bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ruthenium(II) Complexes Bearing Carboxylato and 2‐Oxocarboxylato Ligands
Authors: Müller Rainer , Hübner Eike , Burzlaff Nicolai 
Published: April 2004

AbstractThe syntheses of ruthenium(II) acetato and benzoato complexes [Ru(bdmpza)(O2CCH3)(PPh3)] (6) and [Ru(bdmpza)(O2CPh)(PPh3)] (7) [bdmpza = bis(3,5‐dimethylpyrazol‐1‐yl)acetate] are reported. The complexes 6 and 7 are synthesized in high yield from [Ru(bdmpza)Cl(PPh3)2] (1) and thallium acetate (2) or thallium benzoate (3). In a similar substitution reaction a benzoylformate complex [Ru(bdmpza){O2CC(O)Ph}(PPh3)] (8) is obtained from 1 and thallium benzoylformate (4). Reaction of 6 or 7 with benzoylformic acid also yields 8. In analogous reactions several 2‐oxocarboxylato ruthenium(II) complexes [Ru(bdmpza){O2CC(O)R}(PPh3)] (9: R = CH2CH2CO2H, 10: R = Me, 11: R = Et) can be obtained. The low‐spin ruthenium(II) complexes 8 to 11 exhibit a purple or brownish‐red colour caused by MLCT transitions and thus a HOMO−LUMO gap which is almost identical to that of high‐spin 2‐oxoglutarate dependent iron oxygenases. 6 crystallises as a water adduct, 6·H2O and 8 forms an acetonitrile adduct 12. Crystal structures of the water adduct 6·H2O and 8 were obtained. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Sugar Syrup Concentration Using Reverse Osmosis Membranes
Authors: Madaeni S.S. , Tahmasebi K. , Kerendi S.H. 
Published: April 2004

AbstractIn sugar manufacturing industries, initially dilute syrup is obtained from the cane sugar or beetroot, which should be concentrated. In many factories, sugar syrup concentration is carried out using evaporation. This process has two main problems. Firstly, it consumes a huge amount of energy due to high latent heat of water and secondly, heating may decompose the sugar molecules resulting in low‐quality and dark‐colored sugar. Low energy consuming reverse osmosis may be employed for concentrating sugar syrup without decomposing the molecules, resulting in high‐quality sugar with low cost. In this study different commercial reverse osmosis membranes (DS, DSII, PVD, FT30, BW30) and one nanofiltration membrane (NF45) were used for sugar syrup concentration. The results show that nanofiltration NF45 membrane has no effect on sugar syrup concentration. The rejections of sugar using DSII and PVD reverse osmosis membranes vary between 23 % and 33 % for different operating conditions. DS membrane rejected around 10 % of the sugar molecules in best conditions. FT30 membrane initially showed better performance (55 %). However, the rejection was decreased during time (minimum 7 %). For BW30 membrane, the rejection of sugar was better (60 %) compared to the other membranes used in this work. For two‐stage processes (i.e. the permeate of the first stage used as a feed for the second stage) the highest rejection (88 %) was obtained.
Fungal Biodegradation and Detoxification of Cork Boiling Wastewaters
Authors: Mendonça E. , Pereira P. , Martins A. , Anselmo A.M. 
Published: April 2004

AbstractThe ability of several fungal strains to degrade and to detoxify cork boiling wastewaters was investigated. The fungal strains used in this work were Sporothrix sp., Trichoderma koningii, Chrysonilia sitophila and Penicillium glabrum isolated from cork bark as well as Fusarium flocciferum and Phanerochaete chrysosporium. The results obtained in the degradation experiments carried out with each fungus showed that all fungi display similar abilities, with a chemical oxygen demand reduction of 54.2 % (± 4.7 %) attained within five days of incubation. F. flocciferum presented the highest value for the reduction of chemical oxygen demand of 62 %. In addition, a rise in pH values of around 3 units was detected with all the strains, except for Penicillium glabrum. Toxicity tests performed on Vibrio fischeri revealed that fungal treatment of the wastewaters causes the complete loss of toxicity in the cases of Sporothrix sp., T. koningii, P. chrysosporium and F. flocciferum. The other two tested strains were also able to detoxify the raw wastewaters, causing a ten‐fold decrease in toxicity. The results obtained in sequential biodegradation experiments with different pairs of fungi showed that although the increment in the COD reduction did not exceed 10 %, an important reduction in toxicity and a pH rise were attained.
Enhancement of Lead(II) Biosorption by Microalgal Biomass Immobilized onto Loofa (Luffa cylindrica) Sponge
Authors: Akhtar N. , Iqbal J. , Iqbal M. 
Published: April 2004

