bluuebunny/crossref_metadata_2025 huggingface dataset:
Impacts of temperature on performance in two species of South African dwarf chameleons,Bradypodion pumilumandB. occidentale
Authors: Segall Marion A. , Tolley Krystal A. , Vanhooydonck Bieke , Measey John G. , Herrel Anthony
Published: July 2013

Temperature is an extrinsic factor which influences reptile behavior given that their physiology is dependent on environmental temperature. Understanding the impact of temperature on performance traits is important as it may affect the ecology and fitness of ectothermic animals such as reptiles. Here we examine the temperature dependence of performance in two species of South African Dwarf chameleon (Bradypodion), a semi-arid and a mesic adapted species. Ecologically relevant performance traits were tested at different temperatures to evaluate their thermal dependence and temperature-performance breadths for 80% and 90% of each performance trait were calculated. Our results show distinct differences in the thermal dependence of speed versus force-related performance traits. Moreover, our results show that the semi-arid species is better adapted to higher temperatures and as such has better chances to cope with the predicted increases in temperature. The mesic-adapted species seems to be more sensitive to an increase in temperature and could therefore potentially be threatened by predicted future climate change. However, further studies investigating the potential for acclimation in chameleons are needed to better understand how animals may respond to predicted future climate change.
A New Family of Multiple-Bond Compounds between Heavier Group 14 Elements
Authors: Sasamori Takahiro , Tokitoh Norihiro
Published: July 2013

On the basis of fundamental research on the chemistry of π-electron systems between heavier main group elements, it was found that such π-electron systems should exhibit higher HOMO and lower LUMO as compared with those between second row elements. That is, the π-electron systems between heavier main group elements are possibly good electron acceptors, good electron donors, and good electron transporters. From the viewpoint of creation of novel π-electron systems and fundamental research on such π-electron system of heavier main group elements, a novel type of doubly and triply bonded compounds between heavier group 14 elements was successfully synthesized by taking advantage of kinetic stabilization using bulky substituents. The new family of multiple-bond compounds obtained here are (i) 1,2-dibromodimetallenes, Ar(Br)E=E(Br)Ar (E = Si, Ge, Ar = bulky aryl group), as a possible building block of a π-bond between heavier group 14 elements, (ii) 1,2-diaryldimetallynes (ArE≡EAr, E = Si, Ge) as a unique and reactive π-bonding, and (iii) 1,2-dihydrodisilenes, Ar(H)Si=Si(H)Ar, as a simple disilene. The fundamental physical and chemical properties of the newly obtained compounds have been revealed, showing that such π-electron systems between heavier group 14 elements should be completely different from those of carbon systems and should be of great interest as unique π-systems. Thus, the compounds obtained here are not only “stable multiple bonds” but also possible candidates for novel material species.
Practical and Scalable Syntheses of Substituted Ketene Dithioacetal Monoxides
Authors: Murakami Kei , Yorimitsu Hideki , Osuka Atsuhiro
Published: July 2013

Practical syntheses of substituted ketene dithioacetal monoxides (KDMs) from the corresponding aldehydes or ethyl trifluoroacetate are described. Newly developed procedures are scalable and versatile to provide aryl-, alkyl-, and trifluoromethyl-substituted KDMs in gram scales.
Synthesis of Methyl epi-Anhydroquinate Utilizing [2,3]-Sigmatropic Rearrangement of Iodosoalkene
Authors: Inomata Sho , Ueda Minoru , Sugai Takeshi , Shoji Mitsuru
Published: July 2013

Sigmatropic rearrangement has been utilized for stereoselective syntheses of structurally complicated natural products because of its high stereoselectivity and reactivity. Quinic acid (1) and its epimer 2 are versatile building blocks for the preparation of various bioactive compounds. We report the synthesis of methyl epi-anhydroquinate 3 via the [2,3]-sigmatropic rearrangement of iodosoalkene.
Treatment of Landfill Leachate by Microwave-Fenton Oxidation Process Catalyzed by Fe2+ Loaded on GAC
Authors: Ding Zhan , Guan Weisheng
Published: July 2013

Landfill leachate is one kind of the most harmful types of high-concentration organic waste water. The effective processing method is necessary to improve the treating efficiency of landfill leachate. In this study, the microwave-Fenton oxidation process was conducted to treat aged landfill leachate with the catalytic effect of Fe2+ loaded on granular activated carbon (GAC). The removal ratios of chemical oxygen demand (COD) and NH3-N were adopted as the indexes to analyze the influence of several factors, like the amount of loading Fe2+, the GAC dosage, the microwave irradiation time, the microwave power, the H2O2 dosage, and the pH value of the water sample on the efficiency of the Fenton reagent oxidation to landfill leachate. The corresponding microanalysis and kinetics were also performed. The results indicate that microwave energy can enhance the Fenton oxidation reaction and promote colloidal flocculation in the leachate. The removal ratio of COD is mainly because of oxidation, whereas that of NH3-N is mainly because of the flocculation and adsorption. Under the optimal conditions, loading Fe2+ amount = 33.32 mg/g, GAC dosage = 10 g/l, microwave power = 720 W, microwave irradiation time = 30 min, H2O2 (concentration of 30 %) dosage = 0.10 mol/l, and initial pH value = 3, the maximum remova1 ratios of COD and NH3-N are, respectively, up to 93.01 % and 85.76 %. The characteristic peaks of the organic pollutants in treated landfill leachate disappear or significantly weaken, which means that the proposed process is effective. In addition, according to the experiment results, a kinetics model of microwave-Fenton oxidation reaction is established preliminarily.
A Re-Look at the Asphalt Mixture Performance Test Protocols and Computational Algorithms
Authors: Roy Neethu , Veeraragavan A. , Jain P. K. , Krishnan J. Murali
Published: July 2013

