bluuebunny/crossref_metadata_2025 huggingface dataset:
Parameter Estimation for Soil Hydraulic Properties Using Zero‐Offset Borehole Radar
Authors: Rucker Dale F. , Ferré Ty P. A.
Published: July 2010

Inverse methods to obtain soil hydraulic parameters are becoming increasingly popular, due to their more rapid, complete, and robust estimations of hydraulic parameters compared with traditional direct methods. We present a method to infer hydraulic parameters based on first arrival travel time measurements made with zero‐offset borehole ground penetrating radar (BGPR). Borehole ground penetrating radar offers many advantages for field‐scale monitoring of transient processes including the ability to measure rapidly, over relatively large soil volumes, with high temporal resolution and to great depths. The BGPR measurements are used to infer the position of the wetting front during infiltration. The analysis makes use of critical refraction at the edge of the wetting front, which gives rise to a linear increase in BGPR travel time with time as the wetting front passes beneath the antennae. The slope of this response is used directly to calculate the hydraulic conductivity. We demonstrate that unique determination of the van Genuchten α and n parameter is not possible with BGPR data alone; at least one pressure head measurement in the dry range (early time) is required. We employ a nonlinear least squares parameter estimation code to obtain the optimal α and n parameters for synthetic data. The method could potentially be applied to areas of artificial recharge in an infiltration basin, natural recharge in an ephemeral stream, or agricultural settings where the surface is flooded with irrigated water.
Grass Barrier and Vegetative Filter Strip Effectiveness in Reducing Runoff, Sediment, Nitrogen, and Phosphorus Loss
Authors: Blanco-Canqui Humberto , Gantzer C. J. , Anderson S. H. , Alberts E. E. , Thompson A. L.
Published: July 2010

Addition of switchgrass (Panicum virgatum) barriers to vegetative filter strips (FS) shows potential as conservation practice. This study evaluates the comparative effectiveness of three conservation practices in reducing runoff, sediment, N, and P losses from 1.5‐ by 16‐m plots on an Aeric Epiaqualf. Three practices compared are a traditional fescue (Festuca arundinacea) filter strip (Fescue‐FS), a switchgrass barrier in combination with the Fescue‐FS (B‐Fescue‐FS) and a switchgrass barrier in combination with a native grass and forbs species filter strip (B‐Native‐FS). This study also predicts transport of sediment, N, and P in Fescue‐FS and B‐Fescue‐FS. Fescue‐FS and B‐Fescue‐FS of equal widths (0.7 m) significantly reduced runoff and sediment transport as compared with a continuous cultivated fallow (CCF) treatment, but B‐Fescue‐FS was more effective for reducing runoff (p < 0.05) and sediment (p < 0.01) transport. B‐Fescue‐FS was also more effective than Fescue‐FS for reducing losses of organic N, NO3–N, NH4–N, particulate P, and PO4–P (p < 0.01). Fescue‐FS and B‐Native‐FS were equally effective for reducing runoff, sediment, and nutrient loss. Effectiveness of FS increased with distance with 18% of runoff, 92% of sediment, and 71% of nutrient leaving the source area being reduced in the first 4 m of the FS. An equation to predict sediment associated with runoff ponding above barriers explained approximately 70% of the variability between measured and predicted values of sediment, organic N, and particulate P transport. Combination of switchgrass barriers with FS is an effective alternative to Fescue‐FS alone for reducing sediment and nutrients in runoff.
Soil Berms as an Alternative to Steel Plate Borders for Runoff Plots
Authors: Blanco-Canqui Humberto , Gantzer C. J. , Anderson S. H. , Thompson A. L.
Published: July 2010

Steel plates are often used to border runoff‐erosion plots, but they are difficult to install and are expensive. This study assessed the effectiveness of using polyacrylamide (PAM; 2‐propenamide, homopolymer) treated soil with and without geotextile fabric (GF) for soil berm plot borders in laboratory and field conditions. Hemispherically shaped soil berms of 250 mm wide by 150 mm high were constructed in erosion boxes. Erosion and runoff from untreated berms, berms treated with 9 kg ha−1 of PAM, and berms treated with 9 kg ha−1 of PAM and covered with GF (PAM‐GF) were measured under simulated rainfall. A dry simulation run was conducted for 1 h followed by a wet simulation run after 24 h under field conditions. The PAM‐GF reduced soil erosion from berms by 99% when compared with the untreated soil berm (control). Use of PAM alone reduced erosion from berms by ≈84%; however, erosion with PAM increased rapidly with time. Effectiveness of PAM alone decreased for reducing soil loss from 94% in the first 10 min of the 1‐h dry run to 27% by the end of the 1‐h wet run in field conditions. Although some runoff occurred from berms into the plots, this was insignificant for plot‐to‐berm ratios ≥10:1(P < 0.01). Results show that soil berms treated with PAM and GF reduced erosion to nondetectable levels. The cost for soil berm construction is about 10% of that for steel plate plot borders. The PAM‐GF treated soil berms can be an economical alternative to conventional steel plate plot borders especially for short‐term runoff studies.
Surface Clogging in an Intermittent Stratified Sand Filter
Authors: Rodgers M. , Mulqueen J. , Healy M. G.
Published: July 2010

