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The cold spray (CS) process is the latest solid-state deposition method that has gained significant awareness for the metallization of polymer matrix composites (PMCs) materials to modify their surface properties, including electrical or thermal conductivity and electromagnetic shielding. In comparison with other coating processes, CS allows for the production of metallic coatings without the necessity to reach the melting temperature of the sprayed particles and provides a way to deposit resistant materials with improved properties onto various components to minimize wear, erosion and corrosion. For the first time in the literature, this work has the innovative goal of applying the life cycle assessment methodology to the case study of the CS production process in order to ascertain whether CS could be framed in the realm of green technologies offering interesting opportunities to improve manufacturing sustainability. In particular, the environmental impact of CS associated with the metallization process of PMCs was considered in terms of energy consumption and CO2, NOx and SO2 emissions, which are used as indicators in the life cycle assessment. When compared to different coating processes, the results suggest that CS has a large potential to reduce the environmental effects connected with the products in terms of the amount of CO2 and hazardous emissions created throughout the process. [ABSTRACT FROM AUTHOR]

The analysis of chromosome pairing during meiosis is important for understanding the relationships between different genomes. To evaluate the diversity of chromosome pairing behavior in the wild species of Roegneria sinica var. media Keng with St and H genomes in Triticeae (Poaceae), differences and similarities in the meiotic chromosome pairing behaviors of the two genomes in two populations of R. sinica var. media, were analyzed using genomic in situ hybridization. Chromosome pairing at meiotic metaphase I in the two populations of R. sinica var. media mainly formed bivalents, although several univalents, trivalents and quadrivalents also occurred. Chromosome pairings occurred mainly between homologous chromosomes. However, some non-homologous pairings were observed under natural conditions. No significant differences in karyotype were found between the St and H genomes. Chromosome pairing behaviors differed between and within the two populations. Genetic variation occurred mainly within populations (94.04 %), and variation was more abundant in one population than the other. The genomes St and H differed, but there was some relationship between the two genomes. These findings suggest that homoeologous pairing of chromosomes or exchanges occurred between different genomes of the wild species in Triticeae during evolution. The findings also provide conclusive cytological evidence for genetic variation within the wild species, which forms the basis of their genetic diversity. [ABSTRACT FROM AUTHOR]

Spindle membrane in the second division of meiosis in Iris comprises endoplasmic reticulum (ER) and small spherical vesicles (40-80 nm diameter). The vesicles are in all respects similar to those of dictyosomes and it is proposed that they originate in the Golgi system. ER on the other hand is generated from the nuclear envelope (NE). Invaginations and evaginations of the inner and outer membranes of the NE are present at interphase and they enlarge during prophase II and break to form spindle ER elements at the beginning of prometaphase II. The area enclosed by this ER continues to increase until the entire spindle is filled with irregular profiles at mid-prometaphase II. During late-prometaphase II the quantity of ER decreases and, concurrent with an increase in the number of microtubules (MTs), the cisternae align alongside MT bundles and accumulate at the poles. It is suggested that ER increases in quantity by growth of NE membranes. Furthermore, the alignment of ER along the interpolar axis and its transport polewards prior to anaphase suggest the action of a force on each ER element. [ABSTRACT FROM AUTHOR]

Some of results from morphological and cytological observations and esterase-isozyme studies of a rice-sorghum hybrid are presented in this paper. There is a great diversity of morphological characters and some special characteristics in the progenies of the hybrids of rice with sorghum. The meiosis of pollen mother cells in the early generations of the hybrid was found to be abnormal. One main band coinciding with one found in sorghum but lacking in rice appeared in the majority of the hybrid lines. This band is characteristic of a are the specificities of the distant hybridization of rice and sorghum, and is rarely observed in the intervariety hybrids or hybrids between subspecies of Oryza sativa, indica and japonica. On the basis of these facts we concluded that the hybrids obtained are true hybrids of rice and sorghum. [ABSTRACT FROM AUTHOR]