Numerical and experimental study on wind environment at near tower region of a bridge deck.

The Large Eddy Simulation (LES) turbulence model was used to investigate the wind environment over the deck near bridge tower and was verified using the wind tunnel tests. Compared with the wind tunnel tests, the computational fluid dynamics (CFD) approach was more convenient for the investigations of the local wind field. It was found that the influence of bridge tower on the wind flow can increase rapidly the wind speed on vehicles while bearing off a narrow zone near the tower. The dangerous situation can be effectively compromised by installing a proper local windshield barrier (WSB) with varying heights and porosity ratios along the bridge span. The length of the influence region of tower on the wind environment over the bridge deck was about 7 times of the tower width, implying a proper length of local windshield barriers on each side of the tower. Parametric studies demonstrated that the length of local WSB with different porosity ratios could affect the slope of equivalent wind speeds, indicating that the shorter the length of local WSB was, the rapider the wind speed of the tower influence region varied.

Using magnetic materials to harvest microalgal biomass: evaluation of harvesting and detachment efficiency.

Using naked iron oxide (Fe3O4) and yttrium iron oxide (Y3Fe5O12) nanoparticles as flocculants, the harvesting efficiency of Chlorella vulgaris biomass was investigated. The harvesting process includes two steps, which are the separation of microalgae from the culture solution with the magnetic nanoparticles and then the separation of the algae from the magnetic nanoparticles. The optimal dosages and pH values for the magnetic harvesting of microalgal biomass were determined. Results showed that Y3Fe5O12 nanoparticles were more efficient in microalgal biomass harvesting than Fe3O4 nanoparticles. In an effort to achieve more than 90% of harvesting efficiency, optimal dosages for Fe3O4 and Y3Fe5O12 to harvest microalgal biomass were 10 and 2.5 g/L, while the appropriate pH values were 6.2 and 7.3, respectively. The harvesting efficiency of Fe3O4 and Y3Fe5O12 nanoparticles increased as the pH value decreased. The experimental results also showed that under a higher pH value Fe3O4 nanoparticles were much easier to be separated from the flocs than Y3Fe5O12. 62.9% of Fe3O4 nanoparticles could be de-attached from the aggregates, when the floc pH value reached 12.3.

Characteristics and formation of typical winter haze in Handan, one of the most polluted cities in China.

Handan, a city within the North China Plain (NCP) region, is a typical city influenced by regional particulate matter (PM) pollution. One-year hourly semi-continuous observation was carried out in 2015 in Handan with the aim of identifying the chemical composition and variations in PM2.5. Moreover, the concentration of aerosol precursors, meteorological factors, and secondary transformations are considered. The results demonstrate that the annual average PM2.5 concentration in Handan is 122.35µgm-3, approximately 3.5 times higher than the Chinese National Ambient Air Quality Standard (NAAQS) (35µgm-3), and only 12days were below the guideline. As expected, PM concentrations are highest in winter, especially in December. In addition, we measure the concentrations of five species commonly found in PM, nitrate, sulfate, ammonium, inorganic carbon, and organic carbon. Of these, nitrate and sulfate account for the largest proportion of PM2.5; during periods when the PM2.5 concentration was below 400µgm-3, nitrate dominates, while above this concentration, sulfate dominate. This is likely related to the nitrogen and sulfur oxidation ratios, which are in turn, especially the sulfur oxidation ratio, driven by high relative humidity (>60%). In addition, haze events are driven by other meteorological conditions, wind speed and direction, where low wind speeds from the south and southwest enable pollutant accumulation, which are infrequently interspersed with brief periods with high wind speeds that promote pollutant dispersal. Even though Handan is among the ten most polluted cities in China with regard to air pollution, few studies beyond model simulations have analyzed air pollutant concentrations in this city. Therefore, this study makes a significant contribution to understanding air pollution in Handan, which can further be used to improve our understanding of regional pollution in the highly populated North China Plain. These results have implications for the creation of policies and legislation, as well as other pollution control measures.

Cultivation of Chlorella sp. with livestock waste compost for lipid production.

