ABSTRACT
A membrane condenser (MC) is a novel membrane separation technology that utilizes the hydrophobic nature of porous membranes to capture water vapor from humid gas. Factors such as temperature, pressure, flow rate, and gas composition entering the membrane condenser play a crucial role in water recovery efficiency. This study utilized hydrophobic polytetrafluoroethylene (PTFE) hollow fiber membranes to create multiple identical membrane modules. This research investigated the impact of temperature, flow rate, pressure on the intake side, gas flow on the cooling side, membrane area, and other variables on the performance of the membrane condenser process. This study compared water extraction efficiency under different conditions, focusing on feed flow temperature and sweeping flow. Results showed that at a temperature of 60 °C, the water recovery rate was 24.7%, while a sweep gas flow rate of 4 L/min resulted in a recovery rate of 22.7%. The efficiency of the membrane condenser decreased with higher feed flow rates but increased with larger membrane areas. A proportional relationship between inlet flow and membrane area was observed, suggesting an optimal range of 0.51-0.67 cm/s for both parameters. These findings offer valuable insights for the practical implementation of hydrophobic membrane-based membrane condenser technology.
ABSTRACT
OBJECTIVES: To determine the prevalence and distribution of hepatitis B virus (HBV) infection in Mianyang. METHODS: Data were extracted from the 12th five-year National Science and Technology Major Projects-Integrated Prevention and Control of Major Infectious Diseases in Mianyang. A two-level logistic regression model was established to determine factors associated with HBV infection. RESULTS: About 4.91% of people in Mianyang were HBsAg positive, which increased with age. HBV infection showed aggregation at townships. Governmental spending ≥¥1 000 000 on public health was a protective factor in the regression model; whereas, age, male gender, medical workers, absent from HBV vaccination, more than 80 g/d alcohol consumption were risk factors of HBV infection. CONCLUSIONS: Mianyang had medium level of HBV infections. But high HBV prevalence can be found in some townships. The known behavior risk factors all exist in Mianyang, which can serve as a screening tool for identifying high risk populations.
