bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Structural Characterization, Electronic Structure, and Magnetic Properties of the Zintl Phase Eu10Cd6Bi12
Authors: Xia Sheng‐qing , Bobev Svilen 
Published: April 2007

AbstractA new transition‐metal‐containing Zintl phase, Eu10Cd6Bi12, was synthesized by combining the elements in excess molten Cd. Single‐crystal X‐ray diffraction studies indicated that this compound crystallizes in the orthorhombic space group Cmmm (No. 65) with a=7.840(2), b=24.060(7), and c=4.7809(14) Å. The crystal structure of Eu10Cd6Bi12 can be viewed as a stacking of a series of [Cd6Bi12] double layers, which are arranged alternately along the b axial direction. The layers are composed of corner‐ and edge‐shared CdBi4 tetrahedra, a common feature in the crystal chemistry of many transition‐metal Zintl phases. Electronic‐band‐structure calculations confirm the closed‐shell configuration of all constituent elements and corroborate the electron count inferred by the Zintl formalism, that is, [Eu2+]10[Cd2+]6[Bi3−]8[Bi2−]4. Magnetic‐susceptibility measurements confirm the divalency of europium and show the existence of a long‐range antiferromagnetic order of the Eu spins below 12.3 K.
Agricultural Waste Conversion to Activated Carbon by Chemical Activation with Phosphoric Acid
Authors: Soleimani M. , Kaghazchi T. 
Published: April 2007

AbstractActivated carbon is widely used in various processes as an inexpensive and effective adsorbent. The adsorption properties of activated carbon vary with the feed materials used and the method of activation. The use of an inexpensive material and performing a suitable production method may help to generate a low cost product. Agricultural wastes could be considered as suitable raw materials for the production of activated carbon. In this work, activated carbon was produced by chemical activation with phosphoric acid of agricultural wastes such as bagasse, hard shells of apricot stones, almond, walnut and hazelnut shells. The effects of various preparation variables on both yield and quality of the prepared carbon were studied. The results showed that the selection of final activation temperature, heating rate, activation time and impregnation rate of the chemical agent was important in determining the quality of activated carbon obtained. The surface area and ash content of the activated carbon produced were compared to those of imported commercial samples. According to the results obtained, activated carbon from the hard shells of apricot stones have the best adsorption properties and the highest surface area. This activated carbon could be used in the separation of metal ions from wastewaters.
Phenol Removal through Chemical Oxidation using Fenton Reagent
Authors: Yavuz Y. , Savas Koparal A. , Bakir Ögütveren Ü. 
Published: April 2007

AbstractIn this study, phenol, aromatic, and non‐biodegradable organic matter were investigated and found to be removed from the model solution through chemical oxidation using Fenton reagent. The effects of the initial phenol concentration, hydrogen peroxide, and ferrous sulfate concentrations on the removal efficiency were investigated. Performance of the chemical oxidation process was monitored with phenol and COD (Chemical Oxygen Demand) analyses. In the experimental studies, phenol removal of over 98 % and COD removal of nearly 70 % were achieved. The optimum conditions for Fenton reaction both for initial phenol concentrations of 200 and 500 mg/L were found at a ratio [Fe2+]/[H2O2] (mol/mol) equal to 0.11. According to the results, chemical oxidation using Fenton reagent was found to be too effective, especially for phenol removal. However, this method has limited removal efficiency for COD.
Finite Volume Simulation of High Speed Combustion of Premixed Air‐Acetylene Mixtures in a Microchannel
Authors: Chaudhuri A. , Guha C. , Dutta T. K. 
Published: April 2007

AbstractHigh speed combustion characteristics of premixed stoichiometric air‐acetylene mixtures inside microchannels are numerically studied by solving a Navier‐Stokes (NS) system of equations with a single‐step chemistry model. A two dimensional explicit finite volume solver has been developed using modified advection upwind splitting methods (AUSM+) to predict the complex interactions among hydrodynamic processes, shock structures and combustion in microdimensions. The effects of channel aspect ratio and wall temperature on high speed microcombustion have been studied in this work. The increase in wall temperature due to wall friction in reduced dimensions initiates the chemical reaction of the combustible mixture near the wall region, and the reacted zone reaches the centerline for smaller height‐to‐length ratios of the microchannels. The wall temperature plays an important role in hypersonic combustion at the microscale.
Practical Assessment of Electronic Water Treatment for the Prevention of Fouling
Authors: Van Hulle S. W.H. , Vergote A. , Hogie J. , Dejans P. 
Published: April 2007

