bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of soil water repellency in the course of isothermal drying and upon pH changes in two urban soils
Authors: Bayer Julia V. , Schaumann Gabriele E. 
Published: July 2007

AbstractThe potential influence of pH on water repellency in soils has already been mentioned in some studies, but no clear correlation between these parameters has been found to date. In addition, although correlations of water content and water repellency have been found in numerous studies, the influence of drying and subsequent storage conditions on water repellency are still unclear. In this study, a series of samples showing water repellent and wettable conditions respectively at field moist states from two urban locations were compared regarding two main aspects: (i) the influence of artificial pH‐changes on their wetting behaviour and (ii) sample wettability changes during drying for different drying temperatures. The assumption made in a study by Hurraß and Schaumann (2006) on the same sample site, that differences in wettability of closely neighboured samples from one sample location can be interrelated with differences in pH, was confirmed. However, in contrast to the assumption that rising pH will improve the wettability and decreasing pH will intensify water repellency, we found a maximum in water repellency at a pH above the initial pH. The results from drying samples at different temperatures confirmed the dependence of water repellency development on the drying temperature. Additionally, we could confirm the conclusion from previous studies that the water content alone cannot explain the water content–WDPT (water drop penetration time) relationship. The results from drying and pH changes show that some location specific factors, like the number of pH active functional groups, may be relevant for sample wettability. As additional mechanism, which may be partly antagonistic to the influence of the water content, we assume temperature‐dependent conformational changes in SOM (Soil Organic Matter). It seems that aspects of these conformational changes may additionally be governed by pH in one of our two locations. Copyright © 2007 John Wiley & Sons, Ltd.
Extent and persistence of water repellency in north‐western Spanish soils
Authors: Rodríguez‐Alleres M. , Benito E. , de Blas E. 
Published: July 2007

AbstractThe aim of this work was to examine the distribution and persistence of water repellency in soils of different texture in the Spanish humid region as a function of land use and management. At 34 locations, samples of soil under different land uses (maize crop, grassland, Pinus pinaster forest and Eucalyptus globulus forest) and various geological materials were collected from the surface layer (0–5 cm). In addition, P. pinaster and E. globulus forest soil samples were collected at four different depths (0–5, 5–10, 10–20 and 20–40 cm) at 10 of the previous locations. Water repellency was determined by using the water drop penetration time (WDPT) test on field‐moist samples (actual WDPT) collected during summer and was compared with the values for samples dried at 25 and 105 °C (potential WDPT).Based on the results, the prevailing vegetation and land use dictate the development and persistence of surface water repellency in the studied soils. The E. globulus forest soil samples were found to be the most water repellent, followed by the P. pinaster forest samples (73 and 64%, respectively, with actual WDPT > 6 h); on the other hand, 79% of the field‐moist samples from soils under maize and 71% of those under grass were non‐repellent. The influence of vegetation on water repellency was found to be related to the type and content of soil organic matter. Each type of vegetation resulted in significant differences in surface water repellency between soils with sandy‐loam texture and also between soils with loam or silt‐loam texture; repellency was higher in the samples with coarser textures. The persistence of water repellency decreased with increasing soil depth, the decrease being more marked in the finer‐textured soils than in the coarser ones and also in the pine forest soils than in the eucalypt forest soils. The water repellency of most of the samples dried at 25 and 105 °C was similar to that of the field‐moist samples collected during the dry period (r = 0·90, p < 0·01). Copyright © 2007 John Wiley & Sons, Ltd.
Water repellence of soils: new insights and emerging research needs
Authors: Doerr S. H. , Ritsema C. J. , Dekker L. W. , Scott D. F. , Carter D. 
Published: July 2007

