Recent years have witnessed remarkable progress in enhancing the supercontinuum (SC) generation in highly nonlinear photonic integrated waveguides. In this study, we conduct a comprehensive investigation into supercontinuum (SC) generation in high-index doped silica glass integrated waveguides. We explore a variety of femtosecond pumping wavelengths and input polarization states, demonstrating octave-spanning SC bandwidth from visible to mid-infrared wavelengths.

We present a comprehensive investigation of Raman scattering (RS) and supercontinuum (SC) generation in high-index doped silica glass integrated optical waveguides under diverse femtosecond pumping wavelengths and input polarization states. We first report the observation based on a confocal Raman microscope of new Raman peaks different from fused silica at 48 THz and 75 THz, respectively. We then demonstrate broadband supercontinuum generation from 700 nm to 2500 nm when pumping into the anomalous dispersion regime at 1200 nm, 1300 nm, and 1550 nm, respectively. Conversely, narrower SC spectra were generated when pumping in the normal dispersion regime at 1000 nm of self-phase modulation and optical wave breakup. A good agreement is found with numerical simulations of a nonlinear Schrodinger equation including the new Raman response. We also study the impact of the TE/TM polarization modes of the integrated waveguide on SC generation.

We report the observation of Brillouin backscattering in a 50-cm long spiral high-index doped silica chip waveguide and measured a Brillouin frequency shift of 16 GHz which is in very good agreement with theoretical predictions and numerical simulations based on the elastodynamics equation.

We review recent work using integrated and fibered platforms for advanced optical processing techniques. We show that machine learning in photonics systems can be leveraged to generate custom optical wave-packets relevant for targeted applications.

Brillouin scattering (BS), whereby light interacts coherently with hypersonic acoustic waves, is a powerful and flexible optical effect for processing light and microwave, making optical sensors, frequency combs, and lasers. While BS has been early exploited in optical fibers, it is only recently that it has been demonstrated in CMOS-compatible integrated waveguides based on chalcogenide (ChG), silicon (Si), or silicon nitride (SiN) in its stoichiometric composition (Si3N4) [1]–[4].

Many recent metasurfaces, consisting of one or two-dimensional artificial structures with subwavelength unit cells, have been designed to manipulate optical waves by achieving the 2π continuous phase gradients. In this paper, a method to transfer and control multi-beam reflections from a normal incident wave using a gradient-index metasurface is presented. By tuning properly the phase difference over the gradient-index metasurface, multi-beam anomalous reflections can be achieved, where the beam wavefronts are fully controlled by the refractive index distribution. The theoretical and simulated results show that some excellent multi-beam anomalous reflections are demonstrated by field distribution and radiation pattern of scattering field. Our method may help to offer a new design methodology for multi-beam steering in many interesting optics and microwave applications.

Axial-ratio bandwidth (ARBW) improvement of a circularly polarised printed monopole antenna using a lumped capacitor is presented. To demonstrate the effectiveness of this approach, a lumped capacitor is attached in the gap of an inverted-U-shaped patch antenna having a narrow 3 dB ARBW. Simulation shows that the ARBW improves from 4.1% (5.68-5.92 GHz) to 30.7% (4.33-5.9 GHz) with the use of a 0.5 pF capacitor. The measured results show a -10 dB reflection bandwidth of 60.5% (3.75-7 GHz), and a 3 dB ARBW of 33.3% (4.25-5.95 GHz). The advantage of the proposed design is that the 3 dB ARBW of an antenna can be easily tuned and extended with the use of only one lumped capacitor.

Rabies is an invariably fatal, but preventable zoonotic disease. Despite a national programme for its prevention and control, the number of rabies associated deaths in Vietnam has increased in recent years. A cross-sectional survey was undertaken in 2012 to assess and compare the knowledge, awareness and practices of 189 public health workers (PHW) and animal health workers (AHW) attending a joint training course for professionals from provinces in northern Vietnam with the highest number of deaths from rabies. Questionnaires facilitating self-evaluation were provided, and total knowledge scores were calculated (maximum 38 points) and categorized into: high' (>30 points), moderate' (21-30) and low' (<21). The response rate was 100%, and among the 189 participants, 56% were PHW compared to 44% who were AHW. Although most respondents knew rabies could be transmitted through the bite of an animal, most commonly a dog, and that rabies is a preventable disease, significant differences between groups were identified. Major areas included poor knowledge of common rabies reservoirs, wound management and guidance on post-exposure prophylaxis. Overall, the total mean knowledge scores for PHW was significantly higher (P=0.011) compared to those for AHW, but both scores fell within the moderate' knowledge range. However, proportionately more PHW than AHW achieved high' knowledge scores (P=0.0098). To our knowledge this is the first published study to simultaneously assess the knowledge and awareness of animal health and public health professionals attending joint training activities aimed at strengthening rabies prevention and control. To ensure effective prevention and control of rabies requires that AHW and PHW not only coordinate and collaborate, but have a common knowledge and understanding of rabies prevention and control measures. This study provides important baseline data in a relatively unexplored area of research that can focus future interventions and research.

