bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Simple Frontal Analysis Equation to Determine the Adsorption Parameters of Solute Molecules on Different Adsorbents
Authors: Bian Liu‐Jiao , Yang Xiao‐Yan , Liu Li 
Published: February 2007

AbstractA simple frontal analysis equation to determine the adsorption parameters of solute molecules on different adsorbents was presented. It gives the relationship between the average breakthrough time and the feed solute concentration, and by using its linear form, two important parameters, the thermodynamic equilibrium constant KSL for solute adsorption on the surface of adsorbent and the number nt of total adsorption sites distributed on the surface of adsorbent, can be simultaneously determined. The frontal analyses for some aromatic hydrocarbons on RP‐C18 reversed‐phase medium, and some protein molecules on RP‐C18 reversed‐phase, WCX‐1 cation‐exchange, PEG‐400 hydrophobic and Che1ating Sepharose Fast‐flow separately chelated with Zn2+ or Cu2+ media, were separately carried out to test this equation and their adsorption parameters KSL and nt were separately obtained. The results show that all these frontal analysis data can be well described by this frontal analysis equation. For all of these frontal analysis systems, their parameters nt can separately approximately keep constant and they are independent of solute molecules used, while their parameters KSL are dependent upon both of the media packed in frontal analysis column and the solute molecules used.
Convenient Synthesis and Enhanced Second‐order Nonlinear Optical Property of a Novel Hyperbranched Polymer
Authors: Zhu Zhi‐Chao , Li Zhong‐An , Li Qian‐Qian , Zeng Qi , Li Zhen , Ye Cheng , Qin Jin‐Gui 
Published: February 2007

AbstractA novel hyperbranched polymer (3) was prepared by copolymerization of tri‐aldehyde moieties with azo chromophores having two active methelene groups, from "A2+B3" approach based on simple Kneovenagel reaction. For comparison, its analogue linear polymer (5) was also synthesized. The two polymers are soluble in common organic solvents, and exhibit good thermal stability. Interestingly, the hyperbranched polymer demonstrates dramatically enhanced second‐order nonlinear optical property with comparison to its linear analogue.
An improved iterative SENSE reconstruction method
Authors: Qu Peng , Luo Jing , Zhang Bida , Wang Jianmin , Shen Gary X. 
Published: February 2007

AbstractThe conjugate‐gradient (CG)‐based non‐Cartesian SENSE reconstruction usually exhibits unstable convergence behavior due to the ill conditioning of the generalized encoding matrix (GEM). To overcome this difficulty, an improved iterative SENSE approach is presented. During a so‐called Lanczos iteration process, which is equally efficient as CG, the inversion of GEM can be gradually approximated by calculating inversions of a series of small tridiagonal matrices. In this fashion, inner regularization can be incorporated into the reconstruction without touching the iteration process. The degree of regularization can be determined based on the eigenvalue information provided by the Lanczos process. With inner regularization adaptively applied for every iteration vector, the convergence behavior of iterative SENSE can be significantly improved and noise amplification can be avoided. The feasibility of this novel iterative SENSE technique is demonstrated by radial and spiral MRI experiments. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 31B: 44–50, 2007
An eight‐channel, nonoverlapping phased array coil with capacitive decoupling for parallel MRI at 3 T
Authors: von Morze Cornelius , Tropp James , Banerjee Suchandrima , Xu Duan , Karpodinis Kostas , Carvajal Lucas , Hess Christopher P. , Mukherjee Pratik , Majumdar Sharmila , Vigneron Daniel B. 
Published: February 2007

AbstractAn eight‐channel, nonoverlapping phased array coil was designed for conventional and parallel imaging of the brain and the hip at 3T. The nonoverlapping design was selected on the basis of reduced parallel reconstruction noise inflation, as predicted by the diminution of g‐factor hotspots in SENSE reconstruction simulations, and the higher peripheral signal‐to‐noise ratio (SNR) expected from smaller coil elements. A capacitive bridging technique, modeled by a circuit simulation, reduced the crosstalk between nearest neighbors to a manageable level. The capacitive decoupling technique was effective enough to allow the coil to be operated using standard system preamplifiers. The coil was shown to be useful for several conventional and parallel imaging applications. SNR improvements over a commercial eight‐channel head coil were demonstrated in important structures in EPI‐SENSE diffusion‐weighted imaging. High‐resolution MRSI (0.22 cc) yielded SNR of up to 21 for the NAA peak in the cortical gray matter. The coil also provided excellent fourfold accelerated GRAPPA images of the hip. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 31B: 37–43, 2007
Two‐dimensional adaptive mesh generation
Authors: Zhang Yaoxin , Jia Yafei , Wang Sam S. Y. 
Published: February 2007