Accumulation of biomass and deposition of suspended solids at the surface of a sand filter can lead to clogging of the filter media. A laboratory intermittent sand filter column, which included three sand strata, was operated for a period of 806 d before failure occurred through surface clogging. Upon dismantling the column, the cause and effects of the surface clogging were investigated. The main mechanism responsible for sand clogging appeared to be biomass buildup. Maximum loss on ignition of filter media samples was 2.35%, and it occurred in the upper 0.01 m of the sand. There was a reduction in field‐saturated hydraulic conductivity in the top 0.01 m of the upper sand stratum from a value of 1.9 × 10−3 ± 1.7 × 10−4 m s−1 (for virgin sand with an effective size, d10, of 0.45 mm) to 3.5 × 10−5 ± 7.5 × 10−6 m s−1 The soil‐water characteristic curve, which relates the volumetric water content (θv) to the soil suction, also reflected the changes in the filter media due to clogging. The water‐holding capacity greatly increased as biomass accumulated in the filter media. Scanning electron microscopy (SEM) confirmed the existence of a clogging organic layer on the surface of the top sand layer.
Disappearance of Aluminum Tridecamer from Hydroxyaluminum Solution in the Presence of Humic Acid
Authors: Yamaguchi Noriko , Hiradate Syuntaro , Mizoguchi Masaru , Miyazaki Tsuyoshi
Published: July 2010

We investigated the influences of humic acid on the removal of Al tridecamer (Al13) from a hydroxyaluminum (HyA) solution at various humic acid/Al ratios. The Al species contained in the solution were analyzed by using a liquid‐state 27Al‐NMR and an atomic absorption spectrometer and fractionated into three Al species: (i) Al13, (ii) Al monomer and dimer (AlSYM), and (iii) other undefined species including aggregated/precipitated Al (AlNON). By the addition of humic acid to the HyA solution, the concentration of Al13 was rapidly decreased within 0.007 d (10 min). The decrease in Al13 and the increase in AlNON were more pronounced at a higher humic acid/Al ratio. When the molar ratio of humic acid carboxylic groups to Al exceeded 0.8, Al13 was undetected from solution within 0.007 d. The formation of Al13–humic acid complexes and the aggregation/precipitation of those complexes were a predominant mechanism in removing aqueous Al13 at the early stage of the reaction. Approximately 10 mol of carboxylic groups in humic acid were required to remove 1 mol of Al13 from the HyA solution. Aqueous Al13 had greater preference in precipitating with humic acid than AlSYM After 5 to 570 d of aging, the concentration of Al13 and AlNON also decreased and increased, respectively, both in the presence and absence of humic acid. In conclusion, aqueous Al13 would not exist in soil solution under a high humic acid condition.
Taxonomic and Geographic Distribution of Soil Organic Carbon Pools in Ohio
Authors: Tan Zhengxi , Lal Rattan , Smeck Neil E. , Calhoun Frank G. , Slater Brian K. , Parkinson Bob , Gehring Rich M.
Published: July 2010

Spatial distribution information about soil organic C (SOC) pools at a proper scale is critical for developing feasible C sequestration programs. This study characterizes the spatial variation in SOC pools related to soil taxon, Major Land Resource Area (MLRA), and land use. Grouping data by the land uses associated with soil orders within each MLRA leads to a statewide average SOC pool of 10.2 ± 2.8 kg m−2 in the upper 1‐m depth, ranging from 7.1 kg m−2 in Ultisols to 117 in Histosols (8.8, 11.3, 12.7, and 16.9 kg m−2 in Alfisols, Inceptisols, Entisols, and Mollisols, respectively), and geographically varying from 7.7 kg m−2 in MLRA 124 to 12.0 in both MLRA 99 and 111. These variations can be also partially attributed to the properties for suborder differentiation. Moreover, land use effects are confounded by preferential selection of land for cropland use and site topographic features, resulting in a higher SOC pool in cropland (10.9 kg m−2) than in both forestland (9.5 kg m−2) and pastureland (8.4 kg m−2). The grand total SOC storage in Ohio ranges from 853 to 881 Tg (1 Tg = 1012 g). The SOC pool is primarily related to landscape slope and soil drainage, and must be considered in interpretations for C sequestration potential among land uses for each soil taxon at the MLRA scale.
Ion‐Sink Phosphorus Extraction Methods Applied on 24 Soils from the Continental USA
Authors: Myers R. G. , Sharpley A. N. , Thien S. J. , Pierzynski G. M.
Published: July 2010

Ion‐sink methods, such as resin membranes or FeO coated strips or filter papers, have been used as soil tests for plant available P. We have standardized a resin procedure and compared extractable soil P with the FeO method for 24 soils from the continental USA. Bray‐1 extractable P ranged from 0.3 to 221 mg kg−1 and Olsen's extractable P ranged from 1.4 to 131 mg kg−1 across all soils. We used anion resin membrane strips (RS) and traditional loose resin (LR) to extract soil P. Total surface area of one RS was 17.3 cm2, compared with 47.5 cm2 for one FeO‐coated filter paper. We used one, two, or three RS saturated with bicarbonate (RSbic) or chloride (RSCl), along with 1.5 g of moist LR saturated with either bicarbonate (LRBic) or chloride (LRCl). Using LRBic, the mean P was 64.3 mg kg−1 compared with 52.5 with one RSBic, 55.2 with two RSBic, and 63.9 with three RSBic Using LRCl, the mean P was 63.2 mg P kg−1 compared with 48.7 with one RSCl, 54.8 with two RSCl, and 57.3 with three RSCl The mean FeO‐P was 36.4 mg kg−1 Resin (Cl) hardly influenced pH of the extracting solution, LRBic and RSBic influenced pH most, and FeO‐strips had an intermediate effect on solution pH. This study shows that RS with a total surface area of 51.8 cm2 can be used to extract soil P in place of more time‐consuming LR methods.
Numerical Analysis of Passive Capillary Wick Samplers prior to Field Installation
Authors: Mertens Jan , Diels Jan , Feyen Jan , Vanderborght Jan
Published: July 2010