Asphalt mixture performance tests (AMPTs) are developed to complement the Superpave volumetric mix design procedure and to reliably measure the mechanical response characteristics of the asphalt mixtures. The AMPT protocols, such as dynamic modulus, flow time and flow number test protocols, and the computational algorithms for post-processing of data are in the development stages and require further refinement. In this investigation, AMPTs were carried out on asphalt mixtures with unmodified, polymer-modified, and crumb-rubber-modified binders. Dynamic modulus test was carried out for a wide range of temperatures and frequencies and master curves were constructed. It was observed that the American Association of State Highway and Transportation Officials (AASHTO) procedure for master curves does not take into account the influence of phase angle, and this could hinder the effective use of this input in pavement design and analysis. Flow time and flow number tests were carried out for an extended time of 100 000 s (cycles) rather than the currently practised 10 000 s (cycles) protocol. The test data was used in assessing the various algorithms for evaluating flow values. A wheel tracking test was also carried out and it was found that the response of mixtures could be correlated to wheel tracking test results in a qualitative manner to the flow time test.
Stress State of GaN Epilayer Grown on Sapphire and 6H-SiC Substrates
Authors: Zhang Kexiong , Liang Hongwei , Song Shiwei , Yang Dechao , Shen Rensheng , Liu Yang , Xia Xiaochuan , Luo Yingmin , Du Guotong
Published: July 2013

The stress states and influence of two opposite stress types under similar stress intensities on the structural and optical properties of GaN films grown on sapphire and 6H-SiC substrates via metalorganic chemical vapor deposition were investigated. The E2 (high) phonon shifts of Raman spectra show that tensile stresses exist in the GaN epilayer grown on 6H-SiC, whereas compressive stresses appear in the film grown on sapphire, indicating that the thermal mismatch between the epilayers and the substrates plays a major role in determining the residual stresses in GaN films. Narrower full widths at half-maximum of E2 (high) phonon and double crystal X-ray diffraction peaks and the higher E2 (high) phonon intensity are visible for the GaN film grown on sapphire, illustrating that under almost equivalent stress intensities, tensile stresses have a much more negative influence on the crystalline quality of GaN epilayers. Finally, a numerical relationship between the luminescent band gap and the biaxial stresses of the GaN films is obtained at 10 K.
Centrifuge Model Test Study of Static and Cyclic Behavior of a Pile Foundation for an Offshore Wind Generator
Authors: Zhang Ga , Rong Bing , Fu Ping
Published: July 2013

The use of large-diameter piles as foundations for offshore wind-driven generators has become increasingly common in recent years. These piles are usually located in saturated soft clay and experience a wide variety of static and dynamic loads. A new approach was described to simulate different types of loads on a large-diameter pile under high g levels in centrifuge model tests by simplifying the complex horizontal load combinations to which such a pile is typically subjected. A series of centrifuge model tests was conducted to assess the influence of several factors. An image-based measurement system, together with a transducer-based measurement, was used to obtain a comprehensive understanding of the response of the soil. The horizontal load-induced bending moment of the pile exhibited a nearly triangular distribution. A critical load, which can be estimated as approximately half of the ultimate load, was found to exist, beyond which the rate of displacement of the pile increased significantly with increasing load. The pile-induced deformation of the soil, concentrated within zones on both sides of the pile, gradually increased as the load increased and became nearly constant when the load was close to the ultimate load. Significant separation occurred between the pile and the neighboring soil in the upper part of the pile. The critical and ultimate loads of the pile were significantly dependent on the behavior of the soil in the upper layer, the depth, and the diameter of the pile.
Method for Dynamic Material Property Characterization of Soft-Tissue-Mimicking Isotropic Viscoelastic Materials Using Fractional Damping Models
Authors: Martin Bryn A. , Kutluay Umit , Yazicioglu Yigit
Published: July 2013

Characterization of the mechanical properties of human-tissue-mimicking silicone elastomers is important for producing accurate tissue models for experimentation. However, the viscoelastic and frequency-dependent material properties of elastomers are difficult to quantify. We present a material characterization technique for a silicone elastomer used to mimic human soft tissue based on generalized-Maxwell-type material models with and without fractional dissipating mechanisms. The silicone specimens were prestressed and had the shape of cylindrical rods. It was possible to consistently identify material properties of all specimen samples from different batches of the material obtained from the manufacturer. As a general trend, material models with a higher number of parameters performed better, with the exception of models with fractional order damping mechanisms. Fractional models had the highest success for nearly all the samples in representing the dynamic behavior of the elastomer in the frequency range of 5–100 Hz, where the specimen structure displays a strong modal response.
Comparator With Optical Encoder System for the Calibration of Leveling Staffs
Authors: Marjetič Aleš , Kogoj Dušan
Published: July 2013