AbstractIn this paper, a two‐dimensional adaptive elliptic mesh generation system, derived from the Ryskin and Leal (RL) orthogonal mesh generation system based on the orthogonal condition (orthogonality) and the cell area equal‐distribution principle (adaptivity), is presented. The proposed generation system takes into account not only the mesh orthogonality and adaptivity but also the mesh smoothness by adopting a method that the distortion functions is determined by both the scale factors and the averaged scale factors of the constant mesh lines. Examples and application show that the proposed generation system is effective and easy to use. Copyright © 2007 John Wiley & Sons, Ltd.
A stress‐based least‐squares finite‐element model for incompressible Navier–Stokes equations
Authors: Prabhakar V. , Reddy J. N. 
Published: February 2007

AbstractIn this paper we present a stress‐based least‐squares finite‐element formulation for the solution of the Navier–Stokes equations governing flows of viscous incompressible fluids. Stress components are introduced as independent variables to make the system first order. Continuity equation becomes an algebraic equation and is eliminated from the system with suitable modifications. The h and p convergence are verified using the exact solution of Kovasznay flow. Steady flow past a large circular cylinder in a channel is solved to test mass conservation. Transient flow over a backward‐facing step problem is solved on several meshes. Results are compared with that obtained using vorticity‐based first‐order formulation for both benchmark problems. Copyright © 2007 John Wiley & Sons, Ltd.
Xylem sap flows of irrigated Tamarix elongata Ledeb and the influence of environmental factors in the desert region of Northwest China
Authors: Qu Yanping , Kang Shaozhong , Li Fusheng , Zhang Jianhua , Xia Guimin , Li Wangcheng 
Published: February 2007

AbstractTamarix elongata Ledeb is a desert shrub found in the desert region of Northwest China and is commonly cultivated as a sand‐holding plant in this region. To understand its water requirement and the effects of climate conditions on its growth, trunk xylem sap flows of irrigated 8‐year‐old Tamarix elongata Ledeb plants were monitored continuously with heat‐pulse sap flow meters for the entire season. Soil moisture contents at 0–300 cm layer depth were also measured with a tube type time domain reflectometry (Tube‐TDR). Meteorological factors, i.e. solar radiation, air temperature, relative humidity and wind speed were simultaneously monitored by an automatic weather station at the site. Daily and seasonal variations of the trunk sap fluxes and their correlations with the meteorological factors, reference evapotranspiration and soil moisture contents in the root‐zone were analysed. The results indicated that frost influenced the trunk sap flux greatly under irrigated conditions, although the flux generally fluctuated with the variation of environmental factors and showed a mean trunk sap flux of 4·18 l d−1. There was a significantly exponential relationship between sap flux and the reference value of crop evapotranspiration, with a correlation coefficient of R2 = 0·7172. The sap flux also had a significant correlation with the soil water contents at a depth of 150–300 cm from soil surface (R2 = 0·5014). The order of the main meteorological factors affecting the sap flux of Tamarix elongata Ledeb trees was solar radiation > air temperature > vapour pressure deficit > relative humidity > wind speed. Copyright © 2007 John Wiley & Sons, Ltd.
Microbial Food Webs in an Artificially Divided Acidic Bog Lake
Authors: Šimek Karel , Babenzien Dieter , Bittl Thomas , Koschel Rainer , Macek Miroslav , Nedoma Jiří , Vrba Jaroslav 
Published: February 2007

