Green synthesis,properties, and catalytic application of zeolite (P) in production of biofuels from bagasse

This study reports the technical and economic feasibilities of converting sugar cane residue (bagasse) into biofuel by using novel zeolite (P) catalyst. Using silica gel, aluminum powder, and sodium hydroxide as a precursor material, zeolite (P) has been successfully fabricated by template free hydrothermal synthesis. The as‐prepared catalyst is used for the conversion of sugarcane residue into valuable hydrocarbons by an autoclaving process. The effect of various parameters on catalytic and conventional (noncatalytic) pyrolysis was scrutinized and compared. It has been recognized that conventional pyrolysis (without catalyst) and catalytic pyrolysis (with Cat (I) and Cat (II)) produced 25.06%, 80.31%, and 55.26% of combustible liquid. The facial synthesis, high thermal stability, and economic and environmental feasibilities of the as‐synthesized zeolite (P) makes it a promising catalyst for biofuel production from biomass.     

High level of antimicrobial resistance in Campylobacter jejuni isolated from broiler chickens in Estonia in 2005 and 2006

The development of antimicrobial resistance in Campylobacter jejuni and Campylobacter coli is a matter of increasing concern. Because campylobacteriosis is transmitted to humans usually via food of animal origin, the presence of antimicrobial-resistant campylobacters in broiler chickens has important public health implications. The aim of our study was to analyze resistance patterns of C. jejuni isolated from fecal samples collected at a large Estonian chicken farm, from cecal contents collected at slaughterhouses, and from meat samples collected at the retail establishments in 2005 and 2006. A total of 131 C. jejuni isolates were collected over a 13-month period and tested by the broth microdilution VetMIC method (National Veterinary Institute, Uppsala, Sweden) to determine the MICs of various antimicrobials. Resistance to one or more antimicrobials was detected in 104 (79.4%) of the 131 isolates. High proportions of the isolates were resistant to enrofloxacin (73.3%) and nalidixic acid (75.6%). Multidrug resistance (resistance to three or more unrelated antimicrobials) was detected in 36 isolates (27.5%), all of which were resistant to enrofloxacin. Multidrug resistance was significantly associated with enrofloxacin resistance (P < 0.01), and the use of enrofloxacin may select for multiresistant strains.     

High occurrence of Campylobacter spp. in Latvian broiler chicken production

Campylobacteriosis in humans is caused by thermotolerant Campylobacter spp., most commonly by C. jejuni and C. coli. However, no official data for human campylobacteriosis in Latvia is available or cases are heavily under-reported. In accordance with Commission Decision 2007/516/EC the Campylobacter spp. baseline study was performed in 2008 in Latvia but there was no continuous monitoring for the Campylobacter at broiler chicken production level in 2009. The aim of the present study was to determine the occurrence of Campylobacter spp. in broiler chicken production at slaughterhouse and retail level in Latvia. Poultry samples originated from the two biggest Latvian broiler slaughterhouses. Altogether, 240 fresh broiler chicken neck skins, 2400 intact broiler chicken intestines and 240 fresh broiler chicken carcasses were collected during the year 2010. A total of 92.5% of the pooled intestine samples; 60.8% of the neck skin samples and 56.3% of carcasses were positive for Campylobacter spp. There was seasonal variation in proportions of Campylobacter positive samples with seasonal peak on summer months.     

Impact of carbon nanotube additives on carbide-derived carbon-based electroactive polymer actuators

The effects of single-walled carbon nanotubes (SWCNTs) on the properties of carbide-derived carbon (CDC)-based electroactive polymer (EAP) actuators were studied. SWCNTs were used as an additive to increase the mesoporosity and electrical conductivity of the electrodes, and also to support the CDC matrix. EAP actuators with various ratios of SWCNTs to CDC in the electrodes were fabricated and their electromechanical and electrochemical characteristics were examined. The addition of SWCNTs to CDC-based electrodes significantly increased the bending strain and stress (bending force) of the actuators. The actuator assembled with electrodes containing SWCNTs and CDC in the ratio 50/50 (wt.%/wt.%) showed the highest strain output among the samples at lower frequencies (<0.1 Hz). The increase in maximum strain was more than twice that of pure CDC-based EAPs (0.85% vs. 0.35% at an applied voltage of ±2 V). Also, the high frequency (5–50 Hz) response of the combined SWCNT/CDC-based actuators was considerably improved.     