AbstractFouling or scaling, i.e., the occurrence of deposits on tubes, heat exchangers, and other devices, is a common problem in industrial and domestic processes. Many anti‐fouling techniques exist, both chemically and non‐chemically. The efficiency of non‐chemical methods is still controversial, although the use of these devices is already widespread in industry. In this contribution, a case study is presented in which the operation of such a device is demonstrated. The electronic water treatment device under study was connected to a 2 m‐long copper tube immersed in a water bath with a temperature of 65 °C. A short‐term experiment revealed that the device did not alter the water chemistry and that locally, fouling was prevented by the device. However, the potential for fouling further downstream was not reduced. A long‐term experiment further confirmed the findings of the short‐term experiment showing that locally, the device has an anti‐fouling action as a significant increase in weight was observed when the device was switched off and a significant decrease in weight was observed when the device was switched on.
A New Process for Synthesis of γ‐Butyrolactone and Cyclohexanone
Authors: Zheng H.‐Y. , Zhu Y.‐L. , Huang L. , Xiang H.‐W. , Li Y.‐W. 
Published: April 2007

AbstractA new process through the coupling of maleic anhydride hydrogenation and cyclohexanol dehydrogenation has been studied for the simultaneous synthesis of γ‐butyrolactone and cyclohexanone. The possibility of the coupling process has been investigated thermodynamically. The separated hydrogenation of maleic anhydride, the dehydrogenation of cyclohexanol, and the coupling process over the same Cu‐Zn‐Al catalyst have been carried out in a fixed‐bed reactor. Compared to conventional processes, the coupling process has several advantages, e.g., improved γ‐butyrolactone and cyclohexanone yields, good energy efficiency, and optimal hydrogen utilization. The effects of reaction temperature, n(H2)/n (reactants) and liquid hourly space velocity on the coupling process are investigated. One thousand hours of stability testing shows that the Cu‐based catalyst has relatively high activity and good stability in the coupling process.
Metal‐induced supramolecular chirality in optically active polymers of oxazoline‐substituted N‐phenylmaleimides
Authors: Xi Xiujuan , Jiang Liming , Sun Weilin , Shen Zhiquan 
Published: April 2007

AbstractPolymerization of N‐phenylmaleimide derivatives bearing a chiral oxazoline substituent at ortho‐position on the phenyl group (namely, N‐[o‐(4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenyl]maleimides, OPMI) was carried out with diethylzinc (Et2Zn) as an initiator. The resulting polymers exhibited a quite high specific rotation and a unique split‐type circular dichroism. Furthermore, an induced Cotton effect was observed in the π–π* transition region of the chromophores upon complexation of these polymers with copper(II) salt in tetrahydrofuran solution, indicating the formation of chiral supramolecular aggregates. The induced supramolecular chirality was found to be dependent on the absolute configuration of monomer units, that is, the polymers with (R)‐configurational oxazolinyl chromophores tended to form chiral aggregates with levorotatory handedness, while polymers obtained from the (S)‐monomer offered dextrogyrate one upon the addition of Cu(II) salt. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
Die Chemie der Kastanie – Experimente mit Rosskastaniensamen
Authors: Weber Philipp , Martens Andreas , Ducci Matthias 
Published: April 2007

AbstractIm vorliegenden Beitrag werden schulrelevante Experimente mit den Samen der Rosskastanie beschrieben. In einer Übersicht wird auf die Verbreitung der Rosskastanie in Mitteleuropa eingegangen und die Inhaltsstoffe der Kastaniensamen sowie historische und aktuelle Verwendungsmöglichkeiten der Kastaniensamen werden behandelt.
Spectral near‐infrared fluorescence imaging of curved surfaces using projection reconstruction algorithms
Authors: Hama Yukihiro , Koyama Yoshinori , Bernardo Marcelino , Choyke Peter L. , Kobayashi Hisataka 
Published: April 2007

