Adsorptive removal of phenols by Fe(III)/Cr(III) hydroxide,an industrial solid waste

Phenolics have recently been of great concern because of the extreme toxicity and persistency in the environment. Laboratory investigations of the potential use of Fe(III)/Cr(III) hydroxide as an adsorbent for the removal of bisphenol A and 2-aminophenol from aqueous solution were conducted. The operating variables studied are agitation time, initial concentration, adsorbent dose, pH and temperature. Equilibrium data follow Langmuir, Freundlich and Dubinin–Radushkevich isotherms. The Langmuir adsorption capacity of untreated and pretreated adsorbent was found to be 3.47 and 3.67 mg g⁻¹, respectively, for bisphenol A; and 2.94 and 6.03 mg g⁻¹ for 2-aminophenol. Adsorption was analyzed using first order, second order and Elovich kinetic models and the data were found to follow second order and Elovich kinetic models for the adsorption of bisphenol A by untreated adsorbent and first order and Elovich kinetic models for the adsorption of 2-aminophenol by untreated adsorbent. Thermodynamic parameters such as ΔG ⁰, ΔH ⁰ and ΔS ⁰ for the adsorption were evaluated.     

A simple and facile method to synthesize Co3O4 nanoparticles from metal benzoate dihydrazinate complex as a precursor

This report describes the novel synthesis of cobalt oxide (Co₃O₄) nanoparticles from corresponding metal benzoate dihydrazinate complex as a precursor followed by thermal decomposition. Transmission electron microscopy (TEM) revealed nearly uniform nanoparticles with an average particle size of around 20 nm. X-ray diffraction (XRD) and selected-area electron diffraction (SAED) demonstrated that the nanoparticles were composed of pure cubic phase polycrystalline Co₃O₄. The nanoparticles were also confirmed by Raman spectroscopy. In principle, this simple and inexpensive synthetic procedure can be employed to prepare other transition metal oxide nanoparticles.     

Hydrogen dual-fuelling of compression ignition engines with emulsified biodiesel as pilot fuel

Dual-fuel compression ignition (CI) engine operation with hydrogen is a promising method of using hydrogen gas in CI engines via high-cetane pilot fuel ignition. However, hydrogen dual-fuel operation with neat pilot fuels typically produce: high NO_x emissions; and high combustion chamber pressure rise rates (leading to increased “Diesel knock” tendencies). While water-in-fuel emulsions have been used during normal CI engine operation to cool the charge and slow combustion rates in an effort to reduce NO_x emissions, these water-in-fuel emulsions have not been tested as pilot fuels during hydrogen dual-fuel combustion. In this work two water-in-biodiesel emulsions are tested as pilot fuels during hydrogen dual-fuel operation. Hydrogen dual-fuel operation generally produces at best comparable thermal efficiencies compared with normal CI engine operation, while the emulsified biodiesel pilot fuels generally increase thermal efficiencies when compared with the neat biodiesel pilot fuel during dual-fuel operation. There is also a clear reduction in NO_x emissions with emulsified pilot fuel use compared with the neat pilot fuel. The thermal efficiency increase is more apparent at higher engine speeds, while the NO_x reduction is more apparent at lower speeds. This is due to two conflicting effects (exclusive to emulsified pilot fuel) that occur in tandem. The first is the cooling effect of water vapourisation on the charge, while the second is the microexplosion phenomenon which enhances fuel-air mixing. The NO_x emission reduction is due to the emulsified pilot fuel lowering pressure rise rates compared with the neat pilot fuel, while the efficiency increase is due to a more homogeneous charge resulting from the violent microexplosion of the emulsified pilot fuel. Smoke, CO, HC and CO₂ emissions remain comparable to neat pilot fuel tests. Overall, emulsified pilot fuels can reduce NO_x emissions and increase thermal efficiencies, however not at the same instance and under different operating conditions. The general trends of reduced power output, reduced CO₂ and increased water vapour emission during hydrogen dual-fuel operation (with neat pilot fuels) are also maintained.     