Cultivation of microalgae Chlorella sp. with livestock waste compost as an alternative nutrient source was investigated in this present study. Five culture media with different nutrient concentrations were prepared. The characteristics of algal growth and lipid production were examined. The results showed that the specific growth rate together with biomass and lipid productivities was different among all the cultures. As the initial nutrient concentration decreased, the lipid content of Chlorella sp. increased. The variations in lipid productivity of Chlorella sp. among all the cultures were mainly due to the deviations in biomass productivity. The livestock waste compost medium with 2000mgL-1COD provided an optimal nutrient concentration for Chlorella sp. cultivation, where the highest productivities of biomass (288.84mgL-1day-1) and lipid (104.89mgL-1day-1) were presented.

Strategies for Lipid Production Improvement in Microalgae as a Biodiesel Feedstock.

In response to the energy crisis, global warming, and climate changes, microalgae have received a great deal of attention as a biofuel feedstock. Due to a high lipid content in microalgal cells, microalgae present as a promising alternative source for the production of biodiesel. Environmental and culturing condition variations can alter lipid production as well as chemical compositions of microalgae. Therefore, application of the strategies to activate lipid accumulation opens the door for lipid overproduction in microalgae. Until now, many original studies regarding the approaches for enhanced microalgal lipid production have been reported in an effort to push forward the production of microalgal biodiesel. However, the current literature demonstrates fragmented information available regarding the strategies for lipid production improvement. From the systematic point of view, the review highlights the main approaches for microalgal lipid accumulation induction to expedite the application of microalgal biodiesel as an alternative to fossil diesel for sustainable environment. Of the several strategies discussed, the one that is most commonly applied is the design of nutrient (e.g., nitrogen, phosphorus, and sulfur) starvation or limitation. Other viable approaches such as light intensity, temperature, carbon dioxide, salinity stress, and metal influence can also achieve enhanced microalgal lipid production.

Analysis of drug resistance-associated proteins expressions of patients with the recurrent of acute leukemia via protein microarray technology.

INTRODUCTION: To detect the expressions of drug-resistance related proteins in bone marrow mononuclear cells of acute leukemia (AL) patients using protein microarray and to analyze the clinical value of protein microarray in predicting prognosis of AL patients. PATIENTS AND METHODS: A total of 48 AL patients received chemotherapy were divided into four groups: recurrent acute myeloid leukemia group (R-AML; n=15); AML continue remission group (AML-CR; n = 13); recurrent acute lymphocytic leukemia group (R-ALL; n=13); and ALL-CR group (n=7). Fifteen age-matched patients with non-hematologic disease were used as controls. RESULTS: Expression levels of P-gp, LRP/MVP, BCL-2, GST-π, PCNA, CXCR4 were increased significantly in both AML-R and ALL-R groups (p < 0.05). Besides, LFA-1 and TRAIL-R were also up-expressed significantly in ALL-R group (p < 0.05). In addition, the levels of P-gp, GST-π expressed in AML-R group were higher than those in AML-CR group (p < 0.05) and P-gp, LRP/MVP, GST-π, LFA-1 and CXCR4 in ALL-R were expressed higher than those in ALL-CR group (p < 0.05). CONCLUSIONS: The recurrent of AL were related closely to the over expression of drug resistance-related proteins. Protein microarray can be used in the prediction of AL recurrence and would be beneficial in guiding individual therapy and patient prognosis.

Recycling harvest water to cultivate Chlorella zofingiensis under nutrient limitation for biodiesel production.

Harvest water recycling for Chlorella zofingiensis re-cultivation under nutrient limitation was investigated. Using 100% harvest water, four cultures were prepared: Full medium, P-limited medium, N-limited medium and N- and P-limited medium, while another full medium was also prepared using 50% harvest water. The results showed that the specific growth rate and biomass productivity ranged from 0.289 to 0.403 day(-1) and 86.30 to 266.66 mg L(-1) day(-1), respectively. Nutrient-limited cultures witnessed much higher lipid content (41.21-46.21% of dry weight) than nutrient-full cultures (26% of dry weight). The N- and P-limited medium observed the highest FAME yield at 10.95% of dry weight, while the N-limited culture and P-limited culture shared the highest biodiesel productivity at 20.66 and 19.91 mg L(-1) day(-1), respectively. The experiment on harvest water recycling times demonstrated that 100% of the harvest water could be recycled twice with the addition of sufficient nutrients.