Assessment of the ultraviolet radiation field in ocean waters from space-based measurements and full radiative-transfer calculations

Quantitative assessment of the UV effects on aquatic ecosystems requires an estimate of the in-water radiation field. Actual ocean UV reflectances are needed for improving the total ozone retrievals from the total ozone mapping spectrometer (TOMS) and the ozone monitoring instrument (OMI) flown on NASA's Aura satellite. The estimate of underwater UV radiation can be done on the basis of measurements from the TOMS/OMI and full models of radiative transfer (RT) in the atmosphere-ocean system. The Hydrolight code, modified for extension to the UV, is used for the generation of look-up tables for in-water irradiances. A look-up table for surface radiances generated with a full RT code is input for the Hydrolight simulations. A model of seawater inherent optical properties (IOPs) is an extension of the Case 1 water model to the UV. A new element of the IOP model is parameterization of particulate matter absorption based on recent in situ data. A chlorophyll product from ocean color sensors is input for the IOP model. Verification of the in-water computational scheme shows that the calculated diffuse attenuation coefficient Kd is in good agreement with the measured Kd.     

The rotating cylinder electrode

The transfer of mass onto a rotating cylindrical nickel electrode was investigated at relatively low rates. The simple electrochemical reaction of ferricyanide ion in an alkali medium was applied for this purpose. In the investigations particular attention was paid to the phenomenon of the penetration of eddies into the laminar sublayer. A modification and broadening of the basic Taylor expression, namely Taylor's linear theory, was proposed for the systems with a greater interelectrode distance. The experimental results can be better interpreted with a thus modified expression.Symbols A surface area - b constant - c _b,c _s bulk and surface concentrations - d _c diameter of rotating inner cylinder - D diffusion coefficient - zF Faradaic equivalence - h height - k _f friction factor - i ₁ limiting current density - I ₁ limiting current - dimensionless number - k _L mass transfer coefficient - N rotation per minute - r _i,r _o radii of inner and outer cylinders - = r _i peripheral velocity - x distance along the electrode - y distance normal to the electrode - _N, _Pr thickness of Nernst diffusion and Prandtl hydrodynamic boundary layers - _o thickness of laminar or viscous sublayer - coefficient of viscosity - density - kinematic viscosity - angular velocity - (Re) Reynolds number,d _c/ - (Sc) Schmidt number,/D - (Sh) Sherwood number,k _L d _c/D - (St) Stanton number,k _L/     

Structural, optical and hydrophilic properties of nanocrystalline TiO2 ultra-thin films prepared by pulsed dc reactive magnetron sputtering

TiO₂ ultra-thin (15 nm) films were deposited on silicon wafers (100) and glass slides by pulsed dc reactive magnetron sputtering in an ultra-high vacuum (UHV) system. The effects of substrate temperature, from room temperature to 400 °C, on structural, optical, and hydrophilic properties of the obtained films have been investigated. The structure of the films was characterized by grazing-incidence X-ray diffraction, high-resolution transmission electron microscopy, and atomic force microscopy. The optical properties were determined by UV-vis spectrophotometer and spectroscopic ellipsometry. The hydrophilic properties of the films, after exposed to ultraviolet illumination, were analyzed from contact angle measurements. The results suggested that the substrate temperature at 300 °C was critical in the crystalline phase transformation from amorphous to anatase in the TiO₂ films. The obtained films exhibited good qualities in the optical properties, in addition to excellent photo-induced hydrophilic activities.     

Silver nanoparticles deposited on anodic aluminum oxide template using magnetron sputtering for surface-enhanced Raman scattering substrate

Low-cost and highly sensitive surface-enhanced Raman scattering (SERS) substrates have been fabricated by a simple anodizing process and a magnetron sputtering deposition. The substrates, which consist of silver nanoparticles embedded on anodic aluminum oxide (AAO) templates, are investigated by a scanning electron microscope and a confocal Raman spectroscopy. The SERS activities are demonstrated by Raman scattering from adsorbed solutions of methylene blue and pyridine on the SERS substrate surface. The most optimized SERS substrate contains the silver nanoparticles, with a size distribution of 10-30 nm, deposited on the AAO template. From a calculation, the SERS enhancement factor is as high as 8.5 × 10⁷, which suggests strong potentials for direct applications in the chemical detection and analyses.