Geometric leveling is the most precise and universal method used to determine heights. In order to achieve the greatest possible accuracy, the method demands a calibrated leveling staff, which requires an appropriate calibration facility. The encoded shape of the leveling staff demands the rebuilding of comparators designed for calibrating classical leveling staffs. The comparator MSGL001 at the Faculty of Civil and Geodetic Engineering in Ljubljana is based on an optical encoder system that is an original solution of snapshot positioning. The aim of this paper is to present the rebuilt comparator and the details of its testing.
A Numerical Study on Effective Modulus of Elasticity in Crack Length Evaluation for Single-Edge Bending Specimens
Authors: Wang Enyang , Zhou Wenxing , Shen Guowu
Published: July 2013

The actual state of stress in the remaining ligament of a single-edge bending (SE(B)) specimen, which is neither plane stress nor plane strain, is critical in accurately predicting the crack length in the specimen involved in the unloading compliance method. Three-dimensional finite element analyses were carried out in this study to evaluate the effective modulus of elasticity that reflects the actual state of stress corresponding to the crack mouth opening displacement (CMOD) compliance of the SE(B) specimen. Both plane-sided and side-grooved specimens with a wide range of geometric configurations and crack lengths were included in the study. A practical approach is further proposed to quickly evaluate the effective modulus from the CMOD compliance determined based on the test data. The proposed approach was verified using experimental data and numerical analysis results. The results of the verification suggest that replacing the elastic modulus corresponding to the plane stress or plane strain condition with the effective modulus in commonly used a/W–CMOD compliance equations can markedly improve the accuracy of the predicted crack length.
Decision Procedure for the Weibull Distribution Based on Run Lengths of Conforming Items
Authors: Aslam Muhammad , Nezhad Mohammad Saber Fallah , Azam Muhammad
Published: July 2013

In this study, acceptance sampling has been developed using the run lengths of conforming items for Weibull-distributed products. The plan parameters of the proposed plan were determined such that the given risks were satisfied for specified values of the mean ratio, shape parameter, and experiment time. Formulas for gamma distribution are also suggested in this paper. A comparison of the proposed plan with the existing repetitive group sampling plan was made, and the proposed plan was found to perform better than the existing sampling plan. Tables are provided for the selection of the plan parameters for inspection purposes. A real example is used to describe the plan developed here.
Optimization of Vickers Hardness Parameters for Micro- And Macro-Indentation of Grade 91 Steel
Authors: Siefert J. A. , Shingledecker J. P. , Parker J. D.
Published: July 2013

Hardness is being assessed as a potential life-assessment tool for tracking microstructural degradation and remaining life in creep strength enhanced ferritic (CSEF) steels. Such methodology is already being utilized for the CSEF steel Grade 91, which has been widely implemented in both replacement parts and new construction over the last two decades. Additionally, research into the complex microstructural features in welded joints often utilizes hardness surveys to characterize changes caused by thermal processing. New automated hardness testing equipment now affords the ability to develop statistically relevant datasets for these uses. However, proper application and understanding of the data requires knowledge of limitations and variations with the load and spacing of the hardness indents and the potential role of different material conditions in this complex steel. In this work, we have examined the effect of load in three Grade 91 material conditions, as well as the effect of spacing in as-received material to determine optimum parameters for both macrohardness (i.e., >1 kg) and microhardness mapping (i.e., <500 g). The results show that to minimize variations in microhardness and ensure consistency with macrohardness results, a 200 -g load is preferred for characterization. Laser scanning microscopy was utilized to clarify the potential for indentation size effects (ISE).
A Method to Obtain Straight Crack Fronts During Pre-Cracking of Compact Tension Specimens
Authors: Öberg Martin
Published: July 2013

A common problem during pre-cracking of compact tension (CT) specimens is skewed crack fronts. It is also one of the most common reasons for which tests according to, for instance, ASTM E1820-11: Standard Test Method for Measurement of Fracture Toughness, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA, 2012, do not give valid results. This problem is normally a result of the fact that specimens and fixtures are not perfectly aligned, even when the testing setup meets the requirements of ASTM standards. In the present investigation, aluminum bushings have been used to rearrange the loads transferred from the testing machine to the specimens. Geometrical errors were deliberately introduced to the testing setup so that the specimens were asymmetrically loaded. The introduced errors were, however, within the tolerances of ASTM standards. Steel specimens with two different notch types, Chevron and straight notches, were tested, both with and without aluminum bushings. The specimens were pre-fatigued and thereafter broken under monotonic loading. The specimen crack lengths were measured and validated according to ASTM E1820-11. The results related to pre-fatigued specimens with aluminum bushings were shown to be valid, whereas the results for specimens without bushings did not meet the ASTM standards requirements.
Direct Shear Testing Performed on Multi-Component GCLs With Laminated/Coated Side
Authors: Youngblood Jimmy , Kline J. P.
Published: July 2013