AbstractThe microbial loop of a naturally acidic bog lake, Große Fuchskuhle (Northeastern Germany), that had been artificially divided into 4 basins, was investigated. In the northeast (NE) and southwest (SW) basins, which differ strongly in chemistry and primary production, we conducted intensive studies of the main carbon fluxes through microbial food webs. In the less acidic, NE basin, much higher phytoplankton as well as bacterial biomass and production were found in parallel with negligible numbers of larger zooplankters. Weakly top‐down controlled populations of protists were characterized by an exceptionally low numerical proportion of heterotrophic nanoflagellates (HNF) to ciliates (‐1.5‐3.5). The ciliate community was dominated by a scuticociliate, Cyclidium sp. (>95% of total ciliates), with an estimated grazing rate equal to 46–80% of heterotrophic bacterial production. In contrast, in the more humic, SW basin, both phyto‐ and bacterioplankton dynamics seemed to be top‐down controlled by abundant populations of small fine‐filter feeding cladocerans, Ceriodaphnia quadrangula and Diaphanosoma brachyurum. Consequently, ciliates disappeared from the food web structure of the SW basin, HNF dropped to negligible numbers and bacteria showed very uniform morphology, dominated by small cocci or short rods. Our investigations have shown that the division of the lake into separate compartments can lead to very different microbial food web structures with extreme species compositions.
The Importance of the Manganese‐Oxidizing Microorganism Metallogenium personatum for the Retention of Manganese in the Wahnbach Reservoir
Authors: Herschel A. , Clasen J. 
Published: February 2007

AbstractThe retention of manganese in the water of the Wahnbach reservoir was determined in mass balance calculations. The retention properties for manganese drastically decreased after the phosphorus elimination plant was taken into service. Processes controlling the distribution and mobility of manganese in the reservoir were based on the results of tests conducted to evaluate the role of the microorganism Metallogenium personatum. A substantial retention of manganese in the Wahnbach reservoir was found to be dependent on the presence of this planktonic manganese‐oxidizing bacterium. The test results clearly indicate the importance of Metallogenium spec. as catalyst in the removal and oxidation of dissolved Mn(II).
An Unique Anchialine Pool in the Hawaiian Islands
Authors: Brock Richard E. , Bailey‐Brock Julie H. 
Published: February 2007

AbstractThe Sailor's Hat crater was artificially formed on the south coast of Kaho'olawe Island in 1965 with explosives. The explosion formed a crater about 50 m from the shoreline, which penetrates the watertable to a 5 m depth. The pool at the bottom of the crater meets the criteria of an anchialine pond because it shows tidal fluctuation, has measurable salinity, and lacks surface connections to the sea. The water chemistry of this pool is similar to the ocean except silica is elevated and salinity is slightly depressed suggesting a small groundwater influence. The fauna is dominated by waterboatmen, an endemic shrimp and tubeworm, polychaetes, amphipods, an ostracod, gastropod, solitary ectoproct. anemone, flatworm and sponge. The atyid shrimp, Halocaridina rubra, is a characteristic species of Hawaiian anchialine systems and probably colonized this 32‐year old pool by active migration via the watertable. Colonization by the remaining fauna may have occurred by storm surf (for marine species) or with the wind. Most predators are unable to inhabit anchialine ponds because of difficult access due to physical barriers, or to unsuitable ecological conditions. The anchialine habitat and life history strategy of the atyid shrimp have probably been important influences on the adaptative success of H. rubra in the Hawaiian Islands, and may be important characteristics of hypogeal anchialine species elsewhere.
Responses of Bacterial Assemblages on Standing‐Decaying Blades of Smooth Cordgrass to Additions of Water and Nitrogen
Authors: Newell Steven Y. , Palm Laura A. 
Published: February 2007

AbstractPlots of intermediate‐height cordgrass (Spartina alterniflora) were fertilized with nitrogen, misted with freshwater, given both misting and N, or left untreated. Bacterial responses on standing‐decaying leaf blades were measured as changes in epiphytic mass, rates of shedding of bacterial cells into seawater, and rates of net growth on blades. Epiphytic mass rose with time, and it did so 6‐fold more sharply for the combination of fertilization and misting than for control. Since the sediment surface would offer higher N and water availability, this may indicate that movement of leaf material to marsh sediments would strongly favor bacterial activity. Net growth on aerially incubated (15 h), wet blades as percentage of standing bacterial mass was unchanging with duration of decay period, but was affected by treatment (about 0 to +5% h−1 for misted treatments, +15% h−1 for unmisted treatments). Faster growth on newly wetted, unmisted blades may have been due to release of cells from growth limitation by desiccation. Plot treatment did not affect specific rate of bacterial shedding (about 8% of standing bacterial epiphytic mass during one h of submergence at 4 weeks, and 149% h−1 at 12 weeks). It may be that during high spring tides, bacterial shedding from standing‐decaying blades could provide numbers of new cells in the water column near to or greater than those provided by division of bacterioplanktonic cells.
A Method Based on Artificial Substrates to Monitor Hyporheic Biofilm Development
Authors: Claret Cecile 
Published: February 2007

