bluuebunny/crossref_metadata_2025 huggingface dataset:
Solid-state linear polarized IR-spectroscopy of croconic and rhodizonic acids
Authors: Kolev Tsonko , Koleva Bojidarka , Spiteller Michael
Published: August 2008

The applications of linear-polarized IR-spectroscopy to oriented colloid suspensions in a nematic host are demonstrated with croconic and rhodizonic acids. The experimental IR vibrational assignments of the solid-state of both neutral compounds are presented. Assignments are supported by theoretical quantum chemical calculations and vibrational analysis at the DFT level of theoretical approximation with the 6-311++G** basis set.
Nuclear magnetic resonance spectroscopic studies of the trihexyl (tetradecyl) phosphonium chloride ionic liquid mixtures with water
Authors: Dwan Jerrod , Durant Dan , Ghandi Khashayar
Published: August 2008

Tetra-alkyl Phosphonium ionic liquids are phosphonium salts with melting points near room temperature. We report the NMR studies of water-trihexyl (tetradecyl) phosphonium chloride ionic liquid mixtures. The proton chemical shifts were used to investigate the intermolecular interactions in mixtures of ionic liquids and water. The OH chemical shifts were found to decrease as the water concentration in the ionic liquid increased, and their rate of change with temperature decreased with water concentration. The CH2 and CH3 chemical shifts were found to move downfield with the increase in temperature, and moved further downfield as water concentration was decreased. The interface of experimental data and the results of quantum calculations suggest a significant binding of phosphonium cations to chloride anion and water molecules. As well, the analysis of the data suggests a possible transformation from cationchloride-water configuration at low water concentrations to cation-water-water at higher water concentrations.
Thermodynamic and kinetic properties of scandium (I) ion reacting with SCO in gas phase
Authors: Yin Ping , Qu Rongjun , Chen Hou , Tian Yuan , Yin Gui , Bao Chongrong
Published: August 2008

Theoretical studies on the thermodynamic and kinetic properties of the reactions of scandium (I) ion with the sulfur-transfer reagent SCO via the C-O bond activation pathway have been carried out over the temperature range of 200-1200 K using the DFT/B3LYP method, general statistical thermodynamics, and Eyring transition state theory with Wigner correction. The relevant reactions include reaction 1 1Sc+ + SCO → 1IM1 → 1TS1 → 1IM2 (Step 1) → 1TS2 → 1IM3 → 1ScO+ + 1CS (Step 2), and reaction 2 3Sc+ + SCO → 3IM1 → CP → 1IM2 → 1TS2 → 1IM3 → 1ScO+ +1CS in which the spin multiplicity changes from the triplet state to the singlet state in the crossing region. It was concluded that the order of the equilibrium constants (K) and the reaction rate constants (k) are consistent with that of their corresponding exoergic energies, ΔE, and reaction barriers, respectively. Step 2 of reaction 1 is both thermodynamically and kinetically favored over the whole temperature range. Moreover, both Reaction 1 and reaction 2 are exothermic and spontaneous processes in which their entropy increases, and the magnitudes of their thermodynamic values all decrease with increasing temperature.
Consequence of hydrogen atom abstraction from 5’-hydroxyl group of 2’-deoxyadenosine. Theoretical quantum mechanics study
Authors: Karwowski Bolesław
Published: August 2008

Reactive oxygen species (ROS) may generate different nucleoside/nucleotide radicals in a cell environment. In this study, the possibility of cyclic-2’-deoxyadenosines formation by a rearrangement of their free radicals was investigated. It seems that for cyclic-nucleosides formation, adoption of an O4’-exo conformation by the sugar moiety is necessary. However, this is the energetically unfavoured form of the 2-deoxyribose ring. Moreover, the creation of a O5’, C8 bond in purine deoxy-nucleosides/nucleotides leads to the termination of the DNA elongation process.
2-(benzimidazol-2-yl)-3-hydroxychromone derivatives: spectroscopic properties and a possibile alternative intramolecular proton phototransfer
Authors: Svechkarev D. , Karpushina G. , Lukatskaya L. , Doroshenko A.
Published: August 2008

Three 2-(benzimidazol-2-yl)-3-hydroxychromone derivatives were synthesized. Their spectroscopic and fluorescent properties, due to excited state intramolecular proton transfer (ESIPT) from OH to carbonyl, were studied. Theoretical possibility of an alternative intramolecular H-bonding and experimental evidence for such behavior are discussed.
Can N-heterocyclic germylenes behave as Lewis acids - is there another side to Meller germylenes?
Authors: Kühl Olaf
Published: August 2008

