bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling the effects of pulsed versus chronic sand inputs on salmonid spawning habitat in a low‐gradient gravel‐bed river
Authors: Maturana Oscar , Tonina Daniele , McKean James A. , Buffington John M. , Luce Charles H. , Caamaño Diego 
Published: October 2013

ABSTRACTIt is widely recognized that high supplies of fine sediment, largely sand, can negatively impact the aquatic habitat quality of gravel‐bed rivers, but effects of the style of input (chronic vs. pulsed) have not been examined quantitatively. We hypothesize that a continuous (i.e. chronic) supply of sand will be more detrimental to the quality of aquatic habitat than an instantaneous sand pulse equal to the integrated volume of the chronic supply. We investigate this issue by applying a two‐dimensional numerical model to a 1 km long reach of prime salmonid spawning habitat in central Idaho. Results show that in both supply scenarios, sand moves through the study reach as bed load, and that both the movement and depth of sand on the streambed mirrors the hydrograph of this snowmelt‐dominated river. Predictions indicate greater and more persistent mortality of salmonid embryos under chronic supplies than pulse inputs, supporting our hypothesis. However, predicted mortality varies both with salmonid species and location of spawning. We found that the greatest impacts occur closer to the location of the sand input under both supply scenarios. Results also suggest that reach‐scale morphology may modulate the impact of sand loads, and that under conditions of high sand loading climate‐related increases in flow magnitude could increase embryo mortality through sand deposition, rather than streambed scour. Copyright © 2013 John Wiley & Sons, Ltd.
Terrestrial laser scanning of rock slope instabilities
Authors: Abellán Antonio , Oppikofer Thierry , Jaboyedoff Michel , Rosser Nicholas J. , Lim Michael , Lato Matthew J. 
Published: October 2013

ABSTRACTThis manuscript presents a review on the application of a remote sensing technique (terrestrial laser scanning, TLS) to a well‐known topic (rock slope characterization and monitoring). Although the number of publications on the use of TLS in rock slope studies has rapidly increased in the last 5–10 years, little effort has been made to review the key developments, establish a code of best practice and unify future research approaches. The acquisition of dense 3D terrain information with high accuracy, high data acquisition speed and increasingly efficient post‐processing workflows is helping to better quantify key parameters of rock slope instabilities across spatial and temporal scales ranging from cubic decimetres to millions of cubic metres and from hours to years, respectively. Key insights into the use of TLS in rock slope investigations include: (a) the capability of remotely obtaining the orientation of slope discontinuities, which constitutes a great step forward in rock mechanics; (b) the possibility to monitor rock slopes which allows not only the accurate quantification of rockfall rates across wide areas but also the spatio‐temporal modelling of rock slope deformation with an unprecedented level of detail. Studying rock slopes using TLS presents a series of key challenges, from accounting for the fractal character of rock surface to detecting the precursory deformation that may help in the future prediction of rock failures. Further investigation on the development of new algorithms for point cloud filtering, segmentation, feature extraction, deformation tracking and change detection will significantly improve our understanding on how rock slopes behave and evolve. Perspectives include the use of new 3D sensing devices and the adaptation of techniques and methods recently developed in other disciplines as robotics and 3D computer‐vision to rock slope instabilities research. Copyright © 2013 John Wiley & Sons, Ltd.
Biotransformation pathways of fluorotelomer-based polyfluoroalkyl substances: A review
Authors: Butt Craig M. , Muir Derek C.G. , Mabury Scott A. 
Published: October 2013

