Simultaneous heat and water recovery from flue gas by membrane condensation: experimental investigation

A tubular ceramic membrane is investigated as the condenser for simultaneous heat and water recovery from flue gas. The effects of the operational parameters, such as fluid (gas and water) flow rates, temperatures of flue gas and coolant water, and flue gas humidity on the process performance in terms of mass and heat transfer across the membrane are studied. Particularly, the overall heat transfer coefficient is also evaluated. As the gas flow rate increases, water and heat transfer efficiencies and recoveries decline due to the reduced residence time. Increasing the water flow rate or lowing the coolant temperature can effectively improve mass and heat transfer efficiencies and recoveries. Increasing the temperature of the inlet gas can enhance water and heat fluxes and recoveries, but does not improve the overall heat transfer efficiency. The rise in flue gas humidity can dramatically improve water and heat transfer rates and the overall heat transfer coefficient, but has little effect on water and heat recoveries. These results offer a general guideline in optimising the operational parameters in low-grade heat recovery with membrane heat exchangers, and it may greatly advance the development of membrane condensation technology for practical low-grade heat recovery

Identification and pathogenicity of Aurifilum species (Cryphonectriaceae, Diaporthales) on Terminalia species in Southern China

The family of Cryphonectriaceae (Diaporthales) contains many important tree pathogens and the hosts are wide-ranging. Tree species of Terminalia were widely planted as ornamental trees alongside city roads and villages in southern China. Recently, stem canker and cracked bark were observed on 2–6 year old Terminalia neotaliala and T. mantaly in several nurseries in Zhanjiang City, Guangdong Province, China. Typical conidiomata of Cryphonectriaceae fungi were observed on the surface of the diseased tissue. In this study, we used DNA sequence data (ITS, BT2/BT1, TEF-1α, rpb2) and morphological characteristics to identify the strains from Terminalia trees. Our results showed that isolates obtained in this study represent two species of Aurifilum, one previously described species, A. terminali, and an unknown species, which we described as A. cerciana sp. nov. Pathogenicity tests demonstrated that both A. terminali and A. cerciana were able to infect T. neotaliala and two tested Eucalyptus clones, suggesting the potential for Aurifilum fungi to become new pathogens of Eucalyptus

Liver Receptor homolog-1 Regulates Apoptosis of Bovine Ovarian Granulosa Cells by Progestogen Receptor Signaling Pathway

The purpose of the present investigation was to assess the function of LRH-1 on GCs and the mechanisms involved. Here, LRH- was highly expressed in the bovine GCs of atretic follicles. Treatment with 50 μM of LRH-1 agonist (DLPC) significantly induced the expression of LRH-1 (p < 0.05). In particular, LRH-1 activation blocked the progestogen receptor signaling pathway via downregulating progesterone production and progestogen receptor levels (p < 0.05), but had no effect on 17 beta-estradiol synthesis. Meanwhile, LRH-1 activation promoted the apoptosis of GCs and increased the activity of caspase 3 (p < 0.05). Importantly, upregulating the progestogen receptor signaling pathway with progestogen could attenuate the LRH-1-induced proapoptotic effect. Moreover, treatment with progestogen decreased the activity of the proapoptotic gene caspase 3 and increased the expression of antiapoptotic gene Bcl2 in LRH-1 activated GCs (p < 0.05). Taken together, these results demonstrate that LRH-1 might be dependent on the progestogen receptor signaling pathway to modulate bovine follicular atresia

Pd-doped organosilica membrane with enhanced gas permeability and hydrothermal stability for gas separation

A Pd-doped organosilica membrane based on bis(triethoxysilyl)ethane is successfully developed by the polymeric sol–gel method. Its microstructure, chemical composition, and separation performance are compared with those of the undoped organosilica membrane. Gas adsorption analysis indicates that the Pd-doped organosilica membrane has larger micropores compared with the undoped organosilica membrane. The gas permeation results show that the Pd-doped organosilica membrane has much higher gas permeances than the undoped organosilica membrane due to the enlarged micropores after Pd-doping. The Pd-doped organosilica membrane also exhibits a significantly improved hydrothermal stability. The enhanced hydrothermal stability can be explained by the mechanism that Pd particles act as inhibitors and prevent the formation of mobile silica groups (e.g., Si–OH) under steam condition. Metal-doping (e.g., Pd-doping in this work) may offer a new approach to develop high performance membranes with enhanced gas permeances and hydrothermal stabilities in gas separation applications.12 page(s

Biogas upgrading by CO₂ removal with a highly selective natural amino acid salt in gas–liquid membrane contactor

