Could the Storage Time Post-collection Affect the Post-thaw Motility and Fertilizing Ability of Mediterranean Brown Trout Semen?

The aim of this study was to evaluate the effect of different cool storage time intervals between collection and semen freezing on both fresh and cryopreserved semen motility parameters and the post-thaw fertilizing ability of Mediterranean brown trout semen. The ejaculates were split into six aliquots and stored on ice for 1 to 6 hours, until freezing. Fresh and post-thawing sperm motility were evaluated by Computer-Assisted Sperm Analysis system, whilst the fertilizing ability was assessed by in vivo trials. In fresh semen, at 3 h of storage, a significant decrease of total motility, linear movement (STR, LIN) and beat cross frequency was recorded, whilst the amplitude of lateral displacement of the spermatozoon head underwent a significant increase. Velocity parameters (VCL, VAP and VSL) were not affected by the cold storage time, whilst the duration of sperm movement was significantly higher at 1h compared to the other times tested. Freezing procedure overall decreased almost all post-thaw sperm motility parameters, however no significant differences was observed over time, both in term of fast and linear movement. Cool storage time did not significantly affect the percentage of post-thaw eyed embryos. Our results showed that Mediterranean brown trout semen can be stored on ice even up to 6 hours before freezing, without decreasing its post-thawing quality and fertilizing ability.

Reduced Pollination Efficiency Compromises Some Physicochemical Qualities in Gac (Momordica cochinchinensis Spreng.) Fruit

Gac is valued for the nutritious aril surrounding its seed. When pollinators are limited or when flower sex expression is female-biased, hand pollination is necessary. Here, female flowers were hand pollinated with male flowers or pollen stored for up to 84 days at 4 or −20 °C, and fruit set and some qualities of mature fruit were evaluated. Cool storage reduced pollen viability (germinability and pollen tube length) and compromised fruit set (10–87%) compared with fresh pollen (97%). Fruit weight was also reduced at least by 8%, and oil concentration in aril by 40%. However, the lycopene and β-carotene concentrations in aril were largely uncompromised, and some fruits were of a marketable weight (>1.2 kg) and quality. Cool storage is a low-cost method for the short-term storage of Gac pollen. However, methods for drying pollen to an inactive state need investigation for a storage protocol, and for improvements in fruit set and fruit physicochemical qualities using hand pollination.

Electrodeposition Patterned Copper Foam with Micro/Nanostructures for Reducing Supercooling in Water-Based Cool Storage Phase-Change Materials

Copper foam is widely used in industrial catalysis, flow boiling, and latent heat storage systems. It is expected that a multi-level topology copper foam with micro/nanostructures can further enhance performance. In this study, an electrochemically patterned copper foam with micro/nanostructures was fabricated and used to reduce supercooling in water-based cool storage phase-change materials. By controlling the reaction time (e.g., 195 s, 255 s, and 300 s), the pattern on the copper foam skeleton appeared as granular, dendritic, and coral-like structures, respectively. Compared with a blank group with supercooling of 11 °C during the solidification process, the unmodified copper foam (CF#0s) can reduce it to 7.7 °C. Electrodeposition-patterned copper foam with micro/nanostructures can further reduce supercooling. The average supercooling degree for CF#195s, CF#255s, and CF#300s was further reduced to 5.6 °C, 4.8 °C, and 4.6 °C, respectively. Among them, CF#300s reduced the supercooling and delay time by 60%. This occurred because the micro-nanostructure on the skeleton of copper foam provides abundant nucleation sites for the solidification of water, and surface roughness increases the nucleation rate.

Residential Air Conditioning System Integrated with Packed Bed Cool Storage Unit for Promoting Rooftop Solar PV Power Generation

The increase in the share of renewable-based power in the gross power generation in most countries causes significant concerns over the addition of renewable power with the grid, results in stability issues in most developed nations. Energy storage is an emerging technology that is considered the ultimate solution in developing microgrids with distributed renewable power generation. The cool thermal storage plays a vital role in economically promoting renewable power among different storage units. The major objective of the research work is to demonstrate the integration of residential air-conditioning systems with packed bed cool storage units to promote rooftop solar power generation for residential space cooling applications. In order to achieve the said objective, an experimental investigation was made to study the charging/discharging characteristics of a packed bed cool-storage unit combined with a chiller and a cooling coil unit suitable for small capacity air-conditioning applications. The system consists of encapsulated spherical capsules filled with a phase change material blended with distilled water and pseudomonas (nucleating agent) and the heat transfer fluid as a combination of distilled water and Mono-ethylene glycol. A cooling coil unit was connected to the cool-storage tank to transfer cool energy from the storage tank to the space to be cooled when there is a demand. The important parameters, such as instantaneous and cumulative heat transfer during the charging/discharging processes, are presented. The average COP values of the chiller during the charging operation were estimated as 1, 0.93, and 0.89 when the HTF setpoint temperatures were -6°C, -9°C, and -12°C, which shows a decrease in performance as the setpoint temperature decreases. During the discharging process, a cooling load of 2.25 kW is obtained during the first cycle of operation and gradually reduces to 0.3 kW during the sixth cycle of operation. The increase in the HTF temperature during each cycle of operation indicates that the Phase Change Material (PCM) in the balls cannot release the heat as per the demand after a certain period of discharging. Hence, decreasing the internal thermal resistance by suitable measures is essential to achieve uniform heat flux and to operate the system successfully