Abstract

The study reviews the current state of knowledge regarding the biotransformation of fluorotelomer-based compounds, with a focus on compounds that ultimately degrade to form perfluoroalkyl carboxylates (PFCAs). Most metabolism studies have been performed with either microbial systems or rats and mice, and comparatively few studies have used fish models. Furthermore, biotransformation studies thus far have predominately used the 8:2 fluorotelomer alcohol (FTOH) as the substrate. However, there have been an increasing number of studies investigating 6:2 FTOH biotransformation as a result of industry's transition to shorter-chain fluorotelomer chemistry. Studies with the 8:2 FTOH metabolism universally show the formation of perfluorooctanoate (PFOA) and, to a smaller fraction, perfluorononanoate (PFNA) and lower-chain-length PFCAs. In general, the overall yield of PFOA is low, presumably because of the multiple branches in the biotransformation pathways, including conjugation reactions in animal systems. There have been a few studies of non-FTOH biotransformation, which include polyfluoroalkyl phosphates (PAPs), 8:2 fluorotelomer acrylate (8:2 FTAC), and fluorotelomer carboxylates (FTCAs, FTUCAs). The PAPs compounds and 8:2 FTAC were shown to be direct precursors to FTOHs and thus follow similar degradation pathways. Environ Toxicol Chem 2014;33:243–267. © 2013 SETAC
Effect of gold nanoparticles and ciprofloxacin on microbial catabolism: a community-based approach
Authors: Weber Kela P. , Petersen Elijah J. , Bissegger Sonja , Koch Iris , Zhang Jun , Reimer Kenneth J. , Rehmann Lars , Slawson Robin M. , Legge Raymond L. , O'Carroll Denis M. 
Published: October 2013

Abstract

The effect of gold nanoparticles (AuNPs) and ciprofloxacin on the catabolism of microbial communities was assessed. This was accomplished through an ex situ methodology designed to give a priori knowledge on the potential for nanoparticles, or other emerging contaminants, to affect the catabolic capabilities of microbial communities in the environment. Microbial communities from a variety of sources were incubated with 31 prespecified carbon sources and either National Institute of Standards and Technology reference material 10-nm AuNPs or ciprofloxacin on 96-well microtiter plates. From the ciprofloxacin study, dose−response curves were generated and exemplified how this method can be used to assess the effect of a toxicant on overall catabolic capabilities of microbial communities. With 10-nm AuNPs at concentrations ranging from 0.01 µg/mL to 0.5 µg/mL, rhizosphere communities from Typha roots were only slightly catabolically inhibited at a single concentration (0.05 µg/mL); no effects were seen on wetland water communities, and a minor positive (i.e., enhanced catabolic capabilities) effect was observed for loamy soil communities. This positive effect might have been because of a thin layer of citrate found on these AuNPs that initiated cometabolism with some of the carbon sources studied. Under the conditions considered, the possible adverse effects of AuNPs on the catabolic capabilities of microbial communities appears to be minimal. Environ Toxicol Chem 2013;33:44–51. © 2013 SETAC
Avoidance and reproduction tests with the predatory mite Hypoaspis aculeifer: Effects of different chemical substances
Authors: Owojori Olugbenga J. , Waszak Karolina , Roembke Joerg 
Published: October 2013

Abstract

Few toxicity data exist in the literature on the toxicity of chemicals to the predatory mite Hypoaspis aculeifer, but no information is available on its avoidance response. To assess the relevance of the avoidance behavior of H. aculeifer and the relative sensitivity of the mite in comparison with other invertebrates, avoidance and reproduction tests were conducted with 7 chemicals using standardized guidelines. The chemicals (deltamethrin, chloropyrifos, dimethoate, Cu, NaCl, phenanthrene, and boric acid) were selected so as to cover varying chemical classes. For all 3 pesticides tested, avoidance response showed lower sensitivity than reproduction and survival (avoidance median effective concentration [EC50] &gt; reproduction EC50/median lethal concentration [LC50] values). However, for Cu, NaCl, and phenanthrene, the avoidance response showed similar sensitivity as reproduction (avoidance EC50 ≤ reproduction EC50 values), whereas for boric acid, similar sensitivity as survival (avoidance EC50 ≤ LC50 values). Although the mite H. aculeifer appears less sensitive to some of the chemicals tested than most other soil invertebrates, its status as the only predator among organisms for which standardized tests are available affirms its inclusion in routine ecotoxicity assessment. The results of the avoidance test with H. aculeifer suggest its potential usefulness as a rapid screening test for risk assessment purposes. Environ Toxicol Chem 2014;33:230–237. © 2013 SETAC
Design and implementation of distributed load balancing and fast handoff for wireless mesh networks
Authors: Athanasiou George , Tassiulas Leandros 
Published: October 2013

