Expression signature of some immunity genes triggered in Apis mellifera carpatica model by Pseudomonas entomophila experimental infection.

Herein we report the expression profiles of certain immunity genes from Apis mellifera carpatica worker individuals experimentally infected with Pseudomonas entomophila L48 strain. Changes of the relative expression of abaecin, Relish, dorsal, Toll-1, domeless, and Duox genes were monitored by qRT-PCR. Our results were compared with similar ones from Drosophila melanogaster model and suggest that these genes are involved in the anti-infective defense mechanisms. Our study opens investigation avenues for modern prophylactic and therapeutic approaches of infections affecting the honeybees, but also for identifying new orthologous genes involved in the human innate immune response.

Effects of Pseudomonas aeruginosa infection on the expression profile of transient receptor potential-like (TRPL) gene from Drosophila melanogaster.

In an endeavor to monitor the effects of experimental infections with Pseudomonas aeruginosa on gene expression profiles of the eukaryotic model host, we focused on transient receptor potential-like (trpl) pleiotropic gene of Drosophila melanogaster (the fruit fly). Herein we report qRT-PCR data derived from experimental infections of male fruit flies with different genetic backgrounds by pricking and ingesta procedures, as compared to previous results obtained by microarray technology consecutive to ingesta experiments. Whenever statistically significant, the qRT-PCR results obtained for the whole body and intestine of Oregon wild-type flies infected with P. aeruginosa are in agreement with the microarray ones. Both expression profiling technologies revealed similar values of downregulation, supporting the robustness of trpl as a novel gene model for inquiring hostpathogen interactions. On the other hand, the downregulation of trpl in gammaCop mutant males is not confirmed by qRT-PCR data, suggesting that this mutant background is more sensitive to environmental and experimental conditions.

Novel Carbon Fibre Composite Centrifugal Impeller Design, Numerical Analysis, Manufacturing and Experimental Evaluations.

This paper presents an experimental investigation on using high strength-to-weight composite materials to reduce the mass of a centrifugal compressor impeller by 600%. By reducing the blades number from 17 to 7 and by doubling their thickness, the compression ratio and efficiency were maintained close to the reference metallic impeller. Using autoclave technology, seven composite blades were manufactured individually and assembled to form the impeller. After manufacturing, small deviations were found at the blade's tip. As these deviations were found to be symmetrical, impeller balancing was successfully performed removing a total of 45 g of mass, followed by an experimental test on a dedicated test bench. Experimental testing identified the resonant frequencies of the composite centrifugal impeller at 13.43 Hz 805 rot/min and at 77 Hz with a 0.1 mm/s amplitude at 4400 rot/min, highlighting feasibility and the advantage of a composite compressor impeller design with application in centrifugal compressors and rotating machine assemblies and sub-assemblies. As there are numerous numerical investigations performed on the strength analysis and on the lay-up orientations mechanical behaviour for polymer composite materials with respect to the design of centrifugal impellers, no experimental evaluations in relevant working conditions have been performed to date. As the paper contains relevant experimental data on the subject, the outcome of the paper may aid the oil and gas or aviation industries.

A Study on Using the Additive Manufacturing Process for the Development of a Closed Pump Impeller for Mechanically Pumped Fluid Loop Systems.

The efficiency of a centrifugal pump for mechanical pump fluid loops, apart from the design, relies on the performance of the closed impeller which is linked to the manufacturing process in terms of dimensional accuracy and the surface quality. Therefore, the activities of this paper were focused on defining the manufacturing process of a closed impeller using the additive manufacturing technology for mechanically pumped fluid loop (MPFL) systems in space applications. Different building orientations were studied to fabricate three closed impellers using selective laser melting technology and were subjected to dimensional accuracy and surface quality evaluations in order to identify the optimal building orientation. The material used for the closed impeller is Inconel 625. The results showed that both geometrical stability and roughness were improved as the building orientation increased, however, the blade thickness presented small deviations, close to imposed values. Finishing processes for inaccessible areas presented significant results in terms of roughness, nevertheless, the process can be further improved. Abrasive flow machining (AFM) post-processing operations have been considered and the results show major improvements in surface quality. Thus, important steps were made towards the development of complex structural components, consequently increasing the technological readiness level of the additive manufacturing process for space applications.

Manufacturing of Closed Impeller for Mechanically Pump Fluid Loop Systems Using Selective Laser Melting Additive Manufacturing Technology.

In the space industry, the market demand for high-pressure mechanically pumped fluid loop (MPFL) systems has increased the interest for integrating advanced technologies in the manufacturing process of critical components with complex geometries. The conventional manufacturing process of a closed impeller encounters different technical challenges, but using additive manufacturing (AM) technology, the small component is printed, fulfilling the quality requirements. This paper presents the Laser Powder Bed Fusion (LPBF) process of a closed impeller designed for a centrifugal pump integrated in an MPFL system with the objective of defining a complete manufacturing process. A set of three closed impellers was manufactured, and each closed impeller was subjected to dimensional accuracy analysis, before and after applying an iterative finishing process for the internal surface area. One of the impellers was validated through non-destructive testing (NDT) activities, and finally, a preliminary balancing was performed for the G2.5 class. The process setup (building orientation and support structure) defined in the current study for a pre-existing geometry of the closed impeller takes full advantages of LPBF technology and represents an important step in the development of complex structural components, increasing the technological readiness level of the AM process for space applications.