An Active Flow Control over the Ship Deck for Helicopter Shipboard Operations

This paper presents an active flow control of ship airwake over the deck to improve the safety of helicopter shipboard operations in various angles of wind over deck (WOD). Firstly, an integrated flight dynamics method coupled with ship airwake was developed to analyze the effect of ship airwake on the helicopter at various angles of WOD. Then, an active flow control strategy in various angles of WOD was investigated with the analysis of airwake distribution and the impact on helicopter trim flight. Finally, the effects of active blowing on airwake distribution, flight control inputs, control margins, and helicopter attitudes in trim were analyzed. The results indicate that the variation of the angles of WOD has a significant impact on flight controls and helicopter attitudes for helicopter hovering relative to ship motion. The nonuniformity of ship airwake can be effectively alleviated by applying active flow control. The variations of flight control inputs and helicopter attitude angles at trim states are reduced, which increases the control margins and contributes to enhancing the safety of helicopter shipboard operations

Effect of Boron Compound Addition in Flame Deposition of Functional Films

Superhydrophobic SiO2 films have been prepared by a flame deposition method. The influence of boron compound as additive on the morphology, structure and property has been studied with SEM and quantitative nanomechanical property mapping (QNM, Bruker). SEM photographs show that the size of nanoparticles in the deposited film has increased due to the addition of boron compound. The deposit rate also improves as the concentration of the boron compound increases. Boron compound has effectively promoted the precursor reaction in the gas phase. As is shown by QNM characterization, under all selected concentrations of boron additive, boron compound improves the fusion between the flame made nanoparticles and the substrate, achieving higher binding capacity. The superhydrophobic property of deposited films has been affected by the changed morphology and structure caused by boron additive. The proportion of nano-scale structure on the surface has decreased, leading to a constant contact angle but greatly decreased rolling angle. The mechanism has been preliminarily explored based on the special property of boron and flame reaction process. Surface growth and low temperature diffusion contribute to the enhancement of film binding force

Sonication-assisted dispersion of carbon nanotubes in aqueous solutions of the anionic surfactant SDBS: The role of sonication energy

Sonication is a powerful technique to promote the dispersion of carbon nanotubes (CNTs) and enhance their solubility; this is necessary for CNT applications, especially in the biochemical and biomedical fields. In this study, batch experiments were conducted to evaluate the role of sonication energy on the dispersion of CNTs in the presence of a widely used anionic surfactant, sodium dodecylbenzene sulfonate (SDBS). It was observed that the concentration of dispersed CNTs in the SDBS solution depended on the sonication energy, but not the sonication time or output power of the sonicator alone. The amount of dispersed CNTs was positively correlated with the concentrations of SDBS and CNTs, and the length of the CNTs. The promotion of oxygen-containing functional groups on the dispersed CNTs was observed at relatively low sonication energies. The optimal energy, i.e. the minimum energy supplied by sonication to achieve a saturated suspension of dispersed CNTs in the SDBS solution, was CNT diameter-dependent, because of the larger vdW forces between tubes of smaller diameter. An exponential decay curve was constructed for the optimal energy values as a function of the outer CNT diameter, to assist in determining the energy needed to disperse CNTs

Anti-fogging and anti-reflective silica nanofibrous film fabricated by seedless flame method

Here we report a multifunctional SiO2 nanofibrous film fabricated on plain glass by the seedless flame spray pyrolysis method. The SiO2 nanowires show different morphologies as growth time increase due to the alteration of gas precursor diffusion conditions. The growth route of nanowires has been divided into several stages due to the different dominant growth type. The densification and overlapping caused by radial and axial growth in competitive relation endow the as-made SiO2 films with increased surface area and sub-wavelength scale structure. Combining the hydrophilicity of flame-made SiO2 and the special fibrous structure, the nanofibrous SiO2 film exhibits considerable anti-fogging and anti-reflective properties. (C) 2013 Published by Elsevier B.V

Facile fabrication of nano-structured silica hybrid film with superhydrophobicity by one-step VAFS approach

