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• A novel and disposable compliance pump was suggested and fabricated for supplying blood into a microfluidic channel. • Correction factor (β) was adopted for improving accuracy of fluid velocity obtained by micro-PIV technique. • A discrete fluidic circuit model was developed for obtaining flow rate and pressure in a microfluidic channel. • Four kinds of fluid property (i.e., fluidic resistance, viscosity, time constant, and compliance) was obtained by analyzing flow rate and pressure. • The proposed method was employed successfully to detect biophysical change in suspended blood. Blood viscosity is considered a promising indicator of cardiovascular disease and helps predict disease risks. However, conventional methods require two highly precise pumps to maintain consistent flow rates in co-flowing streams. In this study, a low-cost and disposable compliance pump was fabricated by inserting three components (a syringe needle, a blood-loaded syringe, and an air compliance unit [ACU]) into a three-way valve. Since the pump induces transient blood flow, accurately obtaining the transient flow rate is necessary. A correction factor was employed to improve the blood velocity obtained by microparticle image velocimetry. Air pressure inside the ACU was estimated using the ideal gas law. A discrete fluid circuit model was constructed to estimate the flow rate and pressure in a microfluidic channel. Four types of fluid physical properties (fluid resistance, fluid viscosity, time constant, and compliance coefficient) were obtained by analysing flow rate and pressure. The proposed method was employed to detect several types of suspended blood (variations in haematocrit, thermal-shocked RBCs, and RBC aggregation-enhanced blood). From the quantitative comparison, the proposed method provides better results than the previous method. Therefore, the proposed method is a promising tool for detecting biophysical variations in suspended blood. [Display omitted] [ABSTRACT FROM AUTHOR]

Coal fire sponges (CFSs) are a type of sponge-like contaminated soil bulge common in coal fire areas. However, the impacts of CFSs on the local environment are not yet understood. Thus, this study investigated soil samples from CFSs in the Wuda coalfield, Inner Mongolia, China, focusing on the acidity, sulfate, and fluorine content. The results showed that the CFSs were highly acidic, with an average pH of 0.76, and contained high levels of SO 4 2− (257.29 × 103 μg/g), total fluorine (TF, 2011.6 μg/g), and water-soluble fluorine (WF, 118.94 μg/g), significantly exceeding those in the regional background soil and indicating that CFSs are a point source of heavy pollution. Soils in the 8000 m2 reclamation zone showed elevated acidity and high SO 4 2− (129.6 × 103 μg/g), TF (1237.8 μg/g), and WF (43.05 μg/g) levels, which was likely the result of the weathering and dissemination of CFS. The CFS samples were rich in hydrogen fluoride, releasing 202.05 ppb of it when heated to 40 °C. Correlation analysis indicated that the acid sulfate soils in CFSs are likely caused by HSO 4 −/SO 4 2−. Time-of-flight secondary ion mass spectrometry detected four characteristic ions (F−, H 3 O+, H 2 SO 4 +, and HSO 4 −) in all micro-domains of each sample, indicating that ionic fluorine compounds and sulfuric acid hydrate were found in the CFS samples. Sulfate minerals detected in CFSs included CaSO 4 , Fe 2 (SO 4) 3 , CdSO 4 , NH 4 HSO 4 , and Na 2 SO 4. Thus, the results identified CFSs as a transmission channel for contamination, with erosional surface soils as the carrier, for the first time. CFSs pose a serious threat of contamination, albeit over limited areas. [Display omitted] • Coal fire sponges (CFSs) are found globally in soft soil above burning coal seams. • Samples compared CFSs with the local coalfield area and two reference sites. • High acidity, sulfate, and fluorine levels were detected in all CFS samples. • CFSs were confirmed as a source of environmental contamination. • Contamination from air deposition is wider, but CFS intensity is higher. [ABSTRACT FROM AUTHOR]