AbstractAn increasing awareness of the occurrence and implications of soil water repellence has caused a surge in research activity addressing this phenomenon in recent years. This has involved not only the disciplines of hydrology, soil, and related environmental sciences, but increasingly also biology, chemistry, physics, and surface sciences, which has allowed elucidation of the causes and behaviour of soil water repellence based on first order principles. Furthermore, novel approaches and advances in technology have allowed examination of its causes and implications at increasingly coarse and fine spatial and temporal scales.The 19 papers presented in this special issue exemplify this trend by bringing together studies from diverse disciplines and presenting the latest advances regarding the origin, occurrence, controls, hydrological effects, and amelioration of soil water repellence. Here we aim to summarize, evaluate and set into context some of the new insights arising from these studies and also attempt to identify the key current and likely future research gaps related to water repellence in soils. Copyright © 2007 John Wiley & Sons, Ltd.
Implications of ideas on super‐hydrophobicity for water repellent soil
Authors: McHale G. , Shirtcliffe N. J. , Newton M. I. , Pyatt F. B. 
Published: July 2007

AbstractWater repellence is an important factor in soil erosion due to its role in inhibiting the re‐establishment of vegetation after fire and due to its enhancement of run‐off. Water repellence is studied across a range of diverse disciplines, such as chemistry, materials, textiles and soil and reclamation science. In recent years many basic studies of water repellence of materials have focused on the role of the sub‐mm surface topography of a material in modifying the intrinsic hydrophobicity imparted by the surface chemistry to create super‐hydrophobicity. In this report, we first illustrate the types of hydrophobic effects created by a suitable coupling of small scale surface topography with surface chemistry using three materials: an etched metal, a foam and a micro‐fabricated pillar structure. These experiments demonstrate the general applicability of the ideas and suggest that they could apply to a granular material such as, a fine sandy soil, particularly when the grains have become coated with a hydrophobic layer. This applicability is confirmed by contact angle measurements of droplets of water on hydrophobic sand. A theoretical model describing the application of these ideas in a loose‐packed, but regular, array of uniform spherical grains is then presented and discussed. When the grains are in a dry state initially, the effect of the surface is to increase the apparent water repellence as observed through the contact angle. However, when the spaces between the grains are filled with water, the effect is to provide greater wetting. To qualitatively confirm the enhancement of contact angle caused by the granular structure, model surfaces using 600 and 250 µm hydrophobic glass beads were created. On these surfaces, the contact angle of droplets of water was increased from 108° to 126° and 140° , respectively. Copyright © 2007 John Wiley & Sons, Ltd.
A comprehensive theoretical study on the hydrolysis of carbonyl sulfide in the neutral water
Authors: Deng Chao , Li Qiang‐Gen , Ren Yi , Wong Ning‐Bew , Chu San‐Yan , Zhu Hua‐Jie 
Published: July 2007

AbstractThe detailed hydration mechanism of carbonyl sulfide (COS) in the presence of up to five water molecules has been investigated at the level of HF and MP2 with the basis set of 6‐311++G(d, p). The nucleophilic addition of water molecule occurs in a concerted way across the CS bond of COS rather than across the CO bond. This preferential reaction mechanism could be rationalized in terms of Fukui functions for the both nucleophilic and electrophilic attacks. The activation barriers, ΔH, for the rate‐determining steps of one up to five‐water hydrolyses of COS across the CS bond are 199.4, 144.4, 123.0, 115.5, and 107.9 kJ/mol in the gas phase, respectively. The most favorable hydrolysis path of COS involves a sort of eight‐membered ring transition structure and other two water molecules near to the nonreactive oxygen atom but not involved in the proton transfer, suggesting that the hydrolysis of COS can be significantly mediated by the water molecule(s) and the cooperative effects of the water molecule(s) in the nonreactive region. The catalytic effect of water molecule(s) due to the alleviation of ring strain in the proton transfer process may result from the synergistic effects of rehybridization and charge reorganization from the precoordination complex to the rate‐determining transition state structure induced by water molecule. The studies on the effect of temperature on the hydrolysis of COS show that the higher temperature is unfavorable for the hydrolysis of COS. PCM solvation models almost do not modify the calculated energy barriers in a significant way. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008
Thermodynamic calculations for molecules with asymmetric internal rotors. II. Application to the 1,2‐dihaloethanes
Authors: Wong Bryan M. , Fadri Maria M. , Raman Sumathy 
Published: July 2007

