Growth behavior of titanium dioxide thin films at different precursor temperatures

The hydrophilic TiO2 films were successfully deposited on slide glass substrates using titanium tetraisopropoxide as a single precursor without carriers or bubbling gases by a metal-organic chemical vapor deposition method. The TiO2 films were employed by scanning electron microscopy, Fourier transform infrared spectrometry, UV-Visible [UV-Vis] spectroscopy, X-ray diffraction, contact angle measurement, and atomic force microscopy. The temperature of the substrate was 500°C, and the temperatures of the precursor were kept at 75°C (sample A) and 60°C (sample B) during the TiO2 film growth. The TiO2 films were characterized by contact angle measurement and UV-Vis spectroscopy. Sample B has a very low contact angle of almost zero due to a superhydrophilic TiO2 surface, and transmittance is 76.85% at the range of 400 to 700 nm, so this condition is very optimal for hydrophilic TiO2 film deposition. However, when the temperature of the precursor is lower than 50°C or higher than 75°C, TiO2 could not be deposited on the substrate and a cloudy TiO2 film was formed due to the increase of surface roughness, respectively

Fast Prediction of Multiple Parameters Related to Iced Airfoil Based on POD and Kriging Methods

Ice accretion threatens aircraft safety. With the wide application of unmanned aerial vehicles (UAVs), the design of ice-tolerant UAVs has become a problem that must be solved. Forty conditions for the continuous/intermittent maximum icing conditions were sampled in Appendix C of Federal Aviation Regulations Part 25. Herein, numerical simulations of icing were performed on an NACA 0009 airfoil for 5, 15, and 30 min, and the ice mass and ice shapes were obtained at different times. Numerical simulations of the aerodynamic characteristics of the iced configuration at 5, 15, and 30 min were conducted, and the coefficients of lift, drag, and pitch moment were obtained. Surrogate models of the ice shape, mass of the ice accretion, lift coefficient, drag coefficient, and pitch moment coefficient at different moments were built based on proper orthogonal decomposition and kriging interpolation. The results demonstrate that the surrogate models accurately predicted the ice shape, ice mass, lift coefficient, drag coefficient, and pitch moment coefficient at different moments. Compared with the numerical simulation results, the maximum relative errors of the ice mass, lift coefficient, drag, and pitch moment predicted by the surrogate models were 7.8%, 3.4%, 3.9%, and 7.6%, respectively. This method can help in designing the ice-tolerant UAVs and envelope determination under icing conditions

Superconducting gap anisotropy of LuNi2B2C thin films from microwave surface impedance measurements

Surface impedance measurements of LuNi2B2C superconducting thin films as a function of temperature have been performed down to 1.5 K and at 20 GHz using a dielectric resonator technique. The magnetic penetration depth closely reproduces the standard B.C.S. result, but with a reduced value of the energy gap at low temperature. These data provide evidence for an anisotropic s-wave character of the order parameter symmetry in LuNi2B2C. From the evaluation of the real part of complex conductivity, we have observed constructive (type II) coherence effects in the electromagnetic absorption below Tc.Comment: 15 pages, 4 figure

Computational Model for Urban Growth Using Socioeconomic Latent Parameters

Land use land cover changes (LULCC) are generally modeled using multi-scale spatio-temporal variables. Recently, Markov Chain (MC) has been used to model LULCC. However, the model is derived from the proportion of LULCC observed over a given period and it does not account for temporal factors such as macro-economic, socio-economic, etc. In this paper, we present a richer model based on Hidden Markov Model (HMM), grounded in the common knowledge that economic, social and LULCC processes are tightly coupled. We propose a HMM where LULCC classes represent hidden states and temporal fac-tors represent emissions that are conditioned on the hidden states. To our knowledge, HMM has not been used in LULCC models in the past. We further demonstrate its integration with other spatio-temporal models such as Logistic Regression. The integrated model is applied on the LULCC data of Pune district in the state of Maharashtra (India) to predict and visualize urban LULCC over the past 14 years. We observe that the HMM integrated model has improved prediction accuracy as compared to the corresponding MC integrated modelComment: 12 page