AbstractThe association/handoff procedures are very important towards achieving a balanced operation in 802.11‐based wireless mesh networks. In this paper, we design and implement a cooperative association/handoff scheme, where stations share useful information, and handoff is executed in a seamless manner. Furthermore, we introduce a cross‐layer load balancing mechanism that takes into account uplink and downlink channel conditions, routing performance and congestion control. The proposed heuristic algorithms are inspired by the rapidly designed cooperative protocols and control the communication load of each mesh access point in a distributed manner. We evaluate the performance of our mechanisms through OPNET (www.opnet.com) simulations and testbed experiments. Copyright © 2013 John Wiley & Sons, Ltd.
Reconciling privacy and efficient utility management in smart cities
Authors: Rebollo‐Monedero David , Bartoli Andrea , Hernández‐Serrano Juan , Forné Jordi , Soriano Miguel 
Published: October 2013

ABSTRACTA key aspect in the design of smart cities is, undoubtedly, a plan for the efficient management of utilities, enabled by technologies such as those entailing smart metering of the residential consumption of electricity, water or gas. While one cannot object to the appealing advantages of smart metering, the privacy risks posed by the submission of frequent, data‐rich measurements cannot simply remain overlooked. The objective of this paper is to provide a general perspective on the contrasting issues of privacy and efficient utility management, by surveying the main requirements and tools, and by establishing exploitable connections. Copyright © 2013 John Wiley & Sons, Ltd.
A simplified model on vertical density profile and shrinkage ratio of virgin and charred medium density fibreboard
Authors: Li Kai Yuan , Cheng Xudong , Zhang Heping 
Published: October 2013

ABSTRACTThis work is part of a wider scope of research on developing comprehensive pyrolysis model for medium density fibreboard (MDF) in fires. A simplified model is developed to predict the vertical density profile of virgin MDF. The model shows that vertical density profile can be reproduced using a second order conic curve. Several sets of experimental data are used to validate the model with promising results that are presented. Further investigation shows that the density difference between surface and core densities tends to maintain constant within a range of 300 to 450 kg/m3. Moreover, the model can predict the mean density with an error less than 30 kg/m3. Typical MDF panels were experimentally charred using thermogravimetric analysis and cone calorimetry to investigate the shrinkage and density of char. The actual char density is measured as 330 kg/m3 with a uniform density distribution along the char layer thickness. A model is developed to predict the shrinkage ratios. The restraining effect caused by surface deformation will lead to different vertical and horizontal shrinkage ratios. The volume reductions at vertical and horizontal directions are experimentally measured as 40% and 20% for the two tested MDF panels, which is comparable with the model predictions. Copyright © 2013 John Wiley & Sons, Ltd.
Accuracy and stability analysis of a second‐order time‐accurate loosely coupled partitioned algorithm for transient conjugate heat transfer problems
Authors: Kazemi‐Kamyab V. , van Zuijlen A. H. , Bijl H. 
Published: October 2013

SUMMARYIn this paper, a second‐order time‐accurate loosely coupled partitioned algorithm is presented for solving transient thermal coupling of solids and fluids, also referred to by conjugate heat transfer. The Crank–Nicolson scheme is used for time integration. The accuracy and stability of the loosely coupled solution algorithm are analyzed analytically. Based on the accuracy analysis, the design order of the time integration scheme is preserved by following a predictor (implicit)–corrector (explicit) approach. Hence, the need to perform an additional implicit solve (a subiteration) at each time step is avoided. The analytical stability analysis shows that by using the Crank–Nicolson scheme for time integration, the partitioned algorithm is unstable for large Fourier numbers, unlike the monolithic approach. Accordingly, using the stability analysis, a stability criterion is obtained for the Crank–Nicolson scheme that imposes restriction on Δt given the material properties and mesh spacings of the coupled domains. As the ratio of the thermal effusivities of the coupled domains reaches unity, the stability of the algorithm reduces. To demonstrate the applicability of the algorithm, a numerical example is considered (an unsteady conjugate natural convection in an enclosure). Copyright © 2013 John Wiley & Sons, Ltd.
Unconditionally stable numerical simulations of a new generalized reduced resistive magnetohydrodynamics model
Authors: Malapaka Shiva Kumar , Després Bruno , Sart Rémy 
Published: October 2013