AbstractThe thermodynamic properties of three halocarbon molecules relevant in atmospheric and public health applications are presented from ab initio calculations. Our technique makes use of a reaction path‐like Hamiltonian to couple all the vibrational modes to a large‐amplitude torsion for 1,2‐difluoroethane, 1,2‐dichloroethane, and 1,2‐dibromoethane, each of which possesses a heavy asymmetric rotor. Optimized ab initio energies and Hessians were calculated at the CCSD(T) and MP2 levels of theory, respectively. In addition, to investigate the contribution of electronically excited states to thermodynamic properties, several excited singlet and triplet states for each of the halocarbons were computed at the CASSCF/MRCI level. Using the resulting potentials and projected frequencies, the couplings of all the vibrational modes to the large‐amplitude torsion are calculated using the new STAR‐P 2.4.0 software platform that automatically parallelizes our codes with distributed memory via a familiar MATLAB interface. Utilizing the efficient parallelization scheme of STAR‐P, we obtain thermodynamic properties for each of the halocarbons, with temperatures ranging from 298.15 to 1000 K. We propose that the free energies, entropies, and heat capacities obtained from our methods be used to supplement theoretical and experimental values found in current thermodynamic tables. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008
Modified frames with block size 3
Authors: Cao H. , Wu Y. , Zhou H. 
Published: July 2007

AbstractA modified (k, λ)‐frame of type gu is a modified (k, λ)‐GDD whose blocks can be partitioned into holey parallel classes, each of which is with respect to some group. Modified frames can be used to construct some other resolvable designs such as resolvable group divisible designs and semiframes. In this article, we shall investigate the existence of modified frames with block size 3. © 2007 Wiley Periodicals, Inc. J Combin Designs 16: 351–363, 2008
Stereoselective hybrid catalysts: new opportunities
Authors: Mihovilovic Marko D 
Published: July 2007

AbstractThe combination of biotransformations and metal‐assisted catalysis within hybrid systems represents a promising strategy to extend the repertoire of reactions enabled in a biomolecular environment. Both covalent catalytic entities and supramolecular assemblies have been created recently to mediate transformations otherwise difficult to perform in ‘classical’ biocatalysis. In this context, various biopolymers can serve as ligand spheres simultaneously acting as chiral inducers. In particular, modular approaches embedding novel metal‐based catalytic centers via an affinity interaction are highly appealing, as this technology may serve as a versatile platform to incorporate diverse reactivities in a biological matrix in a stereoselective fashion. Copyright © 2007 Society of Chemical Industry
Catalytic conversion of waste plastics: focus on waste PVC
Authors: Keane Mark A 
Published: July 2007

AbstractEffective waste management must address waste reduction, reuse, recovery/recycling and, as the least progressive option, waste treatment. The increase in plastic waste production is a serious environmental issue. Plastics consumption continues to grow and while plastic recycling has seen a significant increase since the early 1990s, consumption still far exceeds recycling. Waste plastic can, however, serve as a potential resource and, with the correct treatment, can be reused or serve as hydrocarbon raw material or as a fuel. PVC, highly versatile with many applications, is non‐biodegradable and has a high Cl content (56% of the total weight). Waste PVC incineration is highly energy demanding and can result in the formation of toxic chloro‐emissions with adverse ecological, environmental and public health impacts. The Cl component must be removed from any waste PVC derived gas or oil before it can be used. An overview of the existing waste plastic treatment technologies is provided with an analysis of the available literature on thermal and catalytic PVC degradation. Thermal degradation results in random scissioning of the polymer chains generating products with varying molecular weights and uncontrolled Cl content. There is a dearth of literature dealing with the catalytic dechlorination of PVC. A case study is presented to illustrate the role heterogeneous catalysis can play in PVC waste treatment. The efficacy of Pd/Al2O3 to promote PVC dechlorination is demonstrated, where a significant decrease (by up to a factor of 560) in the liquid fraction Cl content is recorded in addition to differences (relative to thermal degradation) in the gas phase product, i.e. higher C1C4 content with preferential alkane formation. Copyright © 2007 Society of Chemical Industry
Aerobic biological treatment of waste‐ waters containing dichloromethane
Authors: Moura Sandra C , Jorge Ruben Ferreira , Duque Anouk , Boaventura Rui AR , Castro Paula ML 
Published: July 2007

