bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxidation of biologically produced elemental sulfur under neutrophilic conditions
Authors: Fortuny Marc , Guisasola Albert , Casas Carles , Gamisans Xavier , Lafuente Javier , Gabriel David 
Published: January 2010

AbstractBACKGROUND: Previous research on a biotrickling filter for the removal of high loads of H2S showed that accumulation of elemental sulfur (S0) when dealing with high H2S concentrations could lead to reactor clogging. Since S0 can also serve as substrate for sulfur‐oxidising bacteria, this study investigates the biological oxidation of S0 as a remediation strategy.RESULTS: Results indicated that biological oxidation of S0 inside a clogged biotrickling filter occurred at a comparable rate to those reported for stirred tank reactors. When biologically produced dried and powdered S0 was manually added as a substrate in stirred tank reactor experiments, significantly lower S0 oxidation rates were found compared to those for biological S0 freshly produced in situ. It was speculated that either the powdered S0 particle size or the surface properties hindered S0 bioavailability even in a well‐stirred environment. Respirometric experiments with the same powdered S0 and acetone‐dissolved S0 confirmed that biological oxidation of S0 was basically limited by the solid S0 bioavailability.CONCLUSIONS: Therefore, results showed that S0 oxidation basically depends on S0 bioavailability and that Sulfate volumetric production rates as high as 3.48 mmol SO42− h−1 L−1 can be achieved inside a clogged biotrickling filter probably due to the high biomass retention capacity. Overall, the results indicate that biological oxidation of S0 can be considered a suitable strategy for unclogging bioreactors clogged with S0. Copyright © 2010 Society of Chemical Industry
Evaluation of innovative packing materials for the biodegradation of H2S: a comparative study
Authors: Dumont Eric , Andrès Yves 
Published: January 2010

AbstractThe biofiltration of gas polluted with H2S was carried out using innovative configurations of packing materials (i.e. a new synthetic material called UP20, sapwood, peat, pozzolan and pine bark). A comparison of seven different configurations (media alone or in combination) was made based on biofilter performances and pressure drop measurements. Biofilters were operated continuously for at least 95 days at a constant flow rate (0.5 N m3 h−1 corresponding to a superficial velocity of 65 m h−1 and an empty bed residence time of 57 s). Elimination capacities and removal efficiencies were calculated according to loading rates varying from 0 to 25.5 g m−3 h−1 (inlet concentration up to 400 mg m−3). Biofilter performances were modelled and biokinetic constants were calculated using the Ottengraf model and a modified Michaelis–Menten model. In terms of elimination capacity, packing materials can be ordered from the most efficient to the least efficient: peat–UP20 in a mixture > peat–UP20 in two layers > peat > pozzolan–UP20 in two layers > pine bark > sapwood–UP20 in two layers > sapwood. A maximal removal rate, Vm, of 55 g m−3 h−1 was calculated for biofilters filled with peat–UP20 (in a mixture or in two layers) and peat (in comparison, Vm = 8.3 g m−3 h−1 for a biofilter filled with sapwood). Peat is the best material to treat high H2S concentrations and the addition of UP20 can significantly increase the removal efficiency. The pozzolan–UP20 combination represents an interesting packing material to treat pollutant loading rates up to 5 g m−3 h−1 with low pressure drops. For low H2S concentrations, sapwood can be considered as a good support for H2S degradation with pollutant loading rates up to 4 g m−3 h−1. Copyright © 2010 Society of Chemical Industry
Interaction of compounds on biodegradation of ketone mixtures in a biofilter
Authors: Chan Wu‐Chung , Lai Tzu‐Yu 
Published: January 2010