SUMMARYReduced‐resistive magnetohydrodynamics (MHD) models are used in understanding different phenomenon in various domains, for example, astrophysics to model magnetotail or for solar arcades [Finn Bozkaya JM, Guzdar PN. Loss of equilibrium and reconnection in tearing of two dimensional equilibrias. Physics of Fluids B 1993; 5:2870–2876], modeling plasma confinements in reverse field pinch [Strauss HR. The dynamo effect in fusion plasmas. Physics of Fluids 1985; 28:2786–2792] and tokamaks [Strauss HR. Reduced MHD in nearly potential magnetic fields. Journal of Plasma Physics 1997; 57(1):83–87; Freidberg J. Plasma Physics and Fusion Energy. Cambridge University Press: Cambridge, 2008]. In this context, recently, a new generalized reduced‐resistive MHD model, which can make use of an arbitrary density profile was proposed [Després B, Sart R. Reduced resistive MHD in Tokamaks with general density. ESAIM: Mathematical Modelling and Numerical Analysis 2012; 46(5):1081–1106. EDP Sciences, SMAI, 2012 online 2011]. We in this work show that this proposed theoretical model can be realized numerically as well, and that it is very robust if the equation set is written in a very particular form using the properties of FEM. To illustrate these points, we pick the current hole configuration [Fujita T, Oikawa T, Suzuki T, Ide S, Sakamoto Y, Koide Y, Hatae T, Naito O, Isayama A, Hayashi N, Shirai H. Plasma equilibrium and confinement in a tokamak with nearly zero central current density in JT‐60U. Physical Review Letters 2001; 87(11):245001; Hawkes NC, Stratton BC, Tala T, Challis CD, Conway G, DeAngelis R, Giroud C, Hobirk J, Joffrin E, Lomas P, Lotte P, Mailloux J, Mazon D, Rachlew E, Reyes‐Cortes S, Solano E, Zastrow K‐D. Observation of zero current density in the core of JET discharges with lower hybrid heating and current drive. Physical Review Letters 2001; 87(11):115001], which was modeled using reduced‐resistive MHD and remodel it using different combinations of current sources and density profiles. Our model can be implemented with reasonable computational resources at the price of solving a well‐posed global linear system and it is unconditionally stable. These features are also demonstrated as a part of our numerical experiments. Copyright © 2013 John Wiley & Sons, Ltd.
The inhibitory effect of a fermented papaya preparation on growth, hydrophobicity, and acid production of Streptococcus mutans, Streptococcus mitis, and Lactobacillus acidophilus: its implications in oral health improvement of diabetics
Authors: Somanah Jhoti , Bourdon Emmanuel , Bahorun Theeshan , Aruoma Okezie I. 
Published: October 2013

AbstractFermented papaya preparation (FPP) is a “natural health product.” The high incidence of dental caries, gingivitis, periodontitis, and oral microbial infection cases among patients with diabetes mellitus continues to prevail. The potential role of FPP against common oral microbiota (Streptococcus mutans, Streptococcus mitis, and Lactobacillus acidophilus) isolated from the human oral cavity was investigated using in vitro simulation models of dental plaque and caries. FPP showed an inhibitory effect against the growth (at 0.05 mg/mL: S. mutans: −6.9%; S. mitis: −4.47%, P < 0.05), acid production (at 0.05 mg/mL: S. mutans: +6.38%; L. acidophilus: +2.25%), and hydrophobicity (at 50 mg/mL: S. mutans: 1.01%, P < 0.01; S. mitis: 7.66%, P < 0.05) of tested microbiota. The results of this study suggest that low doses of FPP may be a suitable complement to good oral hygiene practice for the effective prevention of dental caries, plaque, and gingivitis. The functional application of FPP as a constituent of a balanced diet and active lifestyle can make a positive contribution to the oral health status and well‐being of patients with diabetes.
Long‐Term Stability Studies of Anode‐Supported Microtubular Solid Oxide Fuel Cells
Authors: Laguna‐Bercero M. Á. , Férriz A. , Larrea Á. , Correas L. , Orera V. M. 
Published: October 2013