AbstractA method based on artificial substrata is proposed to study hyporheic biofilm development as well as the procedure to remove bacteria from these biofilms. The device is a perforated pipe in which glass slides are introduced vertically. Attached bacteria are removed by sonication for 180 seconds at power 2 (arbitrary unit); longer sonication time or higher power can cause cell destruction. A bacterial colonization experiment was performed in an upwelling zone of a riffle in the Rhǒne River. Total bacterial abundances reached a steady‐state after 5 days of colonization, and the percentage of ETS‐active bacteria was maximal after 3 days of incubation in the bed sediments. These results validate this device as usable to monitor biofilm development in natural systems, making this method as a promising tool to characterize the trophic status of a stream using integrative biological descriptors.
Seasonal Dynamics of Bacterio‐ and Phytoplankton in Large and Shallow Eutrophic Lake Võrtsjärv, Estonia
Authors: Kisand Veljo , Nõges Tiina 
Published: February 2007

AbstractThe seasonal dynamics of bacterioplankton abundance, biomass and production was measured in the large (surface area 270 km2) and shallow (mean depth 2.8 m) Lake Võrtsjärv during one year. Bacterial biomass and heterotrophic activity (production) was measured using thymidine and leucine incorporation methods. The bacterial biomass production was estimated by leucine incorporation, the cell number production by thymidine incorporation. Primary production and photosynthetic extracellular release was measured simultaneously to evaluate their role on heterotrophic bacterial activity. Relationships between released fraction of primary production and heterotrophic bacteria, as well as between biomass of bacteria and biomass/composition of phytoplankton are discussed. In terms of the carbon balance, the total primary production could support carbon need of heterotrophic bacteria in Lake Võrtsjärv. Neither biomass nor activity of bacteria showed tight coupling to primary production over the whole investigation period. In spring and summer the relationship between bacterial production and primary production was weak. The development of cyanobacterial bloom in summer provided more substrates for heterotrophic bacteria than diatoms in spring. In autumn both activity of bacteria and algae decreased rapidly in a coupled manner.
Short Term Bioturbation Activity in the Lagoonal Sediments of Tikehau Atoll (Tuamotu Archipelago, French Polynesia)
Authors: Hily Christian , Frouin Patrick 
Published: February 2007

AbstractTo quantify bioturbation activity in Tikehau lagoon, a tracer made of black basaltic sand was poured over the natural white calcareous sediment surface. Three stations respectively located on the inner flat (‐3m), the inner slope (‐9m), and the lagoon floor (‐19m), were studied for short periods of time (48 hours). Bioturbation by macrofauna was quantified by volume of sediment ejected onto the experimental surface and by volume of tracer incorporated into sediment. The results showed a rapid incorporation of sedimented particles at the interface by way of the funnels and burrows of surface deposit feeders and carnivores. Expelled quantities varied with respect to site location: 213 cm3 · m−2 · 24 h−1 in the inner flat; 98.9 cm3 · m−2 · 24 h−1 in the inner slope; 7.9 m3 · m−2 · 24 h−1 in the lagoon floor. Bioturbation by decapod megafauna appeared to be important in the dynamics of the sediments in the deepest areas of the lagoon. In these areas, with almost no hydrodynamical impacts on sediments, bioturbating events were responsible for sediment mixing (despite lower absolute rates than in shallow area). Hydrodynamics controlled the spatial distribution of macroinvertebrate trophic groups by its effects on sedimentation.
Tendency of the Amphipod Gammarus roeseli Gervais to Colonize Coarse Sediment Habitats under Fish Predation Pressure
Authors: Starry Olyssa , Wanzenböck Josef , Danielopol Dan L. 
Published: February 2007

AbstractMany invertebrates react to the actual presence and/or to chemical cues from predators. However, there is lack of information on the interrelationship of different cues triggering the antipredator response. In a series of aquarium experiments we investigated to which extent the antipredator response of a freshwater amphipod (Gammarus roeseli), i.e. seeking refuge in coarse substrate, is influenced by the actual presence of a natural fish predator (the ruffe, Gymnocephalus cernuus) including mechanical and visual cues, purely chemical cues, as well as the thickness of the sediment layer. Presence of Gammarus roeseli on the substrate surface and activity was videotaped under different conditions and evaluated according to a standard protocol. Even without fish present and without fish chemicals Gammarus roeseli moved into the substrate because of thigmotactic behavior. The presence of ruffe accelerated this phenomenon and fish odor elicited weaker responses. Gammarus roeseli was able to recognize the approach of fish predators both visually and/or mechanically.
The ligand Jelly Belly (Jeb) activates the Drosophila Alk RTK to drive PC12 cell differentiation, but is unable to activate the Mouse ALK RTK
Authors: Yang Hai‐Ling , Eriksson Therese , Vernersson Emma , Vigny Marc , Hallberg Bengt , Palmer Ruth H. 
Published: February 2007