Diesel and rapeseed methyl ester (RME) pilot fuels for hydrogen and natural gas dual-fuel combustion in compression-ignition engines

This paper presents experimental results of rapeseed methyl ester (RME) and diesel fuel used separately as pilot fuels for dual-fuel compression-ignition (CI) engine operation with hydrogen gas and natural gas (the two gaseous fuels are tested separately). During hydrogen dual-fuel operation with both pilot fuels, thermal efficiencies are generally maintained. Hydrogen dual-fuel CI engine operation with both pilot fuels increases NO_x emissions, while smoke, unburnt HC and CO levels remain relatively unchanged compared with normal CI engine operation. During hydrogen dual-fuel operation with both pilot fuels, high flame propagation speeds in addition to slightly increased ignition delay result in higher pressure-rise rates, increased emissions of NO_x and peak pressure values compared with normal CI engine operation. During natural gas dual-fuel operation with both pilot fuels, comparatively higher unburnt HC and CO emissions are recorded compared with normal CI engine operation at low and intermediate engine loads which are due to lower combustion efficiencies and correspond to lower thermal efficiencies. This could be due to the pilot fuel failing to ignite the natural gas-air charge on a significant scale. During dual-fuel operation with both gaseous fuels, an increased overall hydrogen-carbon ratio lowers CO₂ emissions compared with normal engine operation. Power output (in terms of brake mean effective pressure, BMEP) as well as maximum engine speed achieved are also limited. This results from a reduced gaseous fuel induction capability in the intake manifold, in addition to engine stability issues (i.e. abnormal combustion). During all engine operating modes, diesel pilot fuel and RME pilot fuel performed closely in terms of exhaust emissions. Overall, CI engines can operate in the dual-fuel mode reasonably successfully with minimal modifications. However, increased NO_x emissions (with hydrogen use) and incomplete combustion at low and intermediate loads (with natural gas use) are concerns; while port gaseous fuel induction limits power output at high speeds.     

A novel in vitro bladder pelvic nerve afferent model in the rat

OBJECTIVE: To develop an in vitro model to allow electrophysiological recordings from pelvic nerve afferents of the urinary bladder in the rat and to ascertain the stability and reproducibility of the model with time. MATERIALS AND METHODS: Six male Wistar rats (body weight approximately 100 g) were used in the study. The bladder (complete with accessory organs of prostate and seminal vesicles), urethra and penis, together with the attached pelvic nerve and L6/S1 nerve trunk, were removed intact and placed in a specially designed recording chamber containing oxygenated Krebs solution maintained at 30 degrees C. The bladder was catheterized urethrally and attached to a continuous-infusion pump and a pressure transducer. The L6/S1 nerve trunk was placed across a silicone-gel wall into a separate chamber containing liquid paraffin, in which multiunit recordings from pelvic nerve afferents originating from the bladder were made. The afferent nerve activities in response to repeated bladder distension with saline, at 0.04 mL/min for 8 min over 3 h, were compared using the paired t-test to assess the reproducibility of the model. Conduction velocity studies were also carried out to ascertain the proportion of C- and A delta-fibres in the multiunit recordings. RESULTS: Repeated bladder distension with saline over 3 h produced consistent and reproducible afferent nerve responses, signifying that the afferent nerves recorded in this study neither sensitize nor desensitize over time. This is an essential prerequisite when using this model to study the effects of pharmacological manipulation of the bladder on its afferent nerve response. Conduction velocity studies showed that approximately 30% of the afferent fibres recorded from were C-fibres with the remaining being A delta-fibres. CONCLUSIONS: An in vitro bladder pelvic nerve afferent model for the rat was developed successfully; it is stable and produces reproducible results with repeated bladder distension over at least 3 h.     