AbstractA unicellular green microalga, Chlorella sorokiniana, was immobilized on loofa (Luffa cylindrica) sponge and successfully used as a new biosorption system for the removal of lead(II) ions from aqueous solutions. The biosorption of lead(II) ions on both free and immobilized biomass of C. sorokiniana was investigated using aqueous solutions in the concentration range of 10–300 mg/L. The biosorption of lead(II) ions by C. sorokiniana biomass increased as the initial concentration of lead(II) ions increased in the medium. The maximum biosorption capacity for free and immobilized biomass of C. sorokiniana was found to be 108.04 and 123.67 mg lead(II)/g biomass, respectively. The biosorption kinetics were found to be fast, with 96 % of adsorption within the first 5 min and equilibrium reached at 15 min. The adsorption of lead(II) both by free and immobilized C. sorokiniana biomass followed the Langmuir isotherm. The biosorption capacities were detected to be dependent on the pH of the solution; and the maximum adsorption was obtained at a solution pH of about 5. The effect of light metal ions on lead(II) uptake was also studied and it was shown that the presence of light metal ions did not significantly affect lead(II) uptake. The loofa sponge‐immobilized C. sorokiniana biomass could be regenerated using 0.1 M HCl, with up to 99 % recovery. The desorbed biomass was used in five biosorption‐desorption cycles, and no noticeable loss in the biosorption capacity was observed. In addition, fixed bed breakthrough curves for lead(II) removal were presented. These studies demonstrated that loofa sponge‐immobilized biomass of C. sorokiniana could be used as an efficient biosorbent for the treatment of lead(II) containing wastewater.
Xylitol Production from D‐Xylose at Different Oxygen Transfer Coefficients in a Batch Bioreactor
Authors: Winkelhausen E. , Amartey S.A. , Kuzmanova S. 
Published: April 2004

AbstractConversion of D‐xylose to xylitol by Candida boidinii NRRL Y‐17213 was studied under anaerobic and oxygen limited conditions by varying the oxygen transfer coefficient kLa. Shake flask experiments were used to provide the preliminary information required to perform experiments in a bioreactor. The yeast did not grow under fully anaerobic conditions, but anaerobic formations of xylitol, ethanol, ribitol, and glycerol were observed as well as D‐xylose assimilation of 11 %. In shake flasks, with an initial D‐xylose concentration of 50 g/L, an increase in kLa from 8 to 46 h–1 resulted in a faster growth, higher rate of substrate uptake and lower yields of products. The highest xylitol productivity (0.052 g/L h) was attained at kLa = 8 h–1. At kLa = 46 h–1, 98.6 % of D‐xylose was consumed and mainly converted to biomass. Using 130 g/L D‐xylose, kLa was varied in the fermenter from 26 to 78 h–1. The percentage of consumed D‐xylose increased from 31 % at kLa = 26 h–1 to 93–94 % at all other aeration levels. Biomass yield increased with kLa, whereas ethanol, ribitol, and glycerol yields exhibited an opposite dependence on the oxygenation level. The most favorable oxygen transfer coefficient for xylitol formation, in the fermenter, was kLa = 47 h–1 when its concentration (57.5 g/L) surpassed ethanol accumulation by 3.6‐fold, and the glycerol plus ribitol by 10‐fold. Concurrently, xylitol yield and productivity reached 0.45 g/g and 0.26 g/L h, respectively. The volumetric xylitol productivity was affected more by changes in the aeration than the corresponding yield.
Effects of the Little Ice Age on avalanche boulder tongues in the French Alps (Massif des Ecrins)
Authors: Jomelli Vincent , Pech Pierre 
Published: April 2004