AbstractIn vivo spectral fluorescence imaging has made it possible to non‐invasively visualize superficial curved structures as well as structures deep to the skin. However, the defocus created by blurring has been an obstacle to creating anatomically interpretable surface images. Herein we present a methodology to correct for blurring induced by curved structures during spectral fluorescence imaging using signal intensity projection algorithms. In a phantom and an animal model in which the lymphatic system was visualized after the interstitial injection of quantum dots with emission spectra in the near‐infrared (NIR) range, the planes of focus were sequentially adjusted to obtain a z‐stack of images which contains images acquired from multiple focal points. Maximum, minimum, median and average intensity projections were applied to the resulting images. Using the phantom, the minimum and the median intensity projection images demonstrated improved deblurring whereas during in vivo imaging the median intensity projection images more clearly visualized important structures than did the other projection techniques. Image stacking with subsequent application of appropriate projection techniques provides a simple method for deblurring in vivo optical images obtained from curved surfaces, thus improving their anatomic resolution. Copyright © 2007 John Wiley & Sons, Ltd.
The effects of intramolecular H‐bond formation on the stability constant and water exchange rate of the Gd(III)‐diethylenetriamine‐N′‐(3‐amino‐1,1‐propylenephosphonic)‐N, N,N″,N″‐tetraacetate complex
Authors: Baranyai Zsolt , Gianolio Eliana , Ramalingam Kondareddiar , Swenson Rolf , Ranganathan Ramachandran , Brücher E. , Aime Silvio 
Published: April 2007

AbstractThe binding interaction of metal chelates to biological macromolecules, though driven by properly devoted recognition synthons, may cause dramatic changes in some property associated with the coordination cage such as the thermodynamic stability or the exchange rate of the metal coordinated water. Such changes are due to electrostatic and H‐bonding interactions involving atoms of the coordination cage and atoms of the biological molecule at the binding site. To mimic this type of H‐bonding interactions, lanthanide(III) complexes with a DTPA–monophosphonate ligand bearing a propylamino moiety (H6NP–DTPA) were synthesized. Their thermodynamic stabilities and the exchange lifetime of the coordinated water molecule (for the Gd‐complex) were compared with those of the analog complexes with DTPA and the parent DTPA–monophosphonate derivative (H6P–DTPA). It was found that the intramolecular H‐bond between the ε‐amino group and the phosphonate moiety in NP–DTPA complexes causes displacements of electric charges in their coordination cage that are markedly pH dependent. In turn, this affects the characteristic properties of the coordination cage. In particular it results in a marked elongation of the exchange lifetime of the coordinated water molecule. Copyright © 2007 John Wiley & Sons, Ltd.
How to determine the number of inner‐sphere water molecules in Lanthanide(III) complexes by 17O NMR spectroscopy. A technical note
Authors: Djanashvili Kristina , Peters Joop. A. 
Published: April 2007

AbstractLanthanide(III) complexes of polyaminocarboxylates are widely used in MRI as contrast agents. The paramagnetic properties of the metal ion contribute to the increase of 1H relaxation rates, while the chelate offers a stable binding with the metal. The number of water molecules, coordinated directly to the Ln(III) ion, is very important for the relaxivity and, thus, the efficacy of these contrast agents. Here, we describe convenient methods to determine this parameter by measurement of Ln(III)‐induced shifts of the water 17O NMR resonance. Copyright © 2007 John Wiley & Sons, Ltd.
Cost‐effectiveness of influenza vaccination in working‐age cancer patients
Authors: Avritscher Elenir B. C. , Cooksley Catherine D. , Geraci Jane M. , Bekele Benjamin N. , Cantor Scott B. , Rolston Kenneth V. , Elting Linda S. 
Published: April 2007