Accurately measuring water fluxes and associated nutrient or contaminant concentrations through the vadose zone is difficult because an appropriate suction needs to be exerted on the soil to sample water under unsaturated conditions. Passive capillary wick sampling systems are cheap and reliable instruments resulting in acceptable measurements of water fluxes in the vadose zone; however, their success in measuring realistic fluxes depends on their compatibility with the soil and climatic conditions in which they are installed. This study was developed in the preplanning phase of a field experiment with its main objective the monitoring of dissolved organic matter and the associated transfer of Cu2+ and pesticides through the vadose zone. We studied a combination of two‐dimensional and axisymmetrical three‐dimensional numerical analyses using the HYDRUS‐2D software to identify what sampler geometry, wick type, wick length, and number of wicks are most suitable for the soil conditions at the experimental site. An AM3/8HI wick with seasonally varying wick length (40 cm in winter and 100 cm in summer) was found to be most appropriate for the soil and climatic conditions of the experimental field. The numerical analysis indicated that well‐designed wick samplers had a negligible effect on the soil moisture content close to the sampler. A double‐ring wick sampler is proposed to minimize the effect of the area between the installation pit or trench and the sampler. This approach is easily applicable and transferable to other soil and wick types and climatic conditions. The study emphasizes the suitability of numerical modeling to optimize experimental design before installation.
A Non-Dimensional Analysis of Hemodialysis
Authors: Bonert Michael , Saville Bradley A
Published: July 2010

Background:

Non-dimensional analysis is a powerful approach that can be applied to multivariate problems to better understand their behaviour and interpret complex interactions of variables. It is has not been rigorously applied to the parameters that define renal dialysis treatments and may provide insight into the planning of hemodialysis treatments.

Methods:

Buckingham’s non-dimensional approach was applied to the parameters that define hemodialysis treatments. Non-dimensional groups were derived with knowledge of a mass transfer model and independent of it. Using a mass transfer model, the derived non-dimensional groups were plotted to develop an understanding of key relationships governing hemodialysis and toxin profiles in patients with end-stage renal disease.

Results:

Three non-dimensional groups are sufficient to describe hemodialysis, if there is no residual renal function (RRF). The non-dimensional groups found represent (1) the number of half-lives that characterize the mass transfer, (2) the toxin concentration divided by the rise in toxin concentration without dialysis for the cycle time (the inverse of the dialysis frequency), and (3) the ratio of dialysis time to the cycle time. If there is RRF, one additional non-dimensional group is needed (the ratio between cycle time and intradialytic elimination rate constant). Alternate non-dimensional groups can be derived from the four unique groups.

Conclusions:

Physical interpretation of the non-dimensional groups allows for greater insight into the parameters that determine dialysis effectiveness. This technique can be applied to any toxin and facilitates a greater understanding of dialysis treatment options. Quantitative measures of dialysis adequacy should be based on dimensional variables.
The Limits of Partisan Gerrymandering: Looking Ahead to the 2010 Congressional Redistricting Cycle
Authors: Seabrook Nicholas R
Published: July 2010

This article looks ahead to the 2010 congressional redistricting cycle, and makes the case that the concern over the pernicious effects of partisan redistricting has been significantly over-exaggerated. Those attempting to use partisan control of the apparatus of state government to influence future elections operate under a number of significant constraints, from legal and political factors that inhibit the redistricting process and frequently result in compromise or litigation, to geographical and structural factors that dictate the extent to which electoral boundaries can be effectively manipulated to produce deviations from partisan symmetry. Evidence from the 1990 and 2000 redistricting cycles indicates that the benefits of partisan gerrymandering, where present, are extremely susceptible to subsequent electoral swings. This casts considerable doubt on the utility of partisan gerrymandering as a mechanism for instituting long-term electoral bias in congressional elections.
Something Black in the American Psyche: Formal Innovation and Freudian Imagery in the Comics of Winsor McCay and Robert Crumb
Authors: Shannon Edward A.
Published: July 2010

Abstract:

Winsor McCay's Little Nemo in Slumberland anticipates Robert Crumb's work. McCay's innocent dreamscapes seem antithetical to the sexually explicit work of anti-capitalist Crumb, but Nemo looks forward to Crumb in subject and form. Nemo's presentation of class, gender, and race, and its pre-Freudian sensibility are ironic counterpoints to Crumb's political, Freudian comix.
The structure, biological activity and biogeochemistry of cryoconite aggregates upon an Arctic valley glacier: Longyearbreen, Svalbard
Authors: Hodson Andy , Cameron Karen , Bøggild Carl , Irvine-Fynn Tristram , Langford Harry , Pearce Dave , Banwart Steven
Published: July 2010