AbstractLichens of the subspecies Rhizocarpon geographicum s.l were measured on 25 avalanche boulder tongues in the Massif des Ecrins to elucidate the Little Ice Age history of avalanche activity. Results show: (1) an increase of lichen size from the median to the distal zone of deposits, and a decrease from the edges to the centre; (2) three types of lichen settlement. From the uppermost to the median zone, lichens are absent, because avalanche activity is very active. Down‐slope, lichens occur in two different zones: the median zone is colonized by 5–20 mm size lichens on sides of blocks protected from the abrasional action of avalanches, while in the distal zone lichen diameters are largest (>30 mm) and occur on all sides of the blocks.The spatial distribution of the lichens and their size according to elevation make it possible to distinguish different phases during which avalanche activity has increased. At high elevation, the avalanche activity was at a maximum before ad 1650 and between ad 1730 and 1830. During these two periods avalanches had sufﬁcient magnitude to reach the basal zone of the deposits. At low elevation since ad 1650 the magnitude and frequency of avalanches have declined. Copyright © 2004 John Wiley & Sons, Ltd.
Improving simple explicit methods for unsteady open channel and river flow
Authors: Burguete J. , García‐Navarro P. 
Published: April 2004

AbstractA rigorous study of the explicit Lax–Friedrichs scheme for its application to one‐dimensional shallow water flows is presented. The deficiencies of this method are identified and the way to overcome them are presented. It is compared to the explicit first order upwind scheme and to the explicit second order Lax–Wendroff scheme by means of the simulation of several test cases with exact solution. All three schemes in their best balanced version are applied to the simulation of a real river flood wave leading to very satisfactory results. Copyright © 2004 John Wiley & Sons, Ltd.
On the application of slip boundary condition on curved boundaries
Authors: Behr Marek 
Published: April 2004

AbstractHydrodynamic simulations of sloshing phenomena often involve the application of slip boundary condition at the wetted surfaces. If these surfaces are curved, the ambiguous nature of the normal vector in the discretized problem can interfere with the application of such a boundary condition. Even the use of consistent normal vectors, preferred from the point of view of conservation, does not assure good approximation of the continuum slip condition in the discrete problem, and non‐physical recirculating flow fields may be observed. As a remedy, we consider the Navier slip condition, and more successfully, the so‐called BC‐free boundary condition. Copyright © 2004 John Wiley & Sons, Ltd.
Nutritional evaluation of some Nigerian wild seeds
Authors: Oboh Ganiyu , Ekperigin M. Mofoluso 
Published: April 2004

AbstractSome wild seeds, namely Parkia biglobosa, Tetracarpidum conophorum, Pentaclethra macrophylla, Irvingia gabonensis, Afzelia africana, Prosporis africana and Monodora myristica, were randomly collected from various parts of Nigeria and analyzed with regard to their proximate, mineral, antinutrient composition and zinc bioavailability. The results revealed that the seeds had high protein (6.5–24.2%), fat (19.0–58.5%), mineral (Mg, Fe, Zn, Mn, Ca, Na, K, P) and phytate (1043.6–2905.2 mg/100 g) contents, while the cyanide content was low (3.7–6.4 mg/kg). However, Co, Pb and Ni were not detected in all the samples. The calculated [Ca] [phytate]/[Zn] molar ratios (which is the best index for predicting Zn bioavailability) for all the seeds revealed that Parkia biglobosa, Irvingia gabonensis and Prosporis africana had a calculated molar ratio above 0.50 mol/kg (critical level), thus indicating reduced bioavailability of Zn to a critical level. In view of the high fat, protein, mineral and low cyanide contents, the high phytate content would not be expected to reduce bioavailability of Zn in some of the wild seeds (Afzelia africana, Pentaclethra macrophylla and Monodora myristica). These wild seeds could be good nutrient sources if integrated fully into human and animal nutrition. However, further studies will be carried out on the protein quality and toxicological potentials of these wild seeds.
Moisture sorption characteristics of rice flour
Authors: Durakova Albena G. , Menkov Nikolay D. 
Published: April 2004