Here we report a novel one-step vapor-fed aerosol flame synthesis (VAFS) method to attain silica hybrid film with superhydrophobicity on normal glass and other engineering material substrates using hexamethyldisiloxane (HMDSO) as precursor. The deposited nano-structured silica films represent excellent superhydrophobicity with contact angle larger than 150 degrees and sliding angle below 5 degrees, without any surface modification or other post treatments. SEM photographs proved that flame-made SiO2 nanoparticles formed dual-scale surface roughness on the substrates. It was confirmed by FTIR and XPS that the in situ formed organic fragments on the particle surface as species like (CH3)(x)SiO2-x/2 (x = 1, 2, 3) which progressively lowered the surface energy of fabricated films. Thus, these combined dual-scale roughness and lowered surface energy cooperatively produced superhydrophobic films. IR camera had been used to monitor the real-time flame temperature. It is found that the inert dilution gas inflow played a critical role in attaining superhydrophobicity due to its cooling and anti-oxidation effect. This method is facile and scalable for diverse substrates, without any requirement of complex equipments and multiple processing steps. It may contribute to the industrial fabrication of superhydrophobic films. (C) 2012 Elsevier B.V. All rights reserved

Rare Metal Mat. Eng.

Al-doped ZnO nano-particles were synthesized by liquid-feed flame spray pyrolysis, a single step, continuous, and scaleable process. The as-synthesized ZnO nano-particles were characterized by SEM and XRD. They exhibited small crystallite size ranging from 30 to 40 nm with spherical shape, and the crystal structure was wurtzite. The electrical conductivity of the ZnO nano-particles after reducing atmosphere heat treatment was investigated by varying Al doping concentration, and a minimum resistance was obtained at the doping concentration of 8 mol%.Al-doped ZnO nano-particles were synthesized by liquid-feed flame spray pyrolysis, a single step, continuous, and scaleable process. The as-synthesized ZnO nano-particles were characterized by SEM and XRD. They exhibited small crystallite size ranging from 30 to 40 nm with spherical shape, and the crystal structure was wurtzite. The electrical conductivity of the ZnO nano-particles after reducing atmosphere heat treatment was investigated by varying Al doping concentration, and a minimum resistance was obtained at the doping concentration of 8 mol%

Sipuleucel-T and Androgen Receptor-Directed Therapy for Castration-Resistant Prostate Cancer: A Meta-Analysis

New treatments, such as sipuleucel-T and androgen receptor-(AR-) directed therapies (enzalutamide (Enz) and abiraterone acetate (AA)), have emerged and been approved for the management of castration-resistant prostate cancer (CRPC). There are still debates over their efficacy and clinical benefits. This meta-analysis aimed to investigate the efficacy and safety of sipuleucel-T and ARdirected therapies in patients with CRPC. RevMan 5.1 was used for pooled analysis and analysis of publication bias. Seven studies were included in the meta-analysis, with three studies in sipuleucel-T (totally 737 patients, 488 patients in treatment group, and 249 patients in placebo group) and four in AR-directed therapies (totally 5,199 patients, 3,015 patients in treatment group, and 2,184 patients in placebo group). Treatment with sipuleucel-T significantly improved overall survival in patients with CRPC and was not associated with increased risk of adverse event of grade ≥3 ( > 0.05). However, treatment with sipuleucel-T did not improve time-to-progression and reduction of prostate-specific antigen (PSA) level ≥50% was not significantly different from that with placebo. AR-directed therapies significantly improved overall survival in patients with CRPC and improved time-to-progression and reduction of PSA level ≥50%. AR-directed therapies did not increase risk of adverse event of grade ≥3 ( > 0.05)

Sipuleucel-T and Androgen Receptor-Directed Therapy for Castration-Resistant Prostate Cancer: A Meta-Analysis

New treatments, such as sipuleucel-T and androgen receptor- (AR-) directed therapies (enzalutamide (Enz) and abiraterone acetate (AA)), have emerged and been approved for the management of castration-resistant prostate cancer (CRPC). There are still debates over their efficacy and clinical benefits. This meta-analysis aimed to investigate the efficacy and safety of sipuleucel-T and AR-directed therapies in patients with CRPC. RevMan 5.1 was used for pooled analysis and analysis of publication bias. Seven studies were included in the meta-analysis, with three studies in sipuleucel-T (totally 737 patients, 488 patients in treatment group, and 249 patients in placebo group) and four in AR-directed therapies (totally 5,199 patients, 3,015 patients in treatment group, and 2,184 patients in placebo group). Treatment with sipuleucel-T significantly improved overall survival in patients with CRPC and was not associated with increased risk of adverse event of grade ≥3 (p > 0.05). However, treatment with sipuleucel-T did not improve time-to-progression and reduction of prostate-specific antigen (PSA) level ≥50% was not significantly different from that with placebo. AR-directed therapies significantly improved overall survival in patients with CRPC and improved time-to-progression and reduction of PSA level ≥50%. AR-directed therapies did not increase risk of adverse event of grade ≥3 (p > 0.05)