Interface shear strength is a critical property used by engineers to evaluate the appropriateness of products for their specific applications. Internal shear strength is another critical property for composite products such as geosynthetic clay liners (GCLs) where the product can shear internally before the interface shear strength is mobilized. Multi-component GCLs are a newer type of GCL consisting of either a polymeric membrane liner laminated to or a membrane coating applied to one of the geotextile carriers. Direct shear testing was performed on multi-component GCLs to assess the internal shear strengths of the coatings and laminates on the geotextile surface of the GCL. Direct shear testing was performed on multiple coated and laminated GCLs. Fine-grained sand was used as the interface against the GCL to simulate typical field conditions for these products. The testing was performed in accordance with typical parameters from ASTM D6243-09 using two different loading conditions. The direct shear testing protocol, test results, and observations from the tests performed are discussed.
Water-Vapor Diffusion Through Polymeric Barriers Used in Multi-Component GCLs
Authors: Allen S.
Published: July 2013

The use of geomembranes as components in multi-component geosynthetic clay liners (GCLs) has emphasized the important difference between traditional geotechnical hydraulic conductivity testing associated with porous materials including bentonites, and water-vapor transmission testing associated with intact geomembranes. This paper will review the differences and testing features associated with each type of analysis. Available standards for relevant tests will be reviewed. Finally, results of ASTM E96-10, and ASTM F1249-11 tests will be provided for two thin geomembranes used in composite GCLs.
Medullary thyroid carcinoma and duodenal calcitonin-secreting neuroendocrine tumour: more than coincidence?
Authors: Huguet I , Lamas C , Vera R , Lomas A , Quilez R P , Grossman A , Botella F
Published: July 2013

Neuroendocrine tumours (NETs) are a heterogeneous group of neoplasms whose management can be problematic. In many cases, multiple tumours may occur in the same patient or his or her family, and some of these have now been defined genetically, although in other cases the underlying gene or genes involved remain unclear. We describe a patient, a 63-year-old female, who was diagnosed with a medullary thyroid carcinoma (MTC), which was confirmed pathologically after thyroidectomy, but whose circulating calcitonin levels remained elevated after thyroidectomy with no evidence of metastatic disease. Subsequently, an entirely separate and discrete duodenal NET was identified; this was 2.8 cm in diameter and was removed at partial duodenectomy. The tumour stained immunohistochemically for calcitonin, and its removal led to persistent normalisation of the circulating calcitonin levels. There was no germline mutation of the RET oncogene. This is the first identification of a duodenal NET secreting calcitonin and also the first demonstration of a second tumour secreting calcitonin in a patient with MTC. We suggest that where calcitonin levels remain high after removal of a MTC a search for other NETs should be conducted.

Learning points

NETs are a complex and heterogeneous group of related neoplasms, and multiple tumours may occur in the same patient.

Calcitonin can be produced ectopically by several tumours outside the thyroid.

Persistently elevated calcitonin levels after removal of a MTC may not necessarily indicate persisting or metastatic disease from the tumour.

The real prevalence of calcitonin-producing NETs may be underestimated, as serum determination is only recommended in the diagnosis of pancreatic NETs.
Precast alkali-activated concrete towards sustainable construction
Authors: Brandão Ferreira Luís Filipe , Sousa Costa Hugo Sérgio , Antunes Barata Inês Isabel , Júlio Eduardo Nuno Brito Santos , Tiago Paulo Maranha Nunes , Coelho Jorge Fernando Jordão
Published: July 2013

Currently, the development of durable eco-efficient materials is a priority for the construction sector. In this regard, the alkaline activation of fly ash is a promising solution: it allows ordinary Portland cement (OPC), responsible for 5% of carbon dioxide emissions worldwide, to be replaced by an industrial by-product. Moreover, the resulting alkali-activated concrete (AAC) also presents an advantage, compared to OPC-based concrete, in terms of enhanced durability. The project herein described combines the huge advantage of AAC for the sustainability of the construction sector with the intrinsic characteristics of AAC that make it most suitable for the precast industry. The prefabrication of AAC façade panels was defined as the main goal, which makes this project one of the very few studies that refer to the production and the structural behaviour of AAC elements of considerable size. The following objectives were defined: (a) to study the properties of the AAC; (b) to develop the industrial production process of the AAC panels, including heat curing; and (c) to study the structural behaviour of the panels.
Long‐lived organisms provide an integrative footprint of agricultural land use
Authors: Atkinson Carla L. , Christian Alan D. , Spooner Daniel E. , Vaughn Caryn C.
Published: July 2013