For biogas upgrading, a natural amino acid salt, potassium l-argininate (PA) is studied in a membrane contactor to capture CO₂ from biogas. CO₂ removal performance in terms of the overall volumetric gas phase mass transfer coefficient, membrane selectivity towards CO₂ and the economic cost factor is systematically investigated. It is shown that PA is a highly CO₂ selective absorbent and has a better affinity towards CO₂ than monoethanolamine (MEA). The highest CH₄ content in the upgraded biogas can reach about 99.15 vol% by using PA, fully meeting the requirement of biogas upgrading. Furthermore, lower solvent concentration, lower liquid velocity and higher reaction temperature may be adopted when using PA in comparison to MEA. PA also has a better flexibility to the change of CO₂ partial pressure and biogas flow rate than MEA. Regarding the economic cost factor of membrane process, CO₂ loading of the lean PA solution can be optimized to 0.69–0.78 mol/mol as the suitable range. Moreover, CO₂ removal performance of l-arginine (ARG) is also explored. Due to the large amounts of bicarbonate other than carbamate formed in CO₂-rich ARG solution, ARG has a lower biogas upgrading capability than diethanolamine (DEA) but higher than triethanolamine (TEA).11 page(s

Enhancing wetting resistance of poly(vinylidene fluoride) membranes for vacuum membrane distillation

We model the magnetic ratchet effect in bilayer graphene in which a dc electric current is produced by an ac electric field of frequency $\omega$ in the presence of a steady in-plane magnetic field and inversion-symmetry breaking. In bilayer graphene, the ratchet effect is tunable by an external metallic gate which breaks inversion symmetry. For zero in-plane magnetic field, we show that trigonal warping and inversion-symmetry breaking are able to produce a large dc valley current, but not a non-zero total dc charge current. For the magnetic ratchet in a tilted magnetic field, the perpendicular field component induces cyclotron motion with frequency $\omega_c$ and we find that the dc current displays cyclotron resonance at $\omega_c = \omega$, although this peak in the current is actually smaller than its value at $\omega_c = 0$. Second harmonic generation, however, is greatly enhanced by resonances at $\omega_c = \omega$ and $\omega_c = 2\omega$ for which the current is generally much larger than at $\omega_c = 0$.Comment: 13 pages, 2 figures, added section about valley current

Bevacizumab Combined with Chemotherapy for Advanced Non-small Cell Lung Cancer: A meta-analysis

Background and objective Bevacizumab is a recombinant, humanised, monoclonal antibody against the vascular endothelial growth factor receptor (VEGFR), the aim of this meta-analysis is to evaluate the clinical efficacy and safety of bevacizumab combined with chemotherapy for non-small cell lung cancer (NSCLC). Methods The CBM, CNKI, VIP, WanFang, The Cochrane Library, PubMed, Ovid, EMBASE and SCI etc were retrieved by computer, the randomized controlled trials (randomized control trial, RCT) of bevacizumab combined with chemotherapy in the treatment of NSCLC were collected by us. The outcomes included overall survival (OS), progression-free survival (PFS), response rate (RR), toxicities and treatment related mortality. Relative risk (RR) and hazard ratios (HR) were used for the meta-analysis and were expressed with 95% confidence intervals (95%CI), and the software Stata 12.0 was used for meta-analyses. Results Six trials and 2,338 advanced NSCLC patients were included. Meta analysis indicated that compared with chemotherapy alone, the bevacizumab (7.5 mg/kg or 15 mg/kg) combination with chemotherapy could increase overall survival rate (RR=1.68, P<0.01, 95%CI: 1.31-2.15; RR= 1.79, P<0.01, 95%CI: 1.53-2.08), and could decrease the progression of the disease risk (HR=0.75, P<0.01, 95%CI: 0.61-0.89; HR=0.69, P<0.01, 95%CI: 0.62-0.77) and the risk of disease death (HR=0.94, P<0.01, 95%CI: 0.77-1.10; HR=0.87, P<0.01, 95%CI: 0.78-0.97). The high dose of bevacizumab (15 mg/kg) combination with chemotherapy could increase the treatment related mortality (RR=1.88, P=0.010, 95%CI: 1.16-3.05) and the rates of other toxic reaction. Conclusion Whether first-line or second-line treatment, the addition of bevacizumab to chemotherapy in patients with advanced NSCLC prolongs RR, OS and PFS

Once-through CO2 absorption for simultaneous biogas upgrading and fertilizer production

© 2017 Elsevier B.V. A new process is developed for biogas upgrading using the total ammonia nitrogen (TAN) in biogas slurry as a renewable absorbent. TAN in biogas slurry can be transferred into free ammonia by adding NaOH to increase the solution pH. Increasing the pH of biogas slurry to 10 causes that > 90% TAN transfers into free ammonia, leading to high TAN removal ratios. However, further increasing the pH of biogas slurry has limited effects. Vacuum membrane distillation (VMD) has higher kinetics constants and thus is a more effective way to recover and enrich ammonia from biogas slurry compared with thermal or air stripping. After VMD, the recovered aqueous ammonia solution with high TAN concentrations and the enhanced biogas slurry can be used as “once-through” CO2 absorbents. With alkaline addition, VMD does not increase the CO2 absorption capacity, but significantly minimizes the phytotoxicity of biogas slurry. When NaOH dosage is below 0.25 M, superior ammonia separation performance with high kinetics constants and low phytotoxicity can be achieved. The recovered aqueous ammonia solution also has excellent CO2 absorption performance for biogas upgrading and can help obtain high content of methane. This study provides an effective process for biogas upgrading with low costs and generation of valuable products, including high purity bio-methane, low phytotoxicity biogas slurry for agricultural application and high concentration NH4HCO3 as a fertilizer