AbstractBACKGROUND: Acetone and methyl ethyl ketone (MEK) are commonly mixed together in the effluent streams from the manufacturing of semiconductors and optics–electronics. The metabolic activity on the biodegradation of two or more pollutants may involve induction, inhibition or co‐metabolism, depending on the substrates and microbial species present. The compound interaction on the biochemical kinetic behaviours of an acetone and MEK mixture in a composite bead biofilter was investigated.RESULTS: The microbial growth rate and biochemical reaction rate of the two biodegraded compounds was inhibited and the inhibitive effect resulting from increasing the compound inlet concentration predominated at a higher compound inlet concentration for the single compound system. The microbial metabolic activity of biodegraded acetone in the microbial growth process and biochemical reaction process was inhibited as MEK was introduced and the inhibitive effect resulting from interaction of the compounds was more pronounced at higher MEK inlet concentrations and lower acetone inlet concentrations for the two compounds mixing system. The maximum elimination capacity of acetone and MEK for the two compounds mixing system was smaller and greater than those for the single compound system, respectively.CONCLUSION: The biodegradation rate of acetone in a biofilter would be inhibited as MEK was introduced. Copyright © 2010 Society of Chemical Industry
Effect of silicone oil fraction and stirring rate on methane degradation in a stirred tank reactor
Authors: Rocha‐Rios José , Muñoz Raúl , Revah Sergio 
Published: January 2010

AbstractBACKGROUND: Methane is an important greenhouse gas and its biological oxidation constitutes a cost‐effective alternative for low concentration emissions. Nevertheless, due to its low aqueous solubility (similar to oxygen), gas mass transfer is often the limiting step. Two‐phase partition bioreactors (TPPBs), have been proposed to increase the biodegradation of poorly soluble compounds. In this work, the effect of stirring rate and silicone oil fraction on abiotic volumetric oxygen transfer coefficient kLa and methane elimination capacity (EC) by a methanotrophic consortium in a stirred tank was studied.RESULTS: In abiotic conditions, the kLa increased when increasing both factors. Nevertheless, a negative effect on kLa was observed with silicone oil at the highest stirring rate (800 rpm). During methane biodegradation experiments, EC also improved when increasing both factors, but contrary to abiotic kLa, it was not affected at the highest stirring rate. While stirring rate was the dominant variable determining methane biodegradation, the effect of oil fraction was only significant above 200 rpm. A maximum EC improvement of 700% was observed when increasing stirring rate from 200 to 800 rpm with 10% of silicone oil.CONCLUSIONS: Increasing both stirring rate and oil fraction enhanced EC. The results were different from those observed with kLa suggesting that kLa is not sufficient to describe properly the mass transfer in TPPB because other factors (interfacial contact between the phases and physicochemical properties of organic phase) should be considered. Copyright © 2010 Society of Chemical Industry
Modeling of a hollow fiber membrane biofilm reactor for nitric oxide removal: model development and experimental validation
Authors: Kumar Amit , Ergas Sarina J. , Yuan Xin , Fitch Mark , Min Kyung‐Nan , Dewulf Jo , Van Langenhove Herman 
Published: January 2010

AbstractBACKGROUND: A diffusion and reaction model was developed for a hollow fiber membrane biofilm reactor (MBfR) to control nitric oxide (NO) emissions. In the MBfR, waste gases containing biodegradable compounds pass through the lumen of microporous hydrophobic hollow fiber membranes. Soluble, biodegradable compounds diffuse through the membrane pores and partition into a biofilm attached to the membranes where they are biodegraded. The membranes serve as a support for the microbial population and provide a large surface area for mass transfer. A dynamic model was developed for the MBfR which assumed biodegradation via Monod kinetics and constant biofilm thickness and density. The model was validated using experimental data from a study of NO removal (100 ppm) from a combustion gas mixture in a bench‐scale MBfR with an acclimatized nitrifying population.RESULTS: NO gas was treated in a bench‐scale MBfR at varying liquid recirculation velocities of 0.8 to 2.0 cm s−1. The gas residence time (τ), calculated as the membrane lumen volume divided by the gas flow rate, was 1.9 s. NO removal efficiency for synthetic combustion gas ranged between 68% and 73% at room temperature (20 °C).CONCLUSION: The MBfR shows promise for treatment of waste gases from combustion processes. The model predicted an optimal liquid recirculation velocity of 1.5 cm s−1 for NO removal, which is in good agreement with experimental data. Sensitivity experiments with the numeric model indicated that removal was a strong function of the biofilm density and the Monod maximum specific growth rate (µmax). Copyright © 2010 Society of Chemical Industry
Effect of drying and calcination on the toluene combustion activity of a monolithic CuMnAg/γAl2O3/cordierite catalyst
Authors: Wu Dongfang , Jiang Wei , Zhou Jiancheng 
Published: January 2010