Nitrogen (N) fertilizer runoff into rivers is linked to nutrient enrichment, hydrologic alteration, habitat degradation and loss, and declines in biotic integrity in streams. Nitrogen runoff from agriculture is expected to increase with population growth, so tracking these sources is vital to enhancing biomonitoring and management actions. Unionid mussels are large, long‐lived, sedentary, primary consumers that transfer particulate material and nutrients from the water column to the sediments through their filter feeding. Because of these traits, mussels may provide a temporal integration of nitrogen inputs into watersheds. Our goals were to (1) establish a baseline δ15N signature for unionid mussels in watersheds not heavily influenced by agriculture for use in comparative analyses and (2) determine if mussels provide an integrative measure of N sources in watersheds with varying percentages of agriculture across large spatial scales. We compiled tissue δ15N data for 20 species of mussels from seven geographic areas, including 23 watersheds and 42 sample sites that spanned varying degrees of agricultural intensification across the eastern United States and Canada. We used GIS to determine land cover within the study basins, and we estimated net anthropogenic nitrogen inputs (NANI) entering these systems. We then determined the relationship between mussel tissue δ15N and percentage of land in agriculture (%AG) and net anthropogenic N loading. The δ15N of mussel tissue could be predicted from both %AG and net anthropogenic N loading, and one component of NANI, the amount of N fertilizer applied, was strongly related to the δ15N of mussel tissue. Based on our results, mussels occupying a system not affected by agricultural land use would have a baseline δ15N signature of approximately 2.0‰, whereas mussels in basins with heavy agriculture had δ15N signatures of 13.6‰. Our results demonstrate that mussels integrate anthropogenic N input into rivers at a watershed scale and could be a good bioassessment tool for tracking agriculture N sources.
Unexpected redwood mortality from synergies between wildfire and an emerging infectious disease
Authors: Metz Margaret R. , Varner J. Morgan , Frangioso Kerri M. , Meentemeyer Ross K. , Rizzo David M.
Published: July 2013

An under‐examined component of global change is the alteration of disturbance regimes due to warming climates, continued species invasions, and accelerated land‐use change. These drivers of global change are themselves novel ecosystem disturbances that may interact with historically occurring disturbances in complex ways. Here we use the natural experiment presented by wildfires in redwood forests impacted by an emerging infectious disease to demonstrate unexpected synergies of novel disturbance interactions. The dominant tree, coast redwood (fire resistant without negative disease impacts), experienced unexpected synergistic increases in mortality when fire and disease co‐occurred. The increased mortality risk, more than fourfold at the peak of the effect, was not predictable from impacts of either disturbance alone. Changes in fire behavior associated with changes to forest fuels that occurred through disease progression overwhelmed redwood's usual resilience to wildfire. Our results demonstrate the potential for interacting disturbances to initiate novel successional trajectories and compromise ecosystem resilience.
Application of Operator-Splitting Technique in Numerical Simulation of Gas-Hydrate Reservoirs
Authors: Shahbazi A.. , Pooladi-Darvish M..
Published: July 2013

Modeling of hydrate reservoirs has revealed large time-scale discrepancies between the mechanisms involved. Compared with the fluid- and heat-flow terms, the time scale of the kinetics term is orders of magnitude smaller, especially when the intrinsic reaction rate is large. Previous studies have shown that simulation of hydrates may require very small timesteps to ensure convergence. Further investigations have shown that, for sharp decomposition cases in which dissociation occurs in a narrow region, nonphysical oscillation becomes a simulation issue, unless very small time-steps are chosen. A 3D numerical model incorporating heat and fluid flow with kinetics of decomposition and reformation of hydrates has been developed. In this paper, a methodology for the use of larger timesteps is proposed without loss of accuracy. The focus of this work is on the decoupling of the reaction and flow operators. The decoupling, or so-called operator splitting, allows selection of different timesteps for the different mechanisms. The success of the splitting methodology in saving computational time is demonstrated for two cases. The first case shows oscillatory solutions, and the application of operator splitting allows for an oscillation-free solution at a smaller run time. In the second case, a problem with a range of reaction constants is studied. Obtaining a stable solution without operator splitting requires adjusting the overall timestep, such that the problem with the faster reaction requires very small timesteps. The application of operator splitting in this case allows for a stable solution with much larger timesteps. The contribution of this work is developing a methodology to improve the computational-time of large-scale simulations of gas-hydrate reservoirs without loss of accuracy.
Long‐Term Manure Applications Impact on Irrigated Barley Forage Mineral Concentrations
Authors: Benke Mônica B. , Indraratne Srimathie P. , Hao Xiying
Published: July 2013

Long‐term manure use near livestock feedlot operations can result in soil nutrient imbalances. We investigated the impact of continuous (37‐yr) and discontinued (30‐yr continuous + 7 yr without applications) manure applications on soil properties and barley (Hordeum vulgare L.) yield and nutritive value under semiarid field conditions in southern Alberta, Canada. Feedlot cattle manure annual applications were 0, 60, 120, and 180 Mg ha–1 (wet weight) to an irrigated Chernozemic soil. After 37 yr, barley yields were not affected by manure applications, while forage crude protein (CP), NO3–N, P, K, and Zn concentrations increased (P < 0.01). Forage Ca/P ratios decreased and K/(Ca + Mg) ratios increased with manure applications to critical levels of illness potential in ruminants. Discontinuing manure applications did not affect forage CP content; however, forage P and K concentrations declined (P < 0.01) with decreases in soil P and K. This resulted in the return of forage Ca/P ratios within the recommended levels. Seven years after manure applications were discontinued, forage Zn concentrations were similar to concentrations from unmanured plots. Although forage nutrient balances for animal nutrition improved after manure applications were discontinued, soil nutrient recovery was small, and soil P, K, and Zn concentrations in the discontinued plots remained greater (P < 0.01) than concentrations in the unmanured plots and well above those required for optimum crop growth.
Phosphorus Fractions and Availability in an Albic Bleached Meadow Soil
Authors: Yang Wenjing , Hao Fanghua , Cheng Hongguang , Lin Chunye , Ouyang Wei
Published: July 2013

