Microalgae, in wet conditions, tend to grow on surfaces and form biofilms. The adhesion of microalgae to surfaces is very important for algal mass culture. The formation and development of microalgal biofims are in large denpend on the properties of cell surface, substratum surface and gowth medium. In this paper, the influence of substratum surface zeta potential on the microalgal biofilms was particularly investigated. We focused on a widely-used microalgal strain, the freshwater autotrophic Chlorella sp..The adhesion phenomena of Chlorella sp. to surfaces with different zeta potential were observed microscopically. It was found that Chlorella sp. adhered easily to the surface with a positive zeta potential and difficultly to the surface with a negative zeta potential. We concluded that the surface zeta potential had a greater influence on the adhesion of microalgal cells to substratum surfaces. Our findings have important implications for microalgae mass culture and harvesting.

Rheological properties of microalgae suspensions affect the mixing and mass transport in photobioreactor systems and the design of downstream biomass processing technologies，and directly impact the energy demand and system performance of algae biofuel production. The purpose of this paper is to obtain the rheological properties as a function of volume fraction. The volume fractions of microalgae suspensions φ were derived according to the size distribution of the microalgae cells and cell number concentrations per cubic meter liquid. We found that at low concentrations, microalgae suspensions display a Newtonian fluid behavior. At high concentrations, microalgae suspensions behave as a shear thinning non-Newtonian fluid. The results are of potential scientific relevance and also useful in relation to the design of algae bioprocessing for the large scale production of economic biofuels.

To evaluate the efficacy and safety of solifenacin in the treatment of bladder spasms after urethroplasty. Patients underwent urethroplasty were randomly assigned to the study group (n = 165) and the control group (n = 150). Patients in the study group were treated with solifenacin for 7 days. Patients in the control group were placebo. Each group was further divided into four subgroups: paracentetic suprapubic cystostomy subgroup, traditional suprapubic cystostomy subgroup, former suprapubic cystostomy subgroup, and urethral catheter subgroup. A visual analogue scale (VAS) was used to measure the severity of bladder spasms. The mean duration of spasms, the frequency of spasms, and the incidences of urine extravasation and radiating pain were recorded each day. There were no significant differences in the VAS scores and mean duration of bladder spasms between the study and control groups . However, there was a significantly lower VAS score in the patients taking solifenacin in the paracentetic suprapubic cystostomy subgroup (p < .05). A similar tendency was noted in the mean duration of bladder spasms in this subgroup. In a comparison of the daily and nightly frequency of spasms within the four subgroups, a significant improvement was noted in the control group within 5 days. A similar difference was not noted within 6 days in the study group. The short-term therapy with solifenacin is an effective and safe method for decreasing the frequency of bladder spasms after urethroplasty. Patients undergoing paracentetic suprapubic cystostomy might be the only subset to benefit from this treatment.

The coal gasification syngas cooler is important for recovering the sensible heat generated during coal gasification. The ash layer formed on the heat transfer surface can seriously decrease the heat exchange efficiency. Establishing the initial layer is a prerequisite for massive ash deposition and will accelerate the accumulation of the ash and slag particles. In this study, numerical simulations are conducted to analyze the behavior of ash particles in large-scale industrial equipment. The deposition characteristics during the initial fouling and slagging stage in RSC are explored. The results show that in this stage, ash or slag particles mainly stick on the side wall, and only small particles deposit on the upper cone. The surface energy is the dominant factor influencing the composition of the initial layer. The adhesion ratio of FeS2 and ZnS particles is over ten times higher than that of SiO2 particles. With the decrease of the inlet flow rate and the increase of the inlet swirl velocity, the location corresponding to the maximum deposition proportion moves upward, and the local maximum deposition proportion increases.