Serum Amyloid A in Stable COPD Patients is Associated with the Frequent Exacerbator Phenotype

Background: We sought to determine whether circulating inflammatory biomarkers were associated with the frequent exacerbator phenotype in stable COPD patients ie, those with two or more exacerbations in the previous year. Methods: Eighty-eight stable, severe, COPD patients (4 females) were assessed for exacerbation frequency, pulmonary function, fraction of expired nitric oxide (FENO); inflammatory variables were measured in venous blood. Logistic regression assessed associations between the frequent exacerbator phenotype and systemic inflammation. Results: Compared with infrequent exacerbators, frequent exacerbators (n=10; 11.4%) had greater serum concentration (median (25th-75th quartile)) of serum amyloid A (SAA; 134 (84– 178) vs 71 (38– 116) ng/mL; P=0.024), surfactant protein D (SP-D; 15.6 (9.0– 19.3) vs 8.5 (3.6– 14.9) ng/mL; P=0.049) and interleukin-4 (IL-4; 0.12 (0.08– 1.44) vs 0.03 (0.01– 0.10) pg/mL; P=0.001). SAA, SP-D and IL-4 were not significantly correlated with FEV1%predicted or FVC %predicted. After adjusting for sex, age, BMI, FEV1/FVC and smoking pack-years, only SAA remained independently associated with the frequent exacerbator phenotype (OR 1.49[1.09– 2.04]; P=0.012). The odds of being a frequent exacerbator was 18-times greater in the highest SAA quartile (≥ 124.1 ng/mL) than the lowest SAA quartile (≤ 44.1 ng/mL) (OR 18.34[1.30– 258.81]; P=0.031), and there was a significant positive trend of increasing OR with increasing SAA quartile (P=0.008). For SAA, the area under the receiver operating characteristic curve was 0.721 for identification of frequent exacerbators; an SAA cut-off of 87.0 ng/mL yielded an 80% sensitivity and 61.5% specificity. Conclusion: In stable COPD patients, SAA was independently associated with the frequent exacerbator phenotype, suggesting that SAA may be a useful serum biomarker to inform progression or management in COPD

Limitations of perturbative techniques in the analysis of rhythms and oscillations

Perturbation theory is an important tool in the analysis of oscillators and their response to external stimuli. It is predicated on the assumption that the perturbations in question are “sufficiently weak”, an assumption that is not always valid when perturbative methods are applied. In this paper, we identify a number of concrete dynamical scenarios in which a standard perturbative technique, based on the infinitesimal phase response curve (PRC), is shown to give different predictions than the full model. Shear-induced chaos, i.e., chaotic behavior that results from the amplification of small perturbations by underlying shear, is missed entirely by the PRC. We show also that the presence of “sticky” phase–space structures tend to cause perturbative techniques to overestimate the frequencies and regularity of the oscillations. The phenomena we describe can all be observed in a simple 2D neuron model, which we choose for illustration as the PRC is widely used in mathematical neuroscience

QCD corrections to J/ψJ/\psi plus Z0Z^0-boson production at the LHC

The $J/\psi+Z^0$ associated production at the LHC is an important process in investigating the color-octet mechanism of non-relativistic QCD in describing the processes involving heavy quarkonium. We calculate the next-to-leading order (NLO) QCD corrections to the $J/\psi +Z^0$ associated production at the LHC within the factorization formalism of nonrelativistic QCD, and provide the theoretical predictions for the distribution of the $J/\psi$ transverse momentum. Our results show that the differential cross section at the leading-order is significantly enhanced by the NLO QCD corrections. We conclude that the LHC has the potential to verify the color-octet mechanism by measuring the $J/\psi+Z^0$ production events.Comment: 14 page revtex, 5 eps figures, to appear in JHEP. fig5 and the corresponding analysis are correcte