AbstractA long‐term stability study of an anode‐supported NiO/YSZ‐YSZ‐LSM/YSZ microtubular cell was performed, under low fuel utilization conditions, using pure humidified hydrogen as fuel at the anode side and air at the cathode side. A first galvanometric test was performed at 766 °C and 200 mA cm–2, measuring a power output at 0.5 V of ∼250 mW cm–2. During the test, some electrical contact breakdowns at the anode current collector caused sudden current shutdowns and start‐up events. In spite of this, the cell performance remains unchanged. After a period of 325 h, the cell temperature and the current density was raised to 873°C and 500 mA cm–2, and the cell power output at 0.5 V was ∼600 mW cm–2. Several partial reoxidation events due to disturbance in fuel supply occurred, but no apparent degradation was observed. On the contrary, a small increase in the cell output power of about 4%/1,000 h after 654 h under current load was obtained. The excellent cell aging behavior is discussed in connection to cell configuration. Finally, the experiment concluded when the cell suffered irreversible damage due to an accidental interruption of fuel supply, causing a full reoxidation of the anode support and cracking of the thin YSZ electrolyte.
A comparison of water chemistry from a CO2‐enhanced oil recovery project with reactive transport modeling of CO2 injection into a carbonate reservoir
Authors: Shevalier Maurice , Nightingale Michael , Dalkhaa Chantsalmaa , Mayer Bernhard 
Published: October 2013

AbstractA long‐term geochemical monitoring program was conducted at a CO2‐enhanced oil recovery site in central Alberta (Canada) to examine geological storage of CO2. The program included geochemical monitoring of reservoir brines, a mineralogical study, and using TOUGHREACT to compare model and field observations. CO2 was injected into a highly permeable carbonate reservoir at 78 tonnes/day for 2.5 years. Fluid and gas samples were obtained for geochemical characterization before, during, and 1.4 years after injection from a production well ∼915 m from the injection well at a depth of ∼936 m. Downhole water compositions were calculated using SOLMINEQ88 and compared to predictions from TOUGHREACT. Following CO2 breakthrough after ∼23 months, downhole pH decreased, HCO3−; and calcium concentrations increased, while magnesium concentrations changed marginally, indicating solubility and ionic trapping were occurring simultaneously. Trends in analyzed and modeled species were similar, but concentration levels were different. Calibrating the model to achieve better correlation between results was attempted but proved unsuccessful. The variances were likely caused by differences between ideal and reservoir mineral's kinetic parameters, surface area, thermodynamic parameters and sampling technique. Five‐hundred‐year simulations showed the CO2 plume migrating vertically due to capillary forces with no significant change in gas saturation below the caprock over the post‐injection period. The majority of CO2 remained trapped as a supercritical phase as the reservoir is composed of only carbonate minerals. The low reactivity of the reservoir is positive, in that the reservoir is not negatively impacted by dissolution and negative in that no mineral trapping occurs. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd
Catalytic hydrolysis of trifluoromethane over alumina
Authors: Han Wenfeng , Chen Yuliang , Jin Bibo , Liu Huazhang , Yu Hai 
Published: October 2013

AbstractCatalytic hydrolysis over alumina was carried out at temperatures between 350 °C and 520 °C and gas hourly space velocity (GHSV) of 6000 h−1. The effects of water vapor concentration, alumina phase, and Zn promoter as well as the reaction mechanism were investigated in detail. The results show that the presence of small amounts of water vapor (0.8%) significantly improves the activity of γ‐Al2O3, while higher water vapor concentration (>2.8%) does not further enhance the decomposition of CHF3. Compared with γ‐Al2O3 and AlOOH, α‐Al2O3 is inactive for the targeted reaction although it is stable under conditions studied (with the presence of HF product). Zn is an efficient promoter for the improvement of activity and stability of alumina catalyst. More attention is paid to the reaction and deactivation mechanism. Based on the experimental results and thermodynamic analysis, a reaction mechanism is proposed which explains the effect of water vapor and deactivation of catalyst reasonably.