N-Heterocyclic germylenes are known to exist in two structurally different forms, the planar Meller germylenes and the monoimino germylenes that feature an envelope structure. This essay reviews recent reports dealing with radical and cationic Meller type germylenes featuring the monoimino germylene structure, discusses their transformations and relationships, and asks the question whether indeed N-heterocyclic germylenes can be turned into Lewis acids.
2-pyrrolidone - capped Mn3O4 nanocrystals
Authors: Özkaya Tevhide , Baykal Abdulhadi , Toprak Muhammet
Published: August 2008

Water-soluble Mn3O4 nanocrystals have been prepared through thermal decomposition in a high temperature boiling solvent, 2-pyrrolidone. The final product was characterized with XRD, SEM, TEM, FTIR and Zeta Potential measurements. Average crystallite size was calculated as ∼15 nm using XRD peak broadening. TEM analysis revealed spherical nanoparticles with an average diameter of 14±0.4 nm. FTIR analysis indicated that 2-pyrrolidone coordinates with the Mn3O4 nanocrystals only via O from the carbonyl group, thus confining their growth and protecting their surfaces from interaction with neighboring particles.
Palladium(0)-catalyzed amination of allylic natural terpenic functionalized olefins
Authors: Houssame Soufiane , Anane Hafid , Firdoussi Larbi , Karim Abdellah
Published: August 2008

The palladium(0) catalyzed amination of allylic acetates and carbonates derivatives from terpenic olefins was carried out under mild conditions. The reaction offers a very good method for the preparation of allylic amines and thus to provide a useful entry to new functionalized terpenic olefin products. The mechanism involving a formation of p-allyl-palladium intermediate complex is in good agreement with the results obtained with the optically active substrates, as well as via an analysis of the observed regio-and stereoselectivity.
Gas-phase synthesis of inorganic fullerene-like structures and inorganic nanotubes
Authors: Deepak F. , Tenne Reshef
Published: August 2008

Following the discovery of fullerenes (C60) and carbon nanotubes, it was shown that nanoparticles of inorganic layered compounds, like WS2 and MoS2, are unstable in the planar form and they form closed cage structures with polyhedral or nanotubular shapes. Although initially the method of synthesis for the formation of such closed caged structures and nanotubes involved starting from the respective oxides, it is now well established that the gas-phase synthetic route (using metal chlorides, carbonyls etc) provides an alternative which is suitable for the synthesis of very many closed caged structures and nanotubes hitherto unknown. Various issues with this method of synthesis, including its fundamentals, mechanism, and the properties of the inorganic fullerene-like structures produced are reviewed, together with some possible applications.
Synthesis of Xenbucin using Suzuki reaction catalyzed by Pd/C in water
Authors: Kuuloja Noora , Kylmälä Tuula , Xu Youjun , Franzén Robert
Published: August 2008

Xenbucin 1, an analgesic drug, was synthesized in 4 steps using two different routes. The biaryl fragment could successfully be produced via a Pd/C catalysed Suzuki coupling in water using sodium tetraphenylborate as a phenylation reagent. Overall yields of the routes were 36% and 59%, respectively.
Sol-gel preparation and characterization of non-substituted and Sr-substituted lanthanum cobaltates
Authors: Cizauskaite Sigute , Kareiva Aivaras
Published: August 2008

This paper reports on the results concerning the sol-gel preparation and characterization of Sr-substituted perovskite lanthanum cobaltates La1−xSrxCoO3−δ (x = 0.0, 0.25, 0.5 and 0.75). The metal ions, generated by dissolving starting materials in diluted acetic acid were complexed by 1,2-ethanediol to obtain the precursors for the non-substituted and Sr-substituted LaCoO3. The influence of the synthesis temperature, heating time and the amount of substituent on the phase purity of La1−xSrxCoO3−δ were investigated. The phase transformations, composition and micro-structural features in the gels and polycrystalline samples were studied by thermal analysis (TG/DTA), infrared spectroscopy (IR), powder X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM).
Kinetic studies for the esterification of acetic acid with epichlorohydrin over an anion exchange resin catalyst
Authors: Muresan Emil , Oprea Spiridon , Hulea Vasile , Malutan Theodor , Vata Mihai
Published: August 2008

The kinetics of the esterification reaction between acetic acid and epichlorohydrin catalysed by Purolite A-520E strong