Objectives: To assess and compare rabies related knowledge and awareness of public health workers at provincial and district levels in the seven provinces with the highest number of deaths from human rabies in northern Vietnam.Study design: A cross-sectional study.Method: A survey was administered to a convenience sample of public health workers attending four workshops on rabies disease, control and prevention between 16 October and 21 November, 2012. Total knowledge scores (maximum 38 points) were categorized into: 'high' (>30 points) 'moderate' (21-30) and 'low' (<21). The Chi-square test was used to evaluate the statistical significance of the differences in responses between the respondents.Results: Of the 105 public health workers attending the workshops: 57% were male; 76% worked at the district level compared with 24% who worked at provincial level; and 45% had worked in rabies control for <1 year compared with 11% who had worked in rabies control for >5 years. Overall knowledge was patchy and ranked as 'moderate'. Important gaps in knowledge were identified particularly in relation to indications for rabies vaccine and rabies immunoglobulin, and routes of exposure to rabies virus. One in ten respondents did not know that rabies virus could be transmitted by the bite of an infected animal. When examining the overall mean knowledge scores, marginally significant differences were identified. The average scores for district level health workers (DLHW) and provincial level health workers (PLHW) were 28 +/- 3 and 29 +/- 3 points respectively (p = 0.098), which fell within the study definition of 'moderate' knowledge. In contrast, when 'high' knowledge scores were compared, a significantly greater proportion of PLHW achieved >30 points compared to DLHW (44.0% vs 22.5%, p = 0.044).Conclusions: Important gaps in knowledge and awareness of public health workers were identified particularly in relation to routes of exposure to rabies virus and indications for rabies vaccine and rabies immunoglobulin. Overall, comparison of knowledge scores revealed significant differences between district and provincial public health workers. The results obtained suggest that in order for rabies control programmes to succeed public health workers at all levels need to have accurate and evidence-based knowledge. This may be facilitated by improving the quantity and quality of their training and education. (C) 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Acylation of oleic acid with ethanolamine was carried out using large mesoporous materials of UL-MFI-type. Mesostructured precursors having Si/Al ratios from 100 to 20, designated as Al-Meso-x were synthesized using SiCl 4 and AlCl 3 as silicon and aluminum sources, and Pluronic P123 in ethanol as surfactant. UL-ZSM-5 materials were obtained from surfactant containing the above precursors which were impregnated with an aqueous solution of tetrapropylammonium hydroxide followed by drying for several days. Chemo-and regioselectivity was controlled via a strong correlation of temperature and solvent effects.

The acid properties of UL-ZSM-5 materials were studied and found to be improved by a treatment in aqueous ammonia solutions. The catalytic properties in the aldol condensation of acetaldehyde with formaldehyde were examined after this treatment. The UL-ZSM-5 were found to be less sensitive to coke deactivation than ZSM-5 of comparable Si/Al ratio and more active than the mesostructured precursor.

The surface acidity of semicrystalline zeolitic mesoporous UL-ZSM-5 aluminosilicate materials of different degree of crystallinity (UL-zeolites were introduced recently in our laboratory [D. Trong On, S. Kaliaguine, Nanoporous Materials—Science and Engineering, Imperial College Press, 2005; D. Trong On, S. Kaliaguine, Angew. Chem. Int. Ed. 40 (2001) 3248; A. Ungureanu, D. Trong On, E. Dumitriu, S. Kaliaguine, Appl. Catal. A: Gen. 254 (2003) 203]) has been investigated by means of FTIR spectroscopy of adsorbed 2,6-ditertbutylpyridine (DTBPy) and the test reaction of transalkylation of toluene with 1,3,5-trimethylbenzene. FTIR experiments and catalytic tests allowed also characterizing the surface acidity of the starting amorphous mesostructured aluminosilicate precursor and the external acid sites of crystalline ZSM-5 zeolite. The results indicated that most of the Brönsted acidic OHs accessible to DTBPy molecules are terminal on the mesopore surfaces of both UL-ZSM-5 materials and mesostructured aluminosilicate and also on the external surface of ZSM-5. These sites, which are responsible for the OH stretching band near 3745 cm−1, are of medium strength. Their density correlated well with the external surface area. On the other hand, bridging SiOHAl sites generating OH stretching band at 3612 cm−1 and conferring the medium-strong Brönsted acidity of UL-ZSM-5 and ZSM-5 are located predominantly in the micropores of the zeolitic ZSM-5 phase and thus not accessible to bulky DTBPy. Just like the external surface of ZSM-5, the mesoporous surface of UL-ZSM-5 carries a small fraction of bridging Brönsted acid sites which are likely located in the pore mouth region of their ZSM-5 zeolitic phase. The catalytic activity of the distinct aluminosilicate materials under study as well as the selectivity towards the different reactions involved in the transalkylation process has been found to strongly depend on the nature, density, strength and accessibility of the characteristic Brönsted acid sites.

Fe-SBA-15 was successfully synthesized by hydrothermal treatment in one step . Different techniques such as XRD, BET, HRTEM, UV-vis have been used to characterize the Fe-SBA-15 samples. Obtained results have shown that the obtained Fe-SBA-15 samples have highly ordered hexagonal mesostructure with large pore size of about 64Å. Most Fe species in the Fe-SBA-15 were tetrahedrally coordinated. The sample exhibited high stability by calcination at high temperature to remove the template. The Fe-SBA-15 catalysts were tested in catalytic oxidation of phenol and photocatalytic oxidation of chlorophenol. The results indicated that Fe-SBA-15 exhibited the high catalytic activity in these reactions.