Corpos-de-prova de zircônia parcialmente estabilizada com ítria foram moldados por prensagem uniaxial, sinterizados e nitretados em plasma de micro-ondas à pressão atmosférica. A camada de ZrN sobre zircônia formou-se a uma taxa de 4 µm.min-1, podendo atingir uma espessura de 500 µm. As amostras foram caracterizadas por meio de medidas de dureza e resistência ao desgaste. A superfície nitretada apresentou dureza superior e resistência ao desgaste similar ao substrato de zircônia.

Samples of yttria partially-stabilized zirconia were molded by uniaxial pressing, sintered and nitrided in an atmospheric pressure microwave plasma. This procedure leads to the formation of a ZrN layer whose growth rate and thickness reached 4 µm.min-1 and 500 µm, respectively. The samples were characterized by means of hardness and wear resistance tests. The nitrided surface exhibits superior hardness and wear resistance similar to that of the zirconia substrate.

During the last decade there has been an increased demand for cyclamen as a potted ornamental plant in Mexico, but there is a deficit of high quality seed at low cost. The objective in this work was to investigate if there is any influence of the mother plants age on phenology, seed production and quality. The cv. Lugano Supreme special mix was used and plants were grown in a plastic greenhouse were air temperature varied between 5.4 and 34.0 °C, with an average of 17.8 °C. The treatments were three plant ages: one (T1), two (T2) and three (T3) years respectly. The phenological stages considered were: PS1: when floral button had a diameter from 1.0 to 2.0 mm, PS2, floral button with 2.0 to 3.0 cm of length, and PS3, initial flower opening. T2 had the fastest development time from PE1 to PE2, 30 days, statistically shorter than in the other treatments; from PE1 to PE3, it was 38, statistically similar to T1 with 42 days, and from PE1 to harvest it was of 120days, statistically similar to T3 (123 days). Regarding capsule setting, T1 was significantly superior (83%) to T3 (66%) but similar to T2 (75%). T3 and T2 had a seed yield (2.16 and 1.92 g·plant-1, respectively) superior to that of T1 (1.02 g·plant-1). Ratings for seed quality characteristics for all treatments were: germination, lower than 60%; viability, lower than 65%, and weight of 1000 seeds lower than 6 g. All of them below standards required for certification process.

En la última década en México se ha incrementado la demanda de ciclamen como planta ornamental, pero existe déficit de semilla barata de alta calidad. En este trabajo se estudió la influencia que tiene la edad de la planta madre sobre la producción y calidad de semillas de esta especie. Plantas de la variedad Lugano Supreme mezcla especial se sembraron en un invernadero con temperatura entre 5.4 y 34.0 con promedio de 17.8 °C. Los tratamientos consistieron en plantas de uno (T1), dos (T2) y tres años (T3) de edad. Las etapas fenológicas consideradas fueron: EF1, botón de 1.0 a 2.0 mm de diámetro; EF2, botón de 2.0 a 3.0 cm de longitud y EF3, apertura floral inicial. Las plantas del T2 tuvieron un desarrollo más rápido: entre EF1 y EF2 hubo 30 días, lo que es más corto estadísticamente que lo observado en los otros dos tratamientos; entre EF1 y EF3 fueron 38 días, estadísticamente similar al T1 (42 días), y de EF1 a cosecha fueron 120 días, estadísticamente similar a T3 (123 días). En prendimiento de cápsulas, el T1 (83%) fue significativamente superior a T3, 66.4%, pero similar a T2 (75%). T2 y T3 produjeron rendimientos de semilla superiores (1.93 y 2.16 g·planta-1). En cuanto a las características de calidad de semilla, en todos los tratamientos la germinación fue inferior a 60%, la viabilidad inferior a 65% y peso de 1000 semillas inferior a 6 g. Todos ellos por debajo de los estándares indicados para certificación.