AbstractMoisture equilibrium data (adsorption and desorption) of rice flour were determined using the static gravimetric method of saturated salt solutions at three storage temperatures: 10, 20 and 30°C. The range of water activities for each temperature was from 0.11 to 0.85. Equilibrium moisture content decreased with increase in storage temperature at any given water activity. The experimental data were fitted to four mathematical models (modified Oswin, modified Halsey, modified Chung‐Pfost and modified Henderson). The monolayer moisture content was estimated from sorption data using the Brunauer‐Emmett‐Teller (BET) equation. The isosteric heats of sorption were evaluated using Clausius‐Clapeyron equation.
Wheat flour confectionery products as a source of inorganic nutrients: Zinc and copper contents in hard biscuits
Authors: Šebečić Blaženka , Vedrina‐Dragojevic Irena 
Published: April 2004

AbstractCereal‐based confectionery products being consumed through whole human life are considered mainly to be a source of carbohydrates, that is energy, although cereals are a rich source of minerals as well. To evaluate some hard biscuits produced in Croatia as a source of different trace elements in nutrition, in this study Zn and Cu contents were determined in classic wheat flour biscuits and in dietetic biscuits enriched with whole wheat grain flour or whole wheat grain grits, soya flour and skimmed milk. Zn was determined by flame atomic absorption spectrometry (AAS); Cu was determined by inductively coupled plasma atomic emission spectroscopy (ICP‐AES). The results show that the Zn content in different kinds of biscuits ranges from 5.89 up to 17.64 mg/kg and the Cu content ranges from 1.15 up to 2.79 mg/kg depending on the type of wheat milling products and mineral content of other ingredients used. Enriched dietetic biscuits produced from wheat flour type 850 and whole wheat grain flour and/or soya flour and skimmed milk were almost 200% and 150% higher in Zn and Cu, respectively, in comparison to classic white wheat flour biscuits and can be considered as good sources of Zn and Cu in nutrition.
Scale and scope economies in nursing homes: A quantile regression approach
Authors: Christensen Eric W. 
Published: April 2004

AbstractNursing homes vary widely between facilities with very few beds and facilities with several hundred beds. Previous studies, which estimate nursing home scale and scope economies, do not account for this heterogeneity and implicitly assume that all nursing homes face the same cost structure. To account for heterogeneity, this paper uses quantile regression to estimate cost functions for skilled and intermediate care nursing homes. The results show that the parameters of nursing home cost functions vary significantly by output mix and across the cost distribution. Estimates show that product‐specific scale economies systematically increase across the cost distribution for both skilled and intermediate care facilities, with diseconomies of scale in the lower deciles and no significant scale economies in the higher deciles. As for ray scale economies, estimates show economies of scale in the lower deciles and diseconomies of scale or no significant scale economies at higher deciles. The estimates also show that scope economies exist in the lower cost deciles and that no scope economies exist in the higher cost deciles. Additionally, the degree of scope economies monotonically decreases across the deciles. Copyright © 2003 John Wiley & Sons, Ltd.
The impact of quality on the demand for outpatient services in Cyprus
Authors: Hanson Kara , Yip Winnie C. , Hsiao William 
Published: April 2004

AbstractHealth policy reforms in a number of countries seek to improve provider quality by sharpening the incentives they face, for example by exposing them to greater competition. For this to succeed, patients must be responsive to quality in their choice of provider. This paper uses data from Cyprus to estimate the effect of quality on patients' choice between public and private outpatient care. It improves on the existing literature by using a more comprehensive set of quality attributes which allows the dimensions of quality that have the largest effect on patient choice of provider to be identified. We also introduce an innovative way of measuring patients' perceptions of quality in a household survey. We find that patients' choice of provider is sensitive to quality, and that interpersonal quality is more important than either technical quality or system‐related factors. Copyright © 2004 John Wiley & Sons, Ltd.
Estimation of snow depth over open prairie environments using GOES imager observations
Authors: Romanov Peter , Tarpley Dan 
Published: April 2004