Retraction Note to: Online measurement of water quality and reporting system using prominent rule controller based on aqua care-IOT

Design Automation for Embedded Systems -     

Anionic dye adsorption characteristics of surfactant‐modified coir pith,a ‘waste’ lignocellulosic polymer

The surface of coir pith, an agricultural solid waste, was modified using a cationic surfactant hexadecyltrimethylammonium bromide. Adsorption of anionic dyes on surfactant‐modified coir pith was investigated in a series of batch adsorption experiments. Two anionic dyes, acid brilliant blue (acid dye) and procion orange (reactive dye), were used in the adsorption studies. The effect of process variables such as contact time, concentration of the dyes, adsorbent dose, temperature, and pH were studied in order to understand the kinetic and thermodynamic parameters of the process. The kinetics of adsorption obeyed the second‐order rate equation. The equilibrium adsorption data were fitted into the Langmuir and Freundlich isotherms. It was found that modified coir pith yielded adsorption capacities of 159 and 89 mg/g for acid brilliant blue and procion orange, respectively. Mechanisms involving ion exchange and chemisorption might be responsible for the uptake of dyes. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1538–1546, 2006     

Applicability of ToF-SIMS for monitoring compositional changes in bone in a long-term animal model

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a well-established technique in material sciences but has not yet been widely explored for implementation in life sciences. Here, we demonstrate the applicability and advantages of ToF-SIMS analysis for the study of minerals and biomolecules in osseous tissue. The locally resolved analysis of fragment ions deriving from the sample surface enables imaging and differentiation of bone tissue and facilitates histology on non-stained cross sections. In a rat model, bilateral ovariectomy combined with either a multi-deficiency diet or steroid treatment was carried out to create osteoporotic conditions. We focused our study on the Ca content of the mineralized tissue and monitored its decline. Calcium mass images of cross sections show the progressive degenerative changes in the bone. We observed a decreased Ca concentration in the edge region of the trabeculae and a decline in the Ca/P ratio. Additionally, we focused on the non-mineralized matrix and identified fragment ions that are characteristic for the collagen matrix. We observed trabeculae with wide ranges of non-mineralized collagen for the diet group owing to an impaired mineralization process. Here, the advantage of coeval monitoring of collagen and minerals indicated an osteomalacic model rather than an osteoporotic one.     

Removal of phosphate by adsorption onto oyster shell powder—kinetic studies

Kinetic studies on the removal of phosphate by adsorption onto oyster shell powder have been investigated at 24 °C. The results showed that the equilibrium occurred in 10 min and the equilibrium data followed the Freundlich isotherm. Freundlich constants were found to be k_f, 1.4 × 10^?2, and n, 0.71. The phosphate removal was not influenced by pH over the range 5.0–10.5. Continuous agitation studies at 24 °C and 530 rpm reached equilibrium after 7.7 days, when 24 g dm^?3 of oyster shell powder reduced the phosphate concentration from 50 to 7.0 mg dm^?3. The Lagergren rate constant for the slow adsorption process was observed to be 3.81 × 10^?4 dm³ min^?1. Comparison with calcium carbonate, GR grade, showed that oyster shell powder and CaCO₃ behave more or less in the same way. Copyright © 2004 Society of Chemical Industry     

The TORGO database of acoustic and articulatory speech from speakers with dysarthria

This paper describes the acquisition of a new database of dysarthric speech in terms of aligned acoustics and articulatory data. This database currently includes data from seven individuals with speech impediments caused by cerebral palsy or amyotrophic lateral sclerosis and age- and gender-matched control subjects. Each of the individuals with speech impediments are given standardized assessments of speech-motor function by a speech-language pathologist. Acoustic data is obtained by one head-mounted and one directional microphone. Articulatory data is obtained by electromagnetic articulography, which allows the measurement of the tongue and other articulators during speech, and by 3D reconstruction from binocular video sequences. The stimuli are obtained from a variety of sources including the TIMIT database, lists of identified phonetic contrasts, and assessments of speech intelligibility. This paper also includes some analysis as to how dysarthric speech differs from non-dysarthric speech according to features such as length of phonemes, and pronunciation errors.