Glacier surfaces support unique microbial food webs dominated by organic and inorganic debris called ‘cryoconite’. Observations from Longyearbreen, Spitsbergen, show how these aggregate particles can develop an internal structure following the cementation of mineral grains (mostly quartz and dolomite) by filamentous microorganisms. Measurements of carbon and dissolved O2show that these microorganisms, mostly cyanobacteria, promote significant rates of photosynthesis (average 17 μgC g−1d−1) which assist aggregate growth by increasing the biomass and producing glue-like extracellular polymeric substances. The primary production takes place not only upon the surface of the aggregates but also just beneath, due to the translucence of the quartz particles. However, since total photosynthesis is matched by respiration (average 19 μgC g−1d−1), primary production does not contribute directly to cryoconite accumulation upon the glacier surface. The microorganisms therefore influence the surface albedo most by cementing dark particles and organic debris together, rather than simply growing over it. Time-lapse photographs show that cryoconite is likely to reside upon the glacier for years as a result of this aggregation. These observations therefore show that a better understanding of the relationship between supraglacial debris and ablation upon glaciers requires an appreciation of the biological processes that take place during summer.
Modelled mass balance of Xibu glacier, Tibetan Plateau: sensitivity to climate change
Authors: Caidong Caidong , Sorteberg Asgeir
Published: July 2010

Due to a lack of in situ measurements, model-based studies of glacier mass balance in the Tibetan Plateau are very limited. An energy-balance model is applied to analyse the mass-balance sensitivity of Xibu glacier, in the Nyainqêntanglha mountain range, to climatic change. A sensitivity calculation shows that a temperature change of ±1°C or a precipitation change of ±35% changes the equilibrium-line altitude (ELA) by 140 ± 125 m. We use a clustering method to link local weather parameters, including wet-season temperatures, to weather types observed over the period 1955–2006. Modelled variability of the Xibu glacier mass balance seems to be controlled by air-temperature variations during the wet season (May–September) and by a long-term warming trend that is unrelated to weather type. The observed wet-season temperature trend of 0.23°C (10 a)−1 leads to an estimated lengthening of the ablation season by 8 days at the glacier terminus (5000 m a.s.l.) and by 23 days at the ELA (5590 m a.s.l.) over the period 1966–2005. The calculated rise in the ELA was 49 m (10 a)−1.
Combinations of drugs in the Treatment of Obesity
Authors: Halpern Bruno , Oliveira Eduardo S. L. , Faria André M. , Halpern Alfredo , Melo Maria Edna de , Cercato Cintia , Mancini Marcio C.
Published: July 2010

Obesity is a chronic disease associated with excess morbidity and mortality. Clinical treatment, however, currently offers disappointing results, with very high rates of weight loss failure or weight regain cycles, and only two drugs (orlistat and sibutramine) approved for long-term use. Drugs combinations can be an option for its treatment but, although widely used in clinical practice, very few data are available in literature for its validation. Our review focuses on the rationale for their use, with advantages and disadvantages; on combinations often used, with or without studies; and on new perspectives of combinations being studied mainly by the pharmaceutical industry.
Renewable Energy Technology—Is It a Manufactured Technology or an Information Technology?
Authors: Shum Kwok L.
Published: July 2010

Socio-technical or strategic approach to renewable energy deployment all suggests that the uptake of renewable energy technology such as solar photovoltaic is as much a social issue as a technical issue. Among social issues, one most direct and immediate component is the cost of the renewable energy technology. Because renewable electricity provides no new functionality—a clean electron does the same work as a dirty electron does—but is relatively expensive compared with fossil fuel based electricity, there is currently an under-supply of renewable electricity. Policy instruments based on economics approaches are therefore developed to encourage the production and consumption of renewable electricity, aiming to remediate the market inefficiencies that stem from the failure in internalizing the environmental or social costs of fossil fuels. In this vein, the most discussed instruments are renewable portfolio standard or quota based system and the general category of feed-in tariff. Feed-in tariff is to support output or generation of the renewable electricity by subsidizing revenues. The existing discussions have all concerned about the relative effectiveness of these two instruments in terms of cost, prices and implementation efficiency. This paper attempts a different basis of evaluation of these two instruments in terms of cost and (network) externality effects. The cost effect is driven by deploying the renewable as a manufactured technology, and the network externality effect is driven by deploying the renewable as an information technology. The deployment instruments are studied in terms of how these two effects are leveraged in the deployment process. Our formulation lends itself to evolutionary policy interpretation. Future research directions associated with this new energy policy framework is then suggested.
Images as Pull Factors of a Tourist Destination: A Factor-Cluster Segmentation Analysis
Authors: Prayag Girish
Published: July 2010

Images are commonly accepted as important pull factors for the success and development of a tourist destination. Understanding how visitor characteristics influence these factors is critical for destination differentiation and positioning. In this context, the purpose of this study is to segment the international tourists' market to Cape Town on the importance level attached to various pull factors. Using a mixed methodology approach for the development of a survey instrument, 585 visitors were interviewed at various locations in Cape Town. Factor analysis showed the existence of six underlying dimensions in the data while cluster analysis demonstrated the existence of four segments. Demographics as opposed to traveling characteristics seem to define the profile of each cluster. Implications for marketing strategy formulation are provided.
Variations on a Paper of Erdős and Heilbronn
Authors: Elliott P. D. T. A.
Published: July 2010