AbstractBACKGROUND.Despite recommendations to immunize all patients at an increased risk of influenza complications, the vaccine utilization among high‐risk nonelderly adults remains low and its cost‐effectiveness is unclear. In the current study, the authors analyzed the cost‐effectiveness of influenza vaccination in working‐age (ages 20–64 years) cancer patients.METHODS.The authors developed a decision‐analytic model, from the societal perspective, using epidemiologic, vaccine effectiveness, resource utilization, cost, survival, and utility data from published sources, supplemented with data collected from the authors' own institutional accounting system. Two strategies were compared: influenza vaccination of working‐age cancer patients and no vaccination. The base‐case patient was assumed to be a 51‐year‐old cancer patient (the mean age for the National Cancer Institute's Surveillance, Epidemiology, and End Results [SEER] population of working‐age patients within 5 years of cancer diagnosis).RESULTS.The effectiveness of the influenza vaccine was 6.02 quality‐adjusted life‐years (QALYs) at a cost of $30.10. The effectiveness of the no vaccination strategy was 6.01 QALYs at a cost of $27.86. Compared with the no vaccination strategy, the incremental cost‐effectiveness ratio of vaccinating working‐age cancer patients would be $224.00 per QALY gained. Using the benchmark of $50,000 per QALY, the model was only sensitive to changes in cancer survival (threshold of 2.8 months).CONCLUSIONS.The influenza vaccine is cost‐effective for working‐age cancer patients with a life expectancy of ≥3 months. All working‐age cancer patients who are within 5 years of cancer diagnosis and have a life expectancy of at least 3 months should be vaccinated against influenza. Cancer 2007. © 2007 American Cancer Society.
Can oral supplementation with a collagen‐casein‐based liquid protein improve serum albumin levels in hemodialysis patients?
Authors: Pittaoulis Ann , Phillips Evelyn 
Published: April 2007

AbstractBACKGROUNDDecreased synthesis of albumin (Alb) results in hypoalbuminemia and occurs because of the interrelationship of inflammation and malnutrition (uremic malnutrition) observed in chronic hemodialysis (CHD) patients. Improving the nutrition status of CHD patients is necessary to prevent and treat uremic malnutrition. The issue remains of how to achieve this goal in CHD patients given the barriers to adequate and appropriate intake such as anorexia, impaired nutrient absorption, and necessary diet modifications.OBJECTIVETo determine if oral supplementation with a collagen‐casein‐based hydrolyzed liquid protein can improve Alb levels in hypoalbuminemic CHD patients.PATIENTS AND METHODSThe study patients were adult outpatients on hemodialysis for at least 1 year whose serum Alb was between 2.8 and 3.7 g/dL and who had given written consent. Patients (age = 31–90 years) were divided into 2 groups according to days they had dialysis. Controls ( n = 21; dialysis days Tuesday, Thursday, Saturday) received standard nutritional counseling. The study group ( n = 29; dialysis days Monday, Wednesday, Friday) received 30 mL of liquid protein at the beginning and end of treatment. The main outcome measures were baseline and monthly Alb for 3 months and a subjective assessment of tolerance.RESULTSFive subjects in the control group (final n = 16 [49%]) and 12 subjects in the study group (final n = 17 [51%]) did not complete the study. There was not a statistically significant correlation between baseline Alb and baseline CRP, r = − 0.30 (p = 0.093), or between baseline Alb and baseline URR, r = 0.27 (p = 0.14). Average Alb of the control group did not differ between the baseline (3.43 g/dL) and final (3.44 g/dL) measurements, t = − 0.54; df = 15; p = 0.60. In the study group, however, the final average Alb (SD) of 3.73 (0.28) was statistically significantly greater than the baseline average of 3.49 (0.20), t = − 4.19; df = 16; p = 0.001.CONCLUSIONThese statistically significant results indicate that oral supplementation with a collagen‐casein‐based hydrolyzed liquid protein can improve serum albumin levels of hypoalbuminemic CHD patients.
CNS midline cells influence the division and survival of lateral glia in the Drosophila nervous system
Authors: Kim So Hee , Kim Hyeon Ju , Kim Soo Youn , Jeon Sang‐Hak , Kim Sang Hee 
Published: April 2007

