transferred oxygen free radicals to (PO4[WO2(O2)]4)3- in the catalytic process, accelerating the transfer of oxygen free radicals. Therefore, high catalytic activity of HPW/Zn-Ti LDHs is related to the potential synergistic interactions of Ti-OOH and PW anions.

The present study was carried out on a number of 16 skulls of adult male domestic donkeys. Craniometric measurements for 40 different parts of the skulls were made. All investigated features were expressed as Mean±SD. Cephalic indices and ratios were calculated by using the investigated features. The craniometric measurements and cephalic indices had been compared with those of local horses and ponies. A skull length of 443.07±53.57 mm and a maximum zygomatic width of 169.09±17.64 mm were obtained. The size of donkey skull was between those of local horses and ponies. A skull index of 38.23±0.85, a cranial index of 45.01±2.83 and a facial index of 67.80±3.79 were obtained. Cranial index and skull index were found to be close in value to that of local horses and ponies. The results of this study revealed that donkey had a longer nose than local horse and pony, and the difference of skull length in the three species accounted for the facial length difference.

Se realizó un estudio sobre una serie de 16 cráneos pertenecientes a burros domésticos adultos, de sexo masculino. Se hicieron mediciones craneométricas en 40 partes diferentes de las muestras. Todas las características investigadas se expresaron como media ± desviación estándar, calculándose índices y proporciones cefálicas. Se compararon las mediciones craneométricas e índices cefálicos con los de caballos y ponis de la zona. La longitud del cráneo obtenida fue de 443,07±53,57 mm, con una anchura máxima del hueso cigomático de 169,09±17,64 mm. El tamaño del cráneo del burro se ubicó entre el de los caballos y los ponis locales. Se obtuvo un índice de cráneo de 38,23±0,85, un índice craneal de 45,01±2,83 y un índice facial de 67,80±3,79. Los índices craneal y de cráneo encontrados fueron cercanos a los valores correspondientes a los caballos y ponis locales. Los resultados de este estudio revelaron que el burro tenía una nariz más larga que el caballo y el poni. Además, la diferencia en longitud del cráneo en las tres especies representa la diferencia de longitud facial.