AbstractBACKGROUND: This paper presents a mathematical modeling and factorial analysis of the toluene combustion activity of a cordierite monolith supported copper–manganese–silver mixed‐oxide catalyst in the drying and calcination processes, using response surface methodology. A central composite rotatable design is performed to collectively study the effect of drying temperature, calcination temperature and calcination time. Experimental results are provided to confirm the validity of the models developed.RESULTS: The calcination temperature is the most significant process factor affecting the catalytic combustion activity. It is also shown that the combustion activity increases in most cases with decreasing calcination time and that a moderate calcination or drying temperature is required to increase the combustion activity. The optimal factor levels are drying temperature 160 °C, calcination temperature 500 °C, and calcination time 3 h.CONCLUSIONS: There is significant scope to improve the combustion activity of the monolithic catalyst through the optimization of the drying and calcination process factors. Response surface methodology is an effective technique for mathematical modeling and factorial analysis of the catalytic activity of monolithic catalysts. Copyright © 2010 Society of Chemical Industry
Labelling of the guanylate cyclase activator cinaciguat (BAY 58‐2667) with carbon‐14, tritium and stable isotopes
Authors: Seidel D. , Pleiß U. 
Published: January 2010

AbstractFor studies of pharmacokinetics and drug metabolism of the new soluble guanylate cyclase activator cinaciguat (BAY 58‐2667) the 14C‐labelled compound was synthesized. The tritiated compound was required to elucidate the mode of action and the stable labelled compound was required for bio‐analytical studies by quantitative mass spectrometry as well. Two radiosyntheses are described with different formation of the labelled intermediate 1‐(chloro[14C]methyl)‐4‐(2‐phenylethyl)benzene. The first one started with 14C‐carboxylation of 1‐bromo‐4‐(2‐phenylethyl)benzene yielding the desired product in 5 steps. In the second synthesis intermediate 1‐(chloro[14C]methyl)‐4‐(2‐phenylethyl)benzene was formed by chloromethylation of bibenzyl with [14C]paraformaldehyde/hydrochloric acid subsequently resulting in the final product in three steps. Tritium labelling was performed by tritium exchange of the diester intermediate using an organo‐iridium catalyst and subsequent saponification. The stable labelled compound was synthesized via a convergent synthesis starting with 13C,15N‐cyanation of 1‐(chloromethyl)‐2‐{[4‐(2‐phenylethyl)benzyl]oxy}benzene and 13C‐cyanation of methyl 4‐bromobenzoate, respectively. The labelled product was obtained after 7 chemical steps. Copyright © 2010 John Wiley & Sons, Ltd.
Nocturnal Cool Island in the Sahelian city of Ouagadougou, Burkina Faso
Authors: Lindén Jenny 
Published: January 2010

AbstractRelatively little is known about the urban climate processes of the fastest growing cities in the world today. Described in this paper are urban–rural and intra‐urban variations in air temperature and humidity in one of these cities; Ouagadougou, Burkina Faso. Measurements were collected from car traverses and fixed site measurements during two field studies. The aim of the study was to determine the influence of land use on the urban climate in this hot‐dry region, with a focus on the role of vegetation and of a large centrally located reservoir.Analyses of results show that vegetation is the most important factor in the nocturnal urban climate in Ouagadougou, while effects of built up and paved areas are limited. Average urban–rural temperature differences demonstrate that while the evening urban heat island (UHI) reached only 1.9 °C, the cool island in a densely vegetated area was 5.0 °C cooler than the dry rural reference. Temperature differences of the same magnitude persisted throughout the night between vegetated and non‐vegetated areas, regardless of urban or rural setting. Cooling from the open water of the reservoir was the most important parameter during daytime, while during evenings and nights, direct effects of the open water of the reservoir are very limited, and the availability of water, allowing enhanced vegetation cover, is of much greater importance compared to the water itself.The results presented here show that the urban land cover, together with climatic region, can create significant differences in the physical properties driving the urban climate in a dry‐tropical city compared to those commonly found in temperate cities. Copyright © 2010 Royal Meteorological Society
In vitro inhibition of aggrecanase activity by tetracyclines and proteoglycan loss from osteoarthritic human articular cartilage
Authors: Steinmeyer Jürgen , Kordelle Jens , Stürz Henning 
Published: January 2010

