Preparation of solid organic fertilizer by co-hydrothermal carbonization of peanut residue and corn cob: A study on nutrient conversion.

With continuous recognition of green, organic and pollution-free products, the organic fertilizer plays an increasingly important role in agricultural production. Hydrothermal carbonization (HTC) is an efficient and environmentally friendly biomass treatment technology that can achieve value-added utilization of solid wastes. This study evaluated the potential of two typical agricultural and forestry wastes (corn cob and peanut residue) in preparing as solid organic fertilizers through HTC. The effects of reaction temperature, residence time, and the raw material composition on hydrochar yield, total nutrient content (TNC), nitrogen recovery, and nutrient elements transformation in HTC were investigated. Corn cob was proven to be not an ideal raw material for the preparation of organic fertilizers because of the low TNC and the high C/N ratio of its hydrochar. On the contrary, peanut residue was suitable for preparing organic fertilizers due to its high TNC and appropriate C/N ratio. The co-HTC of corn cob and peanut residue could further improve the N recovery rate from 8.52% (for peanut residue only) to 19.51% due to the synergistic effect between them. Under the optimal hydrothermal conditions of 240 °C, 120 min, and mixing ratio of 1:1, the hydrochar yield was as high as 27.86%, and the C/N value (11.98) and TNC (6.331%) were both appropriate as fertilizer. Furthermore, the potential migration and transformation paths of nutrients including N, P, K and metal elements in the co-HTC were analyzed. The thermodynamic conditions and raw materials composition significantly affect the migration and transformation of N, P and K between solid and liquid. N dissolved into process water (mainly ammonia) would migrate into hydrochar and bio-oil with increasing of reaction temperature. P was fixed in hydrochar through precipitation and adsorption reaction with metal ions. Further, adjusting pH or adding metal salts can promote the fixation of N and P in solid.

Fabrication and performance of a stable micro/nano composite electret filter for effective PM2.5 capture.

Airborne particulate matter (PM) pollution has raised serious concerns over both the global climate and public health. Therefore, there is an urgent need for air filters of high-efficiency and energy-saving. Pore structure optimization and electret enhancement are feasible means to improve their filtration performance. Herein, a novel sandwich-structured electret composite filter with a low pressure drop and robust filtration stability was successfully designed and fabricated. The composite filter was composed of fluffy PS microfibers with large electric resistivity and high porosity, and PAN nanofibers with high polarity and small pore size. Benefiting from the fluffy structure constructed by electrospinning at the right humidity, the tortuous pore channels created by the appropriate mixing of microfibers and nanofibers, and the abundant static charges generated by the hybrid of polar and nonpolar polymer materials, the PS/PAN/PS composite filter possessed a high filtration efficiency of 99.96% for particles of 0.30 µm, a low pressure drop of 54 Pa and a satisfactory quality factor value of 0.1449 Pa-1 at an airflow velocity of 5.3 cm/s. In particular, the composite filter exhibited better electret stability and PM2.5 loading performance than the commercial ones, which guarantees its long-term storage and usage.

Self-cleaning of Surfaces: the Role of Surface Wettability and Dust Types.

The self-cleaning property is usually connected to superhydrophobic surfaces (SHSs) where the dust particles can be easily removed by the rolling motion of droplets. It seems that superhydrophobicity (its durability is questionable nowadays) is a necessity. However here, it is disclosed that self-cleaning can also be realized on an ordinary surface by droplet impinging. The effects of surface wettability and the types of dust particles are considered. The self-cleaning is realized by two steps: (1) the pickup of particles by the water-air interface of an impinging droplet, (2) the release of the impinging droplets from the surface. It can be observed that only the trailing edges of the droplets can pick up particles when the droplets recoil from the inclined surfaces. The hydrophilic surface can also achieve self-cleaning under some conditions. This interesting finding may be helpful for the successful implementation of self-cleaning with common surfaces.

Statin therapy on glycaemic control in type 2 diabetes: a meta-analysis.