The availability and mobility of P in soils is dependent on its chemical form. The objectives of this study were to investigate P fractions and availability in albic bleached luvisol meadow soils. Soil samples were collected from the albic bleached luvisol meadow soils (Albaqualfs) of the Sanjiang Plain in China and analyzed for total P (TP) as well as the forms and availability of P. The results showed that TP, inorganic P (Pinor), organic P (Por), and plant‐available P (AP) averaged 865.1, 452.4, 412.6, and 46.6 mg kg–1, respectively. In addition, soluble and loosely bound (S/L‐P), Al‐bound (Al‐P), Fe‐bound (Fe‐P), reductant‐soluble, and Ca‐bound P (Ca‐P) P, on average accounted for 0.3, 6.6, 27.9, 6.9, and 5.6%, respectively, of TP. The Pinor content was slightly higher than the Por content. Furthermore, approximately 53% of Pinor was composed of Fe‐P. The AP was significantly correlated with Pinor or “active” P but not correlated with Por. In addition, AP was correlated with Al‐P, Ca‐P, Fe‐P, and S/L‐P, with a maximum correlation coefficient of 0.792 for AP vs. Al‐P. Both the absolute content of AP and its proportion of TP were generally high in the albic bleached meadow soil of Sanjiang Plain. The P in the albic bleached luvisol meadow soil was mainly associated with Fe oxides and organic matter, and Fe‐P supports the majority of available P.
Insights into Genotype × Tillage Interaction Effects on the Grain Yield of Wheat and Maize
Authors: Herrera J. M. , Verhulst N. , Trethowan R. M. , Stamp P. , Govaerts B.
Published: July 2013

No tillage or zero tillage (NT) is the extreme form of reduced tillage; NT with residue retention is a main component of conservation agriculture. Using a literature survey and meta‐analysis, this study aimed to (i) summarize the results of studies comparing the grain yield of wheat [Triticum aestivum L. and Triticum turgidum L. subsp. durum (Desf.) Husn. (syn. Triticum durum Desf.)] and maize (Zea mays L.) genotypes under contrasting tillage, (ii) identify sources of variation in the grain yield response of wheat and maize genotypes to tillage practices, and (iii) identify potential traits for NT breeding programs. Grain yield was compared under NT and conventional tillage (CT) for 112 wheat genotypes (44 spring, 60 winter, and eight durum wheat genotypes) across 12 locations and 24 yr and for 93 maize hybrids across six locations and 5 yr. Most of these studies showed slightly higher grain yields under CT for maize (+5%) and winter (+5%) and spring (+2%) wheat. In the few studies where selection had been conducted under NT, the effect of tillage on the grain yield was modified significantly by genotypes. Traits associated with the emergence of vigorous seedlings and resistance to a changed spectrum of diseases increase genotype performance under NT. There is a need to evaluate genotypes developed under NT and extend the research on genotype performance under NT to locations with reduced input use and, in addition to tillage, investigate other factors that differentiate conservation agriculture from conventional practice.
Characterization of Populations of Turf‐Type Perennial Ryegrass Recurrently Selected for Superior Freezing Tolerance
Authors: Iraba Amandine , Castonguay Yves , Bertrand Annick , Floyd Donald J. , Cloutier Jean , Belzile François
Published: July 2013

Perennial ryegrass (Lolium perenne L.) is an important turfgrass species used for lawns, sports fields, and recreational areas. Insufficient tolerance to subfreezing temperatures compromises its persistence in northern climates. A recurrent selection method, entirely performed indoors, was applied to two initial genetic backgrounds to generate populations putatively more tolerant to freezing (TF populations). The objective of the present study was to assess physiological and molecular responses after four cycles of selection (TF1–TF4). Freezing tolerance and cold‐induced metabolites were monitored in plants hardened to natural variations in temperatures in fall and winter in an unheated greenhouse. Recurrent selection improved freezing tolerance expressed as the lethal temperature for 50% of the plants (LT50) and the vigor of regrowth after freezing. Significant changes in the levels of total and individual cold‐induced carbohydrates (fructans) and amino acids (glutamine and proline) in crowns of hardened plants occurred in response to selection. Both groups of metabolites showed an opposite response to selection. The observation of DNA polymorphisms and progressive genetic differentiation between the initial populations and advanced cycles of selection suggests an impact of selection on allelic composition. Recurrent selection had a positive impact on freezing tolerance of perennial ryegrass through modifications in the molecular and genetic makeup of the populations.
Advances in Soil Ecosystem Services: Concepts, Models, and Applications for Earth System Life Support
Authors: Robinson D.A. , Jackson B.M. , Clothier B.E. , Dominati E.J. , Marchant S.C. , Cooper D.M. , Bristow K.L.
Published: July 2013