AbstractWe assess the potential for estimating snow depth using observations in the visible and infrared spectral bands from the imager instrument onboard the Geostationary Operational Environmental Satellites (GOES). The approach makes use of a correlation between depth of the snowpack and satellite‐derived subpixel fractional snow cover over non‐forested and sparsely forested areas. To retrieve the snow depth we propose a simple analytical formula approximating the statistical relationship between the snow depth and the snow fraction.The primary focus of this study was the US Great Plains and Canadian prairies area. Daily maps of snow depth at a spatial resolution of 4 km have been produced for this region for four winter seasons from late 1999 to the beginning of 2003. Validation of the algorithm developed was performed through comparison of the satellite‐based product with snow depth measurements made at first‐order synoptic stations, US Cooperative Network stations and Canadian climate stations. The accuracy of snow depth retrievals was found to be about 30% of the observed snow depth for snow depths below 30 cm. Copyright © 2004 John Wiley & Sons, Ltd.
Validation of VEGETATION, MODIS, and GOES + SSM/I snow‐cover products over Canada based on surface snow depth observations
Authors: Simic Anita , Fernandes Richard , Brown Ross , Romanov Peter , Park William 
Published: April 2004

AbstractThe ability to map the areal depletion of snow accurately is important for operational decision making (e.g. reservoir management), for correct specification of boundary conditions in numerical weather‐prediction models, and for modelling atmospheric, hydrological and ecological processes. A number of satellite‐derived snow‐cover products are available in real time; however, these can differ considerably due to variations in sensor and platform characteristics, data pre‐processing methods, and the particular snow‐cover classification algorithms employed. This article evaluates the performance of three daily snow‐cover products over Canada: (1) Terra Moderate Resolution Imaging Spectroradiometer (MODIS) snow‐cover maps provided at 500 m spatial resolution for 2001; (2) National Oceanic Atmospheric Administration (NOAA) GOES + SSM/I snow maps provided at 4 km resolution for 2001 (∼30 km resolution SSM/I data were used for cloud‐covered areas); (3) SPOT‐4 VEGETATION (VGT) snow maps derived at 1 km resolution for 2000. An evaluation of the snow‐cover products with daily surface snow depth observations collected from almost 2000 meteorological stations across Canada revealed that the VGT snow product used in this study may not be suitable for snow mapping in Canada because of a significant bias towards mapping snow‐free conditions. The MODIS and NOAA products showed similar reasonable levels of agreement with ground data, ranging from approximately 80% to 100% on a monthly basis. Somewhat lower agreement was found in January, when solar zenith angles are large, suggesting that better correction for tree and surface shadow effects is needed in current snow‐cover mapping algorithms. The lowest agreement was seen during snowmelt, mainly in forest areas. Comparison of MODIS agreement statistics between sparse and dense conifer regions indicated that the effect of non‐representativenes of surface snow depth observations was on the order of 10% disagreement. The NOAA product was found to be the most consistent among land cover types and had the highest percentage of cloud‐free pixels. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of the El Niño–southern oscillation on temperature, precipitation, snow water equivalent and resulting streamflow in the Upper Rio Grande river basin
Authors: Lee Songweon , Klein Andrew , Over Thomas 
Published: April 2004

AbstractSnowmelt runoff dominates streamflow in the Upper Rio Grande (URG) basin of New Mexico and Colorado. Annual variations in streamflow timing and volume at most stations in the region are strongly influenced by the El Niño–southern oscillation (ENSO) through its modulation of the seasonal cycles of temperature and precipitation, and hence on snow accumulation and melting. After removing long‐term trends over the study period (water years 1952–99), the dependence of monthly temperature, precipitation, snow water equivalent (SWE) at snowcourse stations, and streamflow throughout the URG on ENSO was investigated using composite analyses of the detrended residuals and through dependence of the residuals on the Climate Prediction Center southern oscillation index during the preceding summer and fall. The climate of La Niña years was found to differ significantly from either El Niño or neutral years. Moreover, significant climatological ENSO‐related effects are confined to certain months, predominantly at the beginning and end of the winter season. In particular, March of La Niña years is significantly warmer and drier than during either El Niño or neutral years, and November of El Niño years is significantly colder and wetter. Differences in temperature and precipitation lead to significant differences in SWE and streamflow in the URG between the three ENSO phases. Copyright © 2004 John Wiley & Sons, Ltd.