It is shown that an old direct argument of Erdős and Heilbronn may be elaborated to yield a result of the current inverse type.
A Case When the Fiber of the Double Suspension is the Double Loops on Anick's Space
Authors: Theriault Stephen D.
Published: July 2010

The fiber Wn of the double suspension S2n–1 → Ω2S2n+1 is known to have a classifying space BWn. An important conjecture linking the EHP sequence to the homotopy theory of Moore spaces is that BWn ≃ ΩT2np+1(p), where T2np+1(p) is Anick's space. This is known if n = 1. We prove the n = p case and establish some related properties.
The effects of prayer on organizational life: A phenomenological study
Authors: Vasconcelos Anselmo Ferreira
Published: July 2010

There is substantial evidence showing that it is not uncommon for workers to face, for example, unfriendly relationships, poor organizational climate, and aggressive bosses in their work settings. While self-help readings, relaxation exercises, yoga, mentalization therapies and psychological counseling help to address workers' reactions, this paper focuses on prayer and its effects, through a phenomenological study. The results indicate that the sample members usually pray everyday and/or many times during the day. The majority of them seek for some form of celestial support, like to express gratitude to some deity, and believe that there is no right place or time to pray. The findings show that the average time that is spent on praying varies. Further, prayer is also seen as a form of communication with a divine power and it is also regarded as beneficial to deal with tasks, colleagues' relationships, negative emotions and spiritual vibrations at work settings, among other things.
Development and validation of the brief‐satisfaction with appearance scale for systemic sclerosis
Authors: Jewett Lisa R. , Hudson Marie , Haythornthwaite Jennifer A. , Heinberg Leslie , Wigley Fredrick M. , Baron Murray , Thombs Brett D. ,   The Canadian Scleroderma Research Group
Published: July 2010

Objective

Body image concerns are understudied in systemic sclerosis (SSc; scleroderma). The objective was to develop and cross‐validate a brief version of the Satisfaction with Appearance Scale (SWAP) in order to reduce item redundancy, increase SSc relevancy, and improve the feasibility of body image assessment in SSc.

Methods

Female patients with SSc in a development sample (Johns Hopkins Scleroderma Center) and a validation sample (Canadian Scleroderma Research Group Registry) completed the 14‐item SWAP. Items for the 6‐item Brief‐SWAP were selected based on theoretical considerations and psychometric data from the development sample. In both samples, internal consistency reliability, convergent validity, and the hypothesized 2‐factor structure (perceived social impact and subjective dissatisfaction) were compared between the Brief‐SWAP and SWAP.

Results

Two hundred seventeen women from the development sample and 654 women from the validation sample completed the SWAP. Cronbach's alpha for the Brief‐SWAP was 0.82 in both samples, compared with 0.90 and 0.91 for the full SWAP. Correlations between the Brief‐SWAP and SWAP were 0.94 and 0.95 in the development and validation samples, respectively. All correlations of the Brief‐SWAP and SWAP with measures of convergent validity were substantively equal with no statistically significant differences in either sample. Based on confirmatory factor analysis, model fit for the Brief‐SWAP was good in the development (χ2[4] = 9.0, comparative fit index [CFI] = 0.99, Tucker‐Lewis Index [TLI] = 0.99, root mean square error of approximation [RMSEA] = 0.07) and validation samples (χ2[4] = 19.5, CFI = 0.99, TLI = 0.99, RMSEA = 0.08) and better than for the SWAP.

Conclusion

The Brief‐SWAP is a reliable and valid measure of body image dissatisfaction and social discomfort in SSc that is shorter and more feasibly implemented than the SWAP.
Azathioprine in severe uveitis of Behçet's disease
Authors: Saadoun D. , Wechsler B. , Terrada C. , Hajage D. , Le Thi Huong D. , Resche‐Rigon M. , Cassoux N. , Le Hoang P. , Amoura Z. , Bodaghi B. , Cacoub P.
Published: July 2010

Objective

To investigate the efficacy and tolerance of azathioprine in severe uveitis related to Behçet's disease (BD).

Methods

We reported 157 consecutive patients with severe uveitis (active posterior uveitis or panuveitis) fulfilling the international criteria for BD and treated with corticosteroids (0.5–1 mg/kg/day) and azathioprine (2.5 mg/kg/day). Long‐term outcome and factors associated with complete remission were assessed.

Results

Mean ± SD age at diagnosis was 29.9 ± 10.1 years, with 71.3% men. At baseline, 59 patients (37.6%) had loss of useful vision, 54 (34.4%) had retinal vasculitis, 66 (42.0%) had panuveitis, and 132 (84.1%) had bilateral uveitis. Following azathioprine therapy, 81 patients (51.6%) were complete responders, 65 (41.4%) were partial responders, and 11 (7%) were nonresponders. The visual acuity significantly improved (P < 0.001), and a significant decrease in the mean oral prednisone dosage (55.3 to 10.5 mg/day; P < 0.001) was observed after therapy. Patients with retinal vasculitis (odds ratio [OR] 0.45 [95% confidence interval (95% CI) 0.2–0.9], P = 0.02) and severe visual loss (OR 0.28 [95% CI 0.2–0.7], P < 0.0001) at diagnosis were less likely to be complete responders. Azathioprine was well tolerated, with only 3 withdrawals due to hepatotoxic effects (n = 2) and bacterial septicemia (n = 1).