AbstractThe Drosophila Alk receptor tyrosine kinase (RTK) drives founder cell specification in the developing visceral mesoderm and is crucial for the formation of the fly gut. Activation of Alk occurs in response to the secreted ligand Jelly Belly. No homologues of Jelly Belly are described in vertebrates, therefore we have approached the question of the evolutionary conservation of the Jeb–Alk interaction by asking whether vertebrate ALK is able to function in Drosophila. Here we show that the mouse ALK RTK is unable to rescue a Drosophila Alk mutant, indicating that mouse ALK is unable to recognise and respond to the Drosophila Jeb molecule. Furthermore, the overexpression of a dominant‐negative Drosophila Alk transgene is able to block the visceral muscle fusion event, which an identically designed dominant‐negative construct for the mouse ALK is not. Using PC12 cells as a model for neurite outgrowth, we show here for the first time that activation of dAlk by Jeb results in neurite extension. However, the mouse Alk receptor is unable to respond in any way to the Drosophila Jeb protein in the PC12 system. In conclusion, we find that the mammalian ALK receptor is unable to respond to the Jeb ligand in vivo or in vitro. These results suggest that either (i) mouse ALK and “mouse Jeb” have co‐evolved to the extent that mALK can no longer recognise the Drosophila Jeb ligand or (ii) that the mALK RTK has evolved such that it is no longer activated by a Jeb‐like molecule in vertebrates. J. Exp. Zool. (Mol. Dev. Evol.) 308B:269–282, 2007. © 2007 Wiley‐Liss, Inc.
Oxidative Coupling Polymerization of Substituted Phenols with a Copper Amine Catalyst Immobilized within Mesoporous Silica
Authors: Shibasaki Yuji , Nakamura Masahiro , Kondo Junko N. , Ueda Mitsuru 
Published: February 2007

AbstractSBA‐15‐supported CuCl catalyst was prepared for the regio‐controlled oxidative polymerization of phenol derivatives. The solid‐supported catalyst was fully characterized by X‐ray, elemental analysis, TEM observation, and nitrogen absorption‐desorption experiment, and CuCl was found to be uniformly immobilized in the mesopores. This catalyst was employed for the oxidative polymerization of 2,5‐dimethylphenol and o‐cresol, resulting in excellent regio‐selectivity during the polymerization.
Natural Weathering Evaluation of LDPE‐Mango Starch Blends by Mechanical Properties and High Field NMR
Authors: Rodrigues Tathiane Cordeiro , Tavares Maria Inês Bruno , Pita Victor Jayme Roget Rodriguez 
Published: February 2007

AbstractThe low‐density polyethylene/mango starch blends were obtained and submitted a natural degradation. Their mechanical properties and structures changes were determined by tensile, low and high field nuclear magnetic resonance characterization after different weathering times. The exposition time and starch content could be correlated to the polymer matrix changes from void formation theories. The blend deformations were affected by the starch degradation time. The starch degradation, confirmed by nuclear magnetic resonance, could be able to form voids and improve the blends fragmentability at relative low weathering times.
Rheological Properties of Polystyrene‐Organophilic Layered Silicate Nanocomposites
Authors: Han Seung San , Kim Yong Seok , Lee Sung Goo , Lee Jae Heung , Zhang Ke , Choi Hyoung Jin 
Published: February 2007

AbstractA series of nanocomposites based on polystyrene (PS) and organophilic layered silicates (OLS) were prepared by solution blending method using organophilically modified silicate with ammonium salt of poly(styrene‐ran‐(4‐vinylbenzyl chloride)). Two different types of base layered silicate were used for the preparation of the nanocomposites: sodium montmorillonite (Na‐MMT) and synthetic smectite (SWN). The morphology and thermal stability of the PS/OLS nanocomposites were characterized by TEM and TGA. The rheological properties of the nanocomposites were investigated using a stress‐controlled rotational rheometer under small amplitude oscillation and steady transient shear in their melt state. In addition, the effects of the contents and aspect ratio of OLS on the melt rheological properties were investigated.