AbstractBACKGROUND: Volatilization has been advanced as one of the predominant phenomena contributing to volatile organic carbon emissions from wastewater treatment plants (WWTPs). In this study, strategies for minimizing such air stripping losses when treating a liquid stream containing dichloromethane (DCM), aiming at decreasing the overall emission inventory from WWTPs, were investigated.RESULTS: System R1, consisting of a continuous flow stirred tank reactor (CSTR) treating a liquid stream containing DCM at a concentration of 12 mmol dm−3 presented a biodegradation efficiency (BE) of 68%, based upon chloride release, with 10% of measurable losses, mainly due to volatilization, and 22% of unmeasurable losses. System R2 introduced operational designs aiming at decreasing DCM volatilization. In Experiment R2.1, a biotrickling filter, through which the air stripped from the CSTR was driven, was introduced leading to a reduction from 10% to 7% on the measurable losses. In Experiment R2.2, the air stripped from the CSTR was recirculated at a flow rate of 2.4 dm3 h−1 through the reactor medium before entering the biotrickling filter. The BE was improved from 69% to 82% and the losses associated with air stripping were successfully reduced to 2%. The proposed design, including air recirculation and the biotrickling filter, increased the ratio between the biodegradation rate and the volatilization rate from 7 to 41.CONCLUSIONS: Recirculation of the gaseous effluent through the reactor medium, which allowed for higher residence time within the bioreactor, was shown to be a successful strategy for improving the treatment process, thus minimizing DCM volatilization losses. Copyright © 2007 Society of Chemical Industry
Compressibility of gastrointestinal tract tumors during transabdominal sonographic examination: A clue to the diagnosis of gastrointestinal lymphoma
Authors: Fujii Yasutomo , Taniguchi Nobuyuki , Koibuchi Harumi , Yasuda Yoshikazu , Nagai Hideo 
Published: July 2007

AbstractPurposeTo evaluate the use of sonography in the assessment of compressibility of the affected bowel in the differential diagnosis of gastrointestinal (GI) lymphoma.MethodsThirty‐two cases of advanced gastric cancer, 28 cases of advanced colon cancer, 7 cases of gastric lymphoma, and 6 cases of colon lymphoma were included in the study. To assess the compressibility of the affected bowel, a transducer was used to exert external compression. Deformation of the tumor and its lumen by compression was considered to indicate positive compressibility.ResultsCompressibility was absent in advanced gastric and colon cancer but was present in 11/13 (85%) cases of GI lymphoma. In the diagnosis of GI lymphoma, compressibility showed 85% (11/13) sensitivity, 97% (58/60) specificity, and 95% (69/73) overall accuracy.ConclusionCompressibility of the affected bowel is a useful clue in the diagnosis of GI lymphoma. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Sonographic evaluation of entheseal sites of the lower extremity in patients undergoing hemodialysis
Authors: Kerimoglu Ulku , Hayran Mutlu , Ergen Fatma Bilge , Kirkpantur Alper , Turgan Cetin 
Published: July 2007