Conclusion

Azathioprine represents an effective and safe therapy in patients with severe uveitis of BD.
Syntheses and characterization of a new class of mono‐ and heterodinuclear derivatives of boron derived from Schiff bases
Authors: Sharma Priyanka , Vajpayee Vaishali , Sharma Jyoti , Singh Yashpal
Published: July 2010

Reactions of 2‐isopropoxy‐1, 3, 2‐ benzodioxaborole with equivalent amounts of Schiff base ligands having two hydroxyl groups (1a–3a) yield mononuclear derivatives with one residual hydroxy group. The reactions of these mononuclear derivatives with hexamethyldisilazane in a 2:1 ratio yield heterodinuclear derivatives. All these newly synthesized derivatives have been characterized by elemental analyses and molecular weight measurements. Tentative structures have been proposed on the basis of IR and NMR (1H, 13C, 11B,29Si)spectral data and Fab‐mass studies. Schiff bases and their corresponding mono‐ and heterodinuclear derivatives of boron have also been screened for antifungal activities. Copyright © 2010 John Wiley & Sons, Ltd.
(Z)‐1,2‐bis(ethoxydimethylsilyl)arylethenes as new building blocks for organic synthesis
Authors: Pawluc Piotr , Hreczycho Grzegorz , Szudkowska Justyna , Franczyk Adrian , Marciniec Bogdan
Published: July 2010

A new efficient synthetic protocol for highly stereoselective synthesis of (Z)‐1,2‐bis(ethoxydimethylsilyl)arylethenes from vinylsilanes based on sequential ruthenium‐catalyzed silylative coupling‐palladium‐catalyzed Heck coupling is reported. Reactivity of title compounds towards carbon electrophiles in the catalytic desilylative arylation is discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Sorption of carbon dioxide by ionic liquid‐based sorbents
Authors: Bi Wentao , Zhu Tao , Park Dong Wha , Row Kyung Ho
Published: July 2010

Ionic liquids and ionic liquid‐based materials were emerging as sorbents for carbon dioxide capture. Amino‐imidazolium materials, a kind of sorbents, were synthesized and characterized for the sorption of carbon dioxide. The ionic liquid‐modified materials have higher sorption capacity of carbon dioxide than the unmodified sorbents. The effects of pressure and temperature were investigated. The adsorbed amount of carbon dioxide increased with the increasing pressure and the ionic liquid‐based polymer show higher sorption efficiency than that of ionic liquid‐based silica. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
Microencapsulation and application of fluorine‐free water repellent agent‐AH102
Authors: Li Yonghai , Cai Zaisheng
Published: July 2010

Fluorine‐free water repellent agent, AH102, was microencapsulated by interfacial polymerization with polyurethane as shell material to restrict its hydrolysis and improve its dispersibility in water. The appearance of the resultant microcapsules was characterized with optical microscope and scanning electron microscope. Chemical structure of microcapsules was identified with Fourier‐transforming infrared spectrometer. The size and size distribution of the microcapsules were determined by laser particle size analyzer. The thermal property of the microcapsules was investigated by thermogravimetric analysis. The stability and dispersibility of the microcapsules in aqueous medium were characterized by evaluating the static water contact angles of the treated cotton fabrics with the emulsions of unencapsulated and microencapsulated AH102 at different storage intervals. The results showed that AH102 was successfully encapsulated and its stability and dispersibility in water were greatly improved. As expected, the emulsion of the microencapsulated AH102 became more stable than that of the unencapsulated one at water repellence to cotton fabric with increasing storage intervals. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of oxidized polypropylene as a new compatibilizer on the water absorption and mechanical properties of wood flour–polypropylene composites
Authors: Najafi Saeed Kazemi , Bahra Alireza , Abdouss Majid
Published: July 2010

The effect of oxidized polypropylene (OPP) as new compatibilizer on the water absorption and mechanical properties of wood flour–polypropylene (PP) composites were studied and compared with maleic anhydride grafted polypropylene (MAPP). The oxidation of PP was performed in the molten state in the presence of air. Wood flour, PP, and the compatibilizers (OPP and MAPP) were mixed in an internal mixer at temperature of 190°C. The amorphous composites removed from the mixer were then pressed into plates that had a nominal thickness of 2 mm and nominal dimensions of 15 × 15 cm2 with a laboratory hydraulic hot press at 190°C. Physical and mechanical tests showed that the wood flour–PP composites with OPP exhibited higher flexural and impact properties but lower water absorption than MAPP. All of the composites with 2% compatibilizers (OPP and MAPP) gave higher flexural and impact properties and lower water absorption compared to those with 4% compatibilizers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Thermal and mechanical properties of wood flour–polystyrene blends from postconsumer plastic waste
Authors: Lisperguer Justo , Bustos Ximena , Saravia Yanina
Published: July 2010

