Production of Fertilizer from Seawater with a Remote Control System

Seawater is abundant and full of nutrients known as ORMUS. Inorganic fertilizers have become scarce and expensive, so alternatives to feed plants are being studied. An automatic tank on a fishing boat was designed to extract salts from seawater, as follows: Sodium hydroxide is applied to seawater and agitated within a tank until its pH reaches 10.78. Salts begin to deposit, and the sodium mixed with the water stays at the surface. Water with sodium is removed after 3 h with a low-pressure pump. Clean water is added to the salty solution at the bottom of the tank to remove more sodium. Water at the top is sucked by the pump again, and the process is repeated once more. After the white salt (ORMUS) lying at the bottom of the tank is removed, the fertilization extraction process can start again. The automatic system regulates the agitator speed, pump filling and suction timing, and bottom valve opening.

Oil Pressure Monitoring for Sealing Failure Detection and Diagnosis of Power Transformer Bushing

Power transformer bushings withstand great electrical and mechanical stress during high voltage and high current working conditions. Sealing failure poses a great threat to the long-term and reliable operation of the bushing and power transformer; however, the criterion to evaluate the sealing status of a bushing caused by mechanical problems is still lacking. In this paper, a transformer bushing model is established to gain theoretical insight into the relationship between temperature and pressure of a compact multilayer bushing. To evaluate the bushing mechanical status, different sealing conditions are tested based on the temperature and pressure monitoring within the physical 110 kV bushing. The results show that mechanical sealing failure can be diagnosed when the fluctuation of the oil pressure value exceeds the theoretical curve in steady state by 3 kPa. With different reliability coefficients, gas leakage and oil leakage are available to be further determined. The primary and auxiliary criteria based on oil pressure and its gradient are proposed to evaluate comprehensively the actual sealing condition of the bushing, and a wireless oil pressure module is developed at the bottom valve, which is quite beneficial to field online application. It is promising to extend the online mechanical monitoring and diagnosis to oil-immersed power equipment.

Disruption of silicone valve housing in a Codman Hakim Precision valve with integrated Siphonguard

Authors of this report describe 2 patients who had undergone shunt insertion for hydrocephalus and who, at 6 weeks or 9 months after their last revision, presented with symptoms of shunt dysfunction and CSF collections at the valve site. At the ensuing shunt revision in both patients, the silicone housing was fractured and the Siphonguard was disconnected from the Codman Hakim Precision flat-bottom valve. The cause of these failures was not clear since manipulation, bending, and twisting of the valves were not thought to have occurred during implantation. A review of the FDA's Manufacturer and User Facility Device Experience (MAUDE) database revealed 58 cases of silicone housing failure in the Codman Hakim Precision valve with integrated Siphonguard since the year 2000. A single report was found in the databases administered by the Canadian Medical Devices Sentinel Network (CMDSNet). The Codman Hakim Precision valves with integrated Siphonguard are delicate devices that do not withstand the intraoperative handling tolerated by other valves. When these valves are implanted, gentle handling and wide exposures are needed to minimize the risk of valve damage. Valves should be handled according to the manufacturer's instructions. However, in light of this particular pattern of failure, it is recommended that the manufacturer redesign this valve to provide handling tolerance that is characteristic of other valves on the market. The featured cases illustrate the importance of the surgeon's role in postmarket surveillance of medical devices and reporting device failures to the responsible agencies and manufacturers.