OBJECTIVE: Randomised controlled trials (RCTs) indicate that statin therapy has cardiovascular benefit among patients with type 2 diabetes. Recently, statins were reported to increase risk of diabetes by 9%. The aim was to investigate by a meta-analysis whether statins deteriorate glycaemic control in type 2 diabetes. METHODS: Medline, EMBASE and Cochrane Central Register of Controlled Trials from 1966 to 2012 were searched for RCTs of statins. Included were only trials with type 2 diabetes. MAIN OUTCOME MEASURES: The I(2) statistic was used to measure heterogeneity between trials and calculated mean differences for glycaemic parameters with random-effect meta-analysis. RESULTS: 26 eligible studies were identified with 3232 participants. Statin therapy had no remarkable influence on HbA1c (WMD 0.04%, 95% CI -0.08 to 0.16, I² = 45.7%, n = 3070), FPG (2.25 mg/dl, 95% CI -3.50 to 7.99, I² = 46%, n = 1176), BMI, fasting insulin or HOMA-IR. However, subgroup analysis showed significant, detrimental effect of atorvastatin on HbA1c, whereas simvastatin presented an ameliorative effect. Meta-regression presented that neither baseline age nor relative reduction in LDL-cholesterol concentrations accounted for residual heterogeneity. CONCLUSION: Statin therapy showed non-significant effect on glycaemic control in type 2 diabetes. Statin therapy need not change among them with moderate or high cardiovascular risk or existing cardiovascular disease.

[The effects of hyperosmotic stress on rabbit ocular surface and mucin 5AC expression].

OBJECTIVE: To investigate the effects of hyperosmotic stress on rabbit ocular surface and mucin 5AC (MUC5AC) expression. METHODS: Experimental study. Eighteen New Zealand white rabbits were randomly divided into three groups with equal number as hyperosmolar saline solution (HOSS, 500 mmol/L) group, normal saline (NS, 308 mmol/L) group and blank control group respectively. In HOSS and NS groups, the HOSS and NS eye drops were instilled on bilateral eyes six times every day for 14 days. On day 0, 7 and 14, Schirmer I test and tear break-up time (BUT) were measured and conjunctival impression cytology specimens were collected. On day 7 and 14, cornea and conjunctiva were harvested for Hematoxylin and Eosin (HE) staining, scanning and transmission electron microscopy observation and conjunctival TUNEL examination. On day 14, the conjunctiva were also harvested for immunology histological staining and western blot to evaluate the expression of MUC5AC. RESULTS: In HOSS group, the BUT on day 7 and 14 was (7.6 ± 2.5) and (7.0 ± 2.3) s respectively which was significantly shorter than the (10.3 ± 2.5) s on day 0(t = 5.800, 4.950; P < 0.01), and also significantly shorter than the BUT in NS and control groups (F = 8.030, P < 0.01). But the Schirmer I test value did not change obviously in and between all those three groups. The mean conjunctival goblet cell (GC) density in HOSS group on day 7 and 14 was (19.5 ± 16.6) and (32.3 ± 18.2) cells/mm(2) respectively which was also significantly lower than the (75.7 ± 43.4) cells/mm(2) on day 0 (t = 5.319, 2.970; P < 0.05). However the GC density did not change obviously in other two groups with time. After instillation of HOSS for 14 days, subepithelial inflammatory cell infiltration was showed on conjunctival tissue specimens and decreased epithelial layers and evident desquamation were found in the cornea specimens by the HE staining. Under the electron microscope, decreased microvilli and loosened intercellular junction in the superficial epithelium and increased autophagic vesicles in basal epithelium were observed in the cornea in HOSS group; and decreased microvilli and mucous granules were found in the conjunctiva in HOSS group. Obvious TUNEL positive staining was showed in the conjunctiva in the HOSS group. Also the MUC5AC immunology histological staining and western blot indicated decreased MUC5AC protein expression in HOSS group. CONCLUSION: Hyperosmotic stress destroyed the structure of ocular surface epithelium, induced the decrease of conjunctival goblet cell density and MUC5AC expression, and led to the decreased tear film stability.