AbstractTetracyclines were reported to slow down the progression of cartilage damage both in an animal model of osteoarthritis (OA) and in humans. In search for the underlying mechanisms we examined whether tetracyclines possess an inhibitory potential on the activity of aggrecanases and inflammatory mediators and can thus prevent proteoglycan (PG) loss from human articular cartilage. In vitro activity of aggrecanase‐1 and ‐2 was recorded in the presence of 1–100 µM tetracycline, minocycline, or doxycyline. Human knee articular cartilage explants were sorted according to the degree of OA and treated for 10 days with tetracycline derivatives in the presence of interleukin‐1 (IL‐1β). Synthesis and loss of PGs, nitric oxide (NO), and prostaglandin E2 (PGE2), as well as the viability were determined. Tetracyclines derivatives dose‐dependently inhibited the activities of both aggrecanases in vitro, whereas no inhibitory effect of tetracyclines on any proteoglycanolytic activities within IL‐1β‐treated human cartilage explants were found. Tetracyclines can significantly modulate NO and PGE2 levels, but have no effect on PG synthesis and loss within the same human cartilage explant cultures. Altogether, our data show that tetracyclines have no inhibitory potential on any proteoglycanolytic activities within mild or moderately affected human OA cartilage at therapeutic achievable plasma levels. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:828–833, 2010
Understanding geomorphic responses to environmental change: a 19 000‐year case study from semi‐arid central Texas, USA
Authors: Boulter Claire , Bateman Mark D. , Frederick Charles D. 
Published: January 2010

AbstractUnderstanding the impact of past climatic changes on landscape stability is crucial in order to predict and mitigate the effects of future changes. However, in arid and semi‐arid environments, reconstructions are often hampered by a poor understanding of the relationship between sediment deposition and climate. We present here data from central Texas, a region that is sensitive to environmental change but has received relatively little attention. The study integrates a chronology of 29 optically stimulated luminescence (OSL) ages from six sedimentary sites in a range of depositional contexts with a 19 000 a climate record derived from pollen extracted from the adjacent Boriack Bog. By comparing the two records, we aimed to assess the relationship between climate change and geomorphic activity. Data show that extensive aeolian and colluvial deposition occurred during the mid to late Holocene, with sedimentation generally increasing during more arid phases. However, a number of depositional events on slopes were associated with moister episodes, and sediment was also deposited in a summit setting immediately after phases of increased precipitation. Linkages between climate change and geomorphic response were therefore complex, being controlled by both sediment supply and transport energy. The climatic fluctuations identified in the Boriack Bog record highlight the sensitivity of central Texas to environmental change, while disparities in conditions recorded between it and other palaeoenvironmental sites in the southern USA emphasise the need for further work in order to enhance understanding of landscape sedimentary response to climate. Copyright © 2010 John Wiley & Sons, Ltd.
1‐Methylcyclopropene affects the antioxidant system of apricots (Prunus armeniaca L. cv. Búlida) during storage at low temperature
Authors: Egea Isabel , Flores Francisco B , Martínez‐Madrid Maria C , Romojaro Felix , Sánchez‐Bel Paloma 
Published: January 2010