AbstractPurposeTo evaluate the entheseal sites of the lower extremities in patients on hemodialysis using the Glasgow Ultrasound Enthesitis Scoring System (GUESS) and to correlate the findings with the duration of hemodialysis and patient scores.MethodsForty‐nine patients who were on hemodialysis for at least 2 years were grouped according to duration of hemodialysis. Total GUESS scores; total enthesophyte, erosion, and bursitis scores; and tendon thicknesses were calculated, compared between groups, and correlated with duration of dialysis.ResultsThere was a statistically significant correlation between duration of hemodialysis and total GUESS score (p < 0.001, r = 0.81) and also between the total enthesophyte and erosion scores (p < 0.001). If severe enthesitis was defined as a total GUESS score of more than 18, receiver operating characteristic (ROC) curve analysis revealed that a cutoff point of 10 years for the duration of hemodialysis would predict severe enthesal damage with 83% sensitivity and 93% specificity (area under the ROC curve, 0.92; 95% confidence interval, 0.83–1.00).ConclusionHemodialysis results in entheseal site changes that worsen with extended duration of hemodialysis, especially after 10 years. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2007
What enables innovation in the private sector? Lessons from the development of salt‐tolerant hybrid rice
Authors: Reece J. David 
Published: July 2007

AbstractUnder what circumstances can a private company succeed in developing new crops? This paper examines the experience of an Indian seed company that sought to use an advanced new technology (molecular breeding) to develop a salt‐tolerant form of hybrid rice. It demonstrates that the company's success was made possible by its effective linkages with national and international institutions, which mean that the company received indispensable inputs to its work; namely DNA sequence data from the global public domain and germplasm from the Indian public sector. Provision of these inputs was not mediated by a market system: indeed, recent changes that tend to make such interactions subject to market forces, notably the commodification of germplasm, have increased transaction costs and been a source of inefficiency. At the same time, the internal characteristics of different parts of the firm meant that (i) a number of technically demanding tasks were successfully completed; but (ii) progress was slower than could reasonably have been expected and (iii) at one point the project suffered a severe setback. These experiences confirm the innovation systems framework and also highlight the critical importance of the internal culture of a firm in determining success or failure in innovation. Interestingly, they also demonstrate that key aspects of organisational culture may vary between different parts of the same company. Copyright © 2007 John Wiley & Sons, Ltd.
The case for accelerating profit‐making at the base of the pyramid: what could and should the donor community be seeking to do, and what results should it expect?
Authors: Fitch Bob , Sorensen Leif 
Published: July 2007

AbstractDonors increasingly acknowledge that, without the participation of the private sector, achievement of the Millennium Development Goals is unlikely. Up until recently, priority has been given to improving the business enabling environment in developing countries, so as to remove unnecessary impediments to profit‐making activity. Whilst this approach has undoubted merit it does not yet seem to be stimulating change at the pace or scale required. This paper argues that there is now a clear case for directly engaging international business in the poverty reduction agenda. It argues that such efforts will have the greatest development impact where profit‐making is the driving force, and considers how the impact of such initiatives might best be measured. Copyright © 2007 John Wiley & Sons, Ltd.
Trade facilitation, regulatory quality and export performance
Authors: Iwanow Tomasz , Kirkpatrick Colin 
Published: July 2007

AbstractThe objective of this paper is to quantify the potential gains in trade performance from the implementation of trade facilitation reform. The study applies a gravity model augmented with trade facilitation, regulatory quality and infrastructure indicators to assess the impact of trade facilitation and other trade‐related constraints on export performance. Quantitatively, our results suggest that a 10 per cent improvement in trade facilitation would yield an increase in exports of about 5 per cent. Identical percentage improvements in the regulatory environment and in the quality of infrastructure provision would result in increases of 9–11 per cent and 8 per cent, respectively. The results confirm that while trade facilitation can contribute to improved export performance, improvements in the quality of the regulatory environment and the basic transport and communications infrastructure are equally or more important, in facilitating export growth. The conclusion is that trade facilitation alone is unlikely to result in a significant improvement in export performance. Copyright © 2007 John Wiley & Sons, Ltd.