Polystyrene (PS) from packing materials and plastic cups was reinforced with 30 and 50% wood flour through a blending process with and without a commercial compatibilizing agent. The processability of the pure recycled polystyrene (rPS) and wood–rPS composites was studied in terms of the torque of the mixing process; this was then compared with that of a commercial virgin multipurpose PS. The physical and mechanical properties were compared with those of the virgin PS reinforced with 30 and 50% wood flour. The results show that the mechanical properties of the pure and reinforced rPS did not decrease with respect to the virgin PS, and in terms of the impact strength, the rPS was superior to the virgin plastic. The mechanical properties were not affected by the commercial compatibilizing agent, but the torque of the blends was significantly lower with the compatibilizer. Differential scanning calorimetry (DSC) and dynamic mechanical analysis were used to study the glass‐transition temperature (Tg) of both the pure virgin PS and pure rPS and the wood flour–PS composites. The Tg values of the rPS and wood–rPS composites were higher than those of the virgin PS and wood–virgin PS composites. The use of rPS increased the stiffness and flexural modulus of the composites. Thermogravimetric analysis revealed that the thermal stability of rPS and its composites was slightly greater than that of the virgin PS and its composites. These results suggest that postconsumer PS can be used to obtain composite materials with good mechanical and thermal properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Styrene/phosphonic acid copolymers: Synthesis and thermal, mechanical, and electrochemical characterization
Authors: Santos L. E. P. , Hanamoto L. S. , Pereira R. P. , Rocco A. M. , Felisberti M. I.
Published: July 2010

In this study, a series of poly(styrene‐co‐vinyl phosphonic acid) [P(S‐co‐VPA)] copolymers were synthesized by the free‐radical copolymerization of styrene and vinyl dimethyl phosphonate followed by alkaline hydrolysis. The P(S‐co‐VPA) copolymers were characterized by size exclusion chromatography (gel permeation chromatography), Fourier transform infrared vibrational spectroscopy, proton nuclear magnetic resonance, thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, and electrochemical impedance spectroscopy. Despite the difference between the copolymerization ratios of styrene and vinyl dimethyl phosphonate, the resulting copolymers presented single glass transitions at temperatures that depended on the acidic group amount. The glass transition shifted to a higher temperature and became broader as the amount of phosphonic acid increased. The storage modulus at temperatures higher than the glass transition also increased with increasing acidic groups because of intramolecular and intermolecular interactions. All of the acid copolymers were thermally stable to at least 300°C. A high oxidative stability was found for 3 : 1 P(S‐co‐VPA), which also presented conductivity values on the order of 10−6 Ω−1 cm−1 at room temperature. The 1 : 1 P(S‐co‐VPA) membrane presented Arrhenius‐type behavior at temperatures from 30 to 80°C and conductivity on the order of 10−5 Ω−1 cm−1. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Aliphatic polyurethane–montmorillonite nanocomposite coatings: Preparation, characterization, and anticorrosive properties
Authors: Ashhari Shabnam , Sarabi Ali Asghar , Kasiriha Seyed Mahmoud , Zaarei Davood
Published: July 2010

Polyurethane (PU)–clay nanocomposite coatings were prepared by a sonication method. The stability and morphology of these coatings was characterized by turbidometry, X‐ray diffraction, and transmission electron microscopy. The anticorrosive properties of these coatings were investigated by salt‐spray and electrochemical impedance spectroscopy methods. According to the results, dispersed nanoclay layers in the matrix of the nanocomposite coating compositions led to superior anticorrosive characteristics compared to those of pure PU coatings. The best results were obtained with coatings containing about 5 wt % clay. The resistance of the coating containing 5% clay was about 9.002 GΩ after 225 days of immersion in a 3.5 wt % NaCl solution, whereas it was only 97 kΩ for the pure PU coating. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
A three‐function numerical model for the prediction of vulcanization‐reversion of rubber during sulfur curing
Authors: Milani G. , Milani F.
Published: July 2010

The cross‐linking mechanisms of sulfur vulcanization are not analytically known and, therefore, reticulation kinetics has to be deduced macroscopically from standardized tests. One of the most popular laboratory test to characterize curing and reversion is the oscillating disk rheometer ODR, which gives a quantitative assessment of scorch, cure rate, and state of cure. In this article, a numerical two‐step approach, which is based on the utilization of experimental ODR data and aimed at predicting the degree of vulcanization of thick rubber items cured with accelerated sulfur, is presented. In step one, a composite numerical three‐function curve is used to fit experimental rheometer data, able to describe the increases of the viscosity at successive curing times and at different controlled temperatures, requiring only few points of the experimental cure curve to predict the global behavior. Both the case of indefinite increase of the torque and reversion can be reproduced with the model. In step two, considering the same rubber compound of step one, numerical cure curves at different temperatures are collected in a database and successively implemented in a Finite Element software, which is specifically developed to perform thermal analyzes on complex 2D/3D geometries. As an example, an extruded thick EPDM section is considered and meshed through eight‐noded isoparametric plane elements. Several FEM simulations are repeated by changing exposition time tc and external curing temperature Tn, to evaluate for each (tc,Tn) couple the corresponding mechanical properties of the item at the end of the thermal treatment. A recently presented bisectional approach, alternating tangent (AT), is used to drastically reduce the computational efforts required to converge to the optimal solution associated with the maximum value of an output property, tensile strength. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Removal of phosphate by using copper‐loaded poly(N‐vinylimidazole) hydrogels as polymeric ligand exchanger
Authors: Özmen Fulya , Kavaklı Pınar Akkaş , Güven Olgun
Published: July 2010

