Preservation of rapana meat by the irradiation technology

The article considers the technology of maturing preserves from the meat of the Black Sea gastropod mollusc Rapana thomasiana using irradiation technologies. The methods of improving the technology of processing rapana meat have been studied in order to ensure long-term storage of the finished product without using artificial preservatives. The technology is based on the preliminary preparation of the semi-finished product, which includes defrosting, sorting, cutting, washing, inspection, portioning, blanching, and cooling. It has been studied how different methods of preprocessing the raw material affect the mechanostructural properties of rapana preserves. Blanching the meat of rapana has proved practical. Acetic acid has been shown to increase the sensitivity of rapana muscle tissue to picowaves. It has been found effective to soften rapana muscle tissue by marinating with acetic acid and by using picowave irradiation in various doses (2 to 10 kGy) for 60 s. The choice of the recommended dose of 2 kGy has been substantiated. It has been established that after picowave processing, the sensory properties of the finished product do not change. The system of picowave processing of preserved meat to soften its inhomogeneous structure has been described. The shift of kinetic energy in the electronic field using thin targets to form the required radiation field of different sizes has been used. This has allowed influencing the inhomogeneous structure of the raw material. It has been proved that after picowave irradiation with the dose 2 kGy, the preserved rapana meat is microbiologically safe and can be stored for 90 days at 4±2°С. The technological scheme of making preserves from rapana meat using PWP has been provided. The studies indicate that using the irradiation technology is practical, as it ensures the maturation of low-maturing aquatic organisms, extends the shelf life of food, guarantees safety and high quality

Equal Channel Angular Pressing Consolidation and Heat Treatment of Blended Elemental Powders of Fe-Mn-Al

In this work, the consolidation of blended elemental powders of iron, manganese and aluminum (Fe-25Mn-15Al wt.%) was performed by Equal Channel Angular Pressing (ECAP). Samples were consolidated at room temperature in a Φ = 120° die by a single pass and a second pass in route A. Both samples were heat treated at 650 °C and water cooled. Prior to heat treatment, samples presented a dense but chemically inhomogeneous structure. Fe and Al particles were highly deformed, whereas, Mn was almost undeformed. Mn particles were partially shattered by friction with Fe and Al particles. After heat treatment, the samples were characterized by SEM-EDX and presented substantial interdiffusion along the particles interfaces. It is believed that higher deformations by ECAP may improve the sinterability of consolidated samples in order to densify and chemically homogenize it.

30 dB microstrip coupler with high directivity

Due to inhomogeneous structure of a microstrip directional couplers, i.e. partly dielectric substrate, partly air, they mostly present property of poor directivity and low coupling level. High directivity is achieved by a capacitive compensation by gap coupling of open stub formed in sub-coupled line. Neverthless, these couplers have advantage of easy fabrication, lightweight and incorporation with other microwave devices, and is validated via design using Sonnet software. The main goal was to obtain coupling around -30 dB, meaning that almost all power is passed to the output, with a wide band, from around 3.5GHz to nearly 9GHz. Desired values have been obtained, including isolation and input match reaching -70 dB.