AbstractCentral nervous system (CNS) midline cells are essential for identity determination and differentiation of neurons in the Drosophila nervous system. It is not clear, however, whether CNS midline cells are also involved in the development of lateral glial cells. The roles of CNS midline cells in lateral glia development were elucidated using general markers for lateral glia, such as glial cell missing and reverse polarity, and specific enhancer trap lines labeling the longitudinal, A, B, medial cell body, peripheral, and exit glia. We found that CNS midline cells were necessary for the proper expression of glial cell missing, reverse polarity, and other lateral glia markers only during the later stages of development, suggesting that they are not required for initial identity determination. Instead, CNS midline cells appear to be necessary for proper division and survival of lateral glia. CNS midline cells were also required for proper positioning of three exit glia at the junction of segmental and intersegmental nerves, as well as some peripheral glia along motor and sensory axon pathways. This study demonstrated that CNS midline cells are extrinsically required for the proper division, migration, and survival of various classes of lateral glia from the ventral neuroectoderm. genesis 45:266–274, 2007. © 2007 Wiley‐Liss, Inc.
Synthesis and Characterisation of Polymer‐Anchored Oxidovanadium(IV) Complexes and Their Use for the Oxidation of Styrene and Cumene
Authors: Maurya Mannar R. , Kumar Umesh , Manikandan P. 
Published: April 2007

AbstractThe Schiff bases H2fsal‐ea (I), H2fsal‐pa (II) and H2fsal‐amp (III), derived from 3‐formylsalicylic acid and 2‐aminoethanol, 3‐aminopropanol and 2‐amino‐2‐methylpropanol, respectively, have been connected, by means of covalent bonds, to chloromethylated polystyrene cross‐linked with 5 % divinylbenzene. On treatment with [VO(acac)2] in dimethylformamide (DMF), these polymer‐anchored ligands PS‐H2fsal‐ea (IV), PS‐H2fsal‐pa (V) and PS‐H2fsal‐amp (VI) gave the oxidovanadium(IV) complexes, PS‐[VO(fsal‐ea)·DMF] (4), PS‐[VO(fsal‐pa)·DMF] (5) and PS‐[VO(fsal‐amp)·DMF] (6), respectively. The corresponding neat complexes [VO(fsal‐ea)]2 (1), [VO(fsal‐pa)]2 (2) and [VO(fsal‐amp)]2 (3) have also been similarly prepared. These complexes all exhibit a medium intensity band between 964 and 993 cm–1 in their IR spectra resulting from the V=O stretch. The EPR spectra of the polymer‐anchored complexes are characteristics of monomeric VIV centres with a simple S = ${1 \over 2}$ electronic spin and with an axial pattern typical of square pyramidal geometry. Broad features for the neat complexes along with magnetic susceptibility studies suggest the presence of antiferromagnetic exchange interactions between two vanadium centres in close proximity. These catalysts have been tested for the oxidation of styrene and cumene and were found to be efficient. Styrene gives five reaction products namely styrene epoxide, benzaldehyde, 1‐phenylethane‐1,2‐diol, benzoic acid and phenylacetaldehyde, whereas cumene gives acetophenone, 2‐phenylpropanal, α‐methyl styrene epoxide, 2‐phenyl‐2‐propanol, 2‐isopropyl‐1,4‐benzoquinone and α‐methyl styrene. The polymer‐anchored heterogeneous catalysts are recyclable. The catalytic activities of the neat complexes have also been examined and compared with the corresponding anchored analogues. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
A modified conservation principles theory leading to an optimal Galerkin CFD algorithm
Authors: Sahu Sunil , Baker A. J. 
Published: April 2007

AbstractA modified conservation principles theory in one, then multi‐dimensions, admits the prediction of an optimally accurate algorithm construction for the unsteady incompressible Navier–Stokes (INS) equations.Viaa time Taylor series (TS) operation, followed by a pseudo‐limit process, the theory generates a modified, but still analytical, INS system parameterized by a set of coefficients constrained only by a convexity requirement. A spatially discretized finite element implementation of a Galerkin weak statement on this modified INS system, termed the ‘Taylor weak statement (TWS), ’ generates a parameterized CFD algorithm for analysis. TWS algorithm phase velocity and amplification factor error functions are derived for linear and bilinear basis implementations assembled at the generic node. A subsequent TS expansion in wave number space admits analytical identification of parameter set options affecting lowest order error terms. The results of definitive verification‐ and validation‐class computational experiments for a range of published CFD algorithms belonging to the TWS class, reported herein, clearly confirm theoretical prediction of the optimal TWS algorithm for INS thermal/fluid transport applications. Copyright © 2007 John Wiley & Sons, Ltd.