Polymeric ligand exchangers (PLE) are generally composed of a crosslinked hosting resin that can firmly hold a transition metal ion which can act as terminal functional groups. In this study, poly(N‐vinylimidazole) (PVIm) hydrogels were synthesized by free radical polymerization/crosslinking of N‐vinylimidazole in aqueous solution. Swelling behavior of PVIm hydrogels was investigated and the gel with minimum amount of crosslinking agent, hence showing maximum swelling was selected as the optimum gel system for further studies. To prepare the corresponding PLE for the removal of phosphate, PVIm hydrogels were loaded with Cu(II) ions. Copper loading capacity of PLE was determined to be 5 mmol of Cu(II)/g of dry gel. For removal of phosphate, adsorption experiments were performed in batch mode at different pH (3–9) and phosphate concentrations. It was found that phosphate adsorption capacity did not change significantly within this pH range. The effect of initial concentration of phosphate on the adsorption behavior of PLE was determined for 10 different phosphate concentrations (0.1–1000 mg/L) at pH 7. NaCl solution was used for regeneration of phosphate adsorbed Cu(II) loaded PVIm hydrogels with 100% regeneration efficiency. The new PLE showed high affinity for phosphate; the highest uptake was found to be 218 mg/g dry PLE from 1000 mg/L phosphate solution. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Metabolomic profiling can differentiate between bactericidal effects of free and polymer bound halogen
Authors: Ahmed Abd El‐Shafey I. , Wardell John N. , Thumser Alfred E. , Avignone‐Rossa Claudio A. , Cavalli Gabriel , Hay John N. , Bushell Michael E.
Published: July 2010

The effects of two halogenated compounds (sodium hypochlorite and N‐halamine polymers) on the Escherichia coli metabolome were investigated. Changes in the intracellular metabolite pools of bacterial cells treated with different formulations of these compounds were analysed using FTIR (Fourier Transform Infra Red) spectroscopy and LC‐MS (Liquid Chromatography‐Mass Spectroscopy). Principal component analysis was used to generate metabolic profiles of the intracellular metabolites to investigate the effect of sublethal concentrations on the metabolome of treated cells. The effect of treatment with sodium hypochlorite was quantitatively dependent on the exposure time. The resulting metabolic profiles supported our previous hypothesis that the mode of action of some halogenated compounds, such as N‐halamine polymers, can be initiated by release of halogen ions into the aqueous environment, in addition to direct contact between the solid polymer material and the bacterial cells. Moreover, the metabolic profiles were able to differentiate between the effect of free and polymer‐bound halogen. Our metabolomic approach was used for hypothesis generation to distinguish apparently different bactericidal effects of free and polymer‐bound halogen. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Characterization, mechanical, and thermal properties of gamma irradiated starch films reinforced with mineral clay
Authors: Ibrahim Sayeda M.
Published: July 2010

Composite fabricated from starch and different concentrations of clay was prepared by solution casting method. The casted film was irradiated to different gamma irradiation doses 10, 20, 30, and 40 kGy. The dispersion of clay into starch was investigated by using X‐ray diffraction (XRD). The structural morphology of the composite was measured by scanning electron microscope and infrared spectroscopy. Film properties, such as water vapor transmission, mechanical, and thermal properties were also measured. The gel content and swelling behavior of the starch/clay composite were investigated. It was found that the gel content increases with increasing clay content and irradiation dose. The results obtained indicate that the starch/clay composite showed an increase in the tensile strength, thermal stability. Moreover, there is a decrease in water vapor transmission (WVRT) which improves its barrier properties. Both XRD and infrared spectroscopy showed that starch can be intercalated into the clay galleries. Also antibiotic drug Chlortetracycline HCl was loaded into the starch/clay composite by direct adsorption method. Chlortetracycline HCl adsorption capacity of composite was found to increase from 1.13 to 4.20 mg Chlortetracycline HCl per gram dry film with increasing amount of drug concentration. In vitro drug release studies in different buffer solutions showed that the basic parameters affecting the drug release behavior of the film are pH of the solution, drug concentration, and time. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Adsorption behavior of monomers and formation of conducting polymers on polyester fibers
Authors: Zhao Yaping , Cai Zaisheng , Zhou Zhaoyi , Fu Xiaolan
Published: July 2010

In situ adsorption of monomers on fibers plays a key role in fabricating highly conductive polyaniline (PANI)‐based textiles by two‐stage oxidation polymerization. Experiments were conducted in aniline monomer and hydrochloric acid solution with the variables such as contact time, initial concentration, and temperature, which can enhance the equilibrium adsorption capacity to aniline of poly(ethylene terephthalate) (PET) fibers. Equilibrium data were fit well by a Henry partition‐type isotherm equation. It was found that the kinetics of the adsorption of aniline onto PET fibers at different operating conditions was best described by the pseudo‐second‐order model. The rate parameters of the intraparticle diffusion model for adsorption were also evaluated and compared to identify the adsorption mechanisms. The monomer exhaustion increased with increasing the temperature. The value of electrical surface resistance of conductive textiles about 3.2 kΩ was obtained when the padder squeeze step was introduced, and the molar ratio of 0.6 between the oxidant concentration and the exhausted concentration of monomers at the adsorption equilibrium was applied. Scanning electron micrographs of PANI/PET composite surfaces were observed, conforming that smooth films were produced by surface polymerization of aniline monomers adsorbed previously on fibers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011