AbstractBACKGROUND: Apricots (Prunus armeniaca cv. Búlida) were treated with 1 mL L−1 1‐methylcyclopropene (1‐MCP) immediately after harvest and stored in air at 2 °C for 21 days. Antioxidant levels (ascorbic acid and carotenoids), enzymatic antioxidant activities (superoxide dismutase (SOD) and unspecific peroxidase (POX)) and total antioxidant capacity (trolox equivalent antioxidant capacity (TEAC)) were determined. The level of oxidative stress was also established by measuring ion leakage during storage. The changes in the antioxidant potential of apricots were related to the capacity of 1‐MCP to increase their commercial life.RESULTS: 1‐MCP‐treated fruits exhibited higher SOD activity, whereas POX activity was significantly higher only after 21 days at 2 °C. Treated fruits also exhibited better retention of ascorbate and carotenoids and higher TEAC during storage. In accordance with these observations, lower ion leakage values were detected in 1‐MCP‐treated apricots.CONCLUSION: Taken together, these results suggest that 1‐MCP conferred a greater resistance to oxidative stress. This, along with the reduction in ethylene production, could contribute to the increase in commercial life and nutritional value observed in 1‐MCP‐treated apricots. Copyright © 2010 Society of Chemical Industry
The effect of gaseous ozone treatment on egg components
Authors: Fuhrmann Herbert , Rupp Nadine , Büchner Andrea , Braun Peggy 
Published: January 2010

AbstractBACKGROUND: Because of the salmonella problem in poultry, disinfection technologies are necessary. Ozone is a strong oxidant used for the disinfection of surfaces, drinking water and foods. However, since ozone not only destroys bacteria but may also damage eggs, it is necessary to clarify the effects of ozone treatment on hatching egg components. In this study, doses of gaseous ozone ranging from 10 to 50 mL L−1 were tested. The vitamin A and E contents and fatty acid composition of the egg yolk were determined. To detect possible damage to the DNA of the germ disc, single‐cell gel electrophoresis was used. Moreover, free SH groups were measured in the egg white. The soluble cuticula proteins were analysed by polyacrylamide gel electrophoresis.RESULTS: The yolk was not significantly affected by ozone treatment. However, the DNA of the germ disc was attacked and a significant decrease in free SH groups in the egg white was recorded at 50 mL L−1 ozone. Even at low ozone doses the soluble cuticula proteins were completely destroyed.CONCLUSION: Significant alterations of egg components were caused by 50 mL L−1 ozone. At lower ozone doses the oxidative processes occurred mainly at the egg surface and are therefore probably harmless to the developing embryo. Copyright © 2010 Society of Chemical Industry
Cultural adaptation and translation of measures: An integrated method
Authors: Sidani Souraya , Guruge Sepali , Miranda Joyal , Ford‐Gilboe Marilyn , Varcoe Colleen 
Published: January 2010

AbstractDifferences in the conceptualization and operationalization of health‐related concepts may exist across cultures. Such differences underscore the importance of examining conceptual equivalence when adapting and translating instruments. In this article, we describe an integrated method for exploring conceptual equivalence within the process of adapting and translating measures. The integrated method involves five phases including selection of instruments for cultural adaptation and translation; assessment of conceptual equivalence, leading to the generation of a set of items deemed to be culturally and linguistically appropriate to assess the concept of interest in the target community; forward translation; back translation (optional); and pre‐testing of the set of items. Strengths and limitations of the proposed integrated method are discussed. © 2010 Wiley Periodicals, Inc. Res Nurs Health 33:133–143, 2010
Effect of elongational flow on morphology and properties of polymer/CNTs nanocomposite fibers
Authors: Dintcheva N. Tz. , Arrigo R. , Morreale M. , La Mantia F. P. , Matassa R. , Caponetti E. 
Published: January 2010

AbstractCarbon nanotubes (CNTs) have been attracting increasing interest for the fabrication of polymer‐based nanocomposites because of their excellent properties. Traditional methods for the preparation of polymer/CNTs nanocomposites are in situ polymerization, solution blending, and melt mixing. The achievement of a good CNT dispersion and a percolation network is important in order to obtain better mechanical and electrical properties. However, the rheological behavior of polymer/CNTs systems, in particular regarding the extensional flow, has not been much investigated so far. In this work we present, for the first time, rheological data in non‐isothermal extensional flow and an investigation on the effect of the extensional flow upon the final properties of several polymer/CNTs systems was carried out as well. Extensional flow led to higher mechanical properties and higher melt strength, but only a slightly reduced breaking stretching ratio. This result could be particularly interesting in the view of potential industrial applications such as film blowing and spinning. Morphological analyses also showed higher degrees of dispersion and variation in the CNTs final dimensions. Copyright © 2010 John Wiley & Sons, Ltd.