The ecosystem services approach is gaining wide acceptance at the policy‐making level as a framework for integrating science and policy regarding the natural environment. It is important that soil science clearly articulates how knowledge and understanding of the vadose zone soils can be transmitted through this framework into the decision‐making process. Competition between food production, living space, and maintaining habitat for all of earth's life‐forms has never been so intense, so the need for soil security and vadose zone protection is paramount. Soil management can no longer be thought of in terms of single function management but instead needs to be considered and managed in the context of the multiple functions it offers. In this 10th anniversary issue of the journal, we assess progress in the development of a coherent soil ecosystem services framework using the natural resource management stock‐flow and fund‐service resource approach. We go on to examine some of the areas where the application of an ecosystems approach is gaining traction, which include national and local decision making as well as support for legal arguments in court.
Modelling of point and diffuse pollution: application of the Moneris model in the Ipojuca river basin, Pernambuco State, Brazil
Authors: de Lima Barros Alessandra Maciel , do Carmo Sobral Maria , Gunkel Günter
Published: July 2013

Emissions of pollutants and nutrients are causing several problems in aquatic ecosystems, and in general an excess of nutrients, specifically nitrogen and phosphorus, is responsible for the eutrophication process in water bodies. In most developed countries, more attention is given to diffuse pollution because problems with point pollution have already been solved. In many non-developed countries basic data for point and diffuse pollution are not available. The focus of the presented studies is to quantify nutrient emissions from point and diffuse sources in the Ipojuca river basin, Pernambuco State, Brazil, using the Moneris model (Modelling Nutrient Emissions in River Systems). This model has been developed in Germany and has already been implemented in more than 600 river basins. The model is mainly based on river flow, water quality and geographical information system data. According to the Moneris model results, untreated domestic sewage is the major source of nutrients in the Ipojuca river basin. The Moneris model has shown itself to be a useful tool that allows the identification and quantification of point and diffuse nutrient sources, thus enabling the adoption of measures to reduce them. The Moneris model, conducted for the first time in a tropical river basin with intermittent flow, can be used as a reference for implementation in other watersheds.
Going for mainstream deammonification from bench to full scale for maximized resource efficiency
Authors: Wett B. , Omari A. , Podmirseg S. M. , Han M. , Akintayo O. , Gómez Brandón M. , Murthy S. , Bott C. , Hell M. , Takács I. , Nyhuis G. , O'Shaughnessy M.
Published: July 2013

A three-pronged coordinated research effort was undertaken by cooperating utilities at three different experimental scales investigating bioaugmentation, enrichment and performance of anammox organisms in mainstream treatment. Two major technological components were applied: density-based sludge wasting by a selective cyclone to retain anammox granules and intermittent aeration to repress nitrite oxidizers. This paper evaluates process conditions and operation modes to direct more nitrogen to the resource-saving metabolic route of deammonification.
Use of papaya seeds as a biosorbent of methylene blue from aqueous solution
Authors: Paz Diego S. , Baiotto Alexandre , Schwaab Marcio , Mazutti Marcio A. , Bassaco Mariana M. , Bertuol Daniel A. , Foletto Edson L. , Meili Lucas
Published: July 2013

In this study papaya seeds were used to remove methylene blue dye from aqueous solution. Papaya seeds were characterized as possessing a macro/mesoporous texture and large pore size. Studies were carried out in batches to evaluate the effect of contact time and pH (2–12) on the removal of dye. It was observed that the adsorption of dye was better in the basic region (pH 12). The equilibrium data were analyzed using Langmuir, Freundlich, Dubinin–Raduschkevich, Tempkin, Jovanovich, Redlich–Peterson, Sips, Toth and Radke–Prausnitz isotherms. The equilibrium data were best described by the Langmuir isotherm with a maximum adsorption capacity of 637.29 mg g–1. Adsorption kinetic data were fitted using the pseudo-first-order and pseudo-second-order model. The adsorption kinetic is very fast and was best described by the pseudo-second-order model.
Assessment of nitrogen and phosphorus removal in an intermittently aerated sequencing batch reactor (IASBR) and a sequencing batch reactor (SBR)
Authors: Pan Min , Chen Tianhu , Hu Zhenhu , Zhan Xinmin
Published: July 2013

Biological nitrogen and phosphorus removal was investigated in an intermittently aerated sequencing batch reactor (IASBR) and a sequencing batch reactor (SBR). The removal efficiencies of ammonium-nitrogen (NH4+-N) were 100% in both reactors in steady operation state. The total nitrogen (TN) removal efficiencies were 90.4% in the IASBR and 79.3% in the SBR, while the total phosphorus (TP) removal efficiencies were 88.8% in the IASBR and 82.3% in the SBR. The efficiencies of simultaneous nitrification and denitrification (SND) were 90.4% in the IASBR and 79.3% in the SBR, indicating that the IASBR was more efficient than the SBR in SND. The sludge in the IASBR had a P release capability of 16.6 mg P/g VSS (volatile suspended solids) but only 7.5 mg P/g VSS in the SBR.
Effects of lipid composition on partitioning of fullerene between water and lipid membranes
Authors: Ha Yeonjeong , Liljestrand Howard M. , Katz Lynn E.
Published: July 2013

Fullerene partition coefficients (Klipw) between water and solid supported lipid membranes were determined for membranes of various lipid types and composition over a range of temperatures. The log Klipw (L/kg) values for fullerene, which range from 3.1 to 5.3, depend on the lipid type in the lipid membranes. Partition coefficients increased with increasing temperature, increasing acyl chain length of unsaturated lipids. The results indicate that lipid composition is a critical factor for bioconcentration of fullerene.
Microorganism inactivation by an ozonation step optimized for micropollutant removal from tertiary effluent
Authors: Schaar H. , Sommer R. , Schürhagl R. , Yillia P. , Kreuzinger N.
Published: July 2013

This paper demonstrates the additional benefit of the microbicidal efficacy of an ozonation plant implemented for micropollutant removal from tertiary effluent. Due to the low amount of viruses and protozoa in the tertiary effluent, bacteriophage MS2 and spores of Bacillus subtilis were dosed as surrogates. At specific ozone consumptions of 0.6 and 0.9 g O3/g dissolved organic carbon (DOC) a 2-log colony forming unit (CFU) reduction was achieved for indigenous Escherichia coli and enterococci, and the limits of the European bathing water directive for the excellent quality of inland waters were met. Higher removal was impeded by the shielding effect of suspended solids in the effluent, which implies the combination of ozonation with a preceding filtration step if higher microbicidal performances are required. The surrogate virus MS2 was reduced by 4–5 log while no significant inactivation was detected for B. subtilis spores. Additionally, the impact of ozonation on the biochemical oxygen demand (BOD) was studied. The BOD5 measurement was not adversely affected despite the reduced concentration of microorganisms after ozonation. The intrinsic increase in BOD5 averaged 15% at 0.6–0.7 g O3/g DOC. The impact of the projected increase on the surface water quality is generally not considered a problem but has to be assessed on a case-by-case approach.
Phytoplankton and bacterioplankton abundances and community dynamics in Lake Erhai
Authors: Mingming Hu , Yanhui Li , Yuchun Wang , Huaidong Zhou , Yongding Liu , Gaofeng Zhao
Published: July 2013

The composition and seasonal variation of the phytoplankton and bacterioplankton community were investigated, and SPSS and redundancy analysis (RDA) were used to explore the relationship between the phytoplankton and bacterioplankton community dynamics in the typical plateau Lake of Lake Erhai from July 2009 to April 2010. Obvious seasonal variation of phytoplankton was observed, and the abundance of phytoplankton ranged from 2.02 × 106 to 57.9 × 106 cells/L. The dominant species in autumn and summer was Microcystis sp., Psephonema aenigmaticum Skuja was dominant in winter, and Microcystis sp., Aphanizonmenon flos-aquae, Asterionella sp., P. aenigmaticum, etc. were dominant in spring. The abundance of bacterioplankton in the whole lake changed between 1.93 × 109 and 4.61 × 109 cells/L showing distinct seasonal variation characteristics. The results of correlation and RDA indicated that the abundance and community diversity of bacterioplankton were significantly correlated with the abundance of phytoplankton, and the group of Bacteroidetes had obvious correlation with Microcystis sp. and other cyanobacteria, which might have some links with the harmful algal blooms in Lake Erhai. Further research is needed to study the mechanisms of interactions between phytoplankton and bacterioplankton communities.
Physically based closed-form expression for the bimodal unsaturated hydraulic conductivity function
Authors: Liu Shiyu , Yasufuku Noriyuki , Liu Qiang , Hemanta Hazarika
Published: July 2013

Simulation of flow and contaminant transport through the vadose zone requires accurate parameterization of the soil hydraulic properties. This requirement is particularly important for soils with a complex structure. In the present study, a physically based closed-form expression for the bimodal unsaturated hydraulic conductivity function is proposed for soils with bimodal pore-size distribution. It combines the bimodal representation of the soil-water characteristic curve (SWCC) function of Liu with the conductivity representation model of Mualem. The proposed equations are defined by parameters that have physical significance, which can be related to the properties of the materials. Experimental data for the representation of bimodal SWCCs and corresponding hydraulic conductivity curves were used to demonstrate the applicability of the proposed functions. The proposed approaches resulted in good agreement with experimental data. These functions can potentially be used as an effective tool for identifying hydraulic porosities in mediums with a complex structure.
Effect of environmental factors on allelopathic inhibition of Microcystis aeruginosa by berberine
Authors: Zhang Shulin , Dai Wei , Bi Xiangdong , Zhang Dajuan , Xing Kezhi
Published: July 2013

To understand how environmental conditions affect the allelopathic inhibition of toxic Microcystis aeruginosa by berberine, the independent effects of some environmental factors, including temperature, light, and aeration, on the growth and extracellular microcystin (MC) content of M. aeruginosa (FACHB 905) treated with 0.000 and 0.001% (w/v) berberine were investigated. The results showed that higher temperature and light density, and aeration in daytime were beneficial for the growth of M. aeruginosa under the measured environmental conditions. The allelopathic effects of berberine on M. aeruginosa were closely associated with the environmental conditions. Berberine had the best inhibitory effects when temperature, light and aeration were more optimal for growth. In darkness, no changes in the density of M. aeruginosa were observed with the prolongation of culture time and berberine could hardly exhibit algicidal effects. Disturbance in the photosynthesis process might be one of the main reasons responsible for algicidal function. Berberine could increase extracellular MC contents significantly via killing and lyzing algal cells. Other treatments coupled with berberine needed to be carried out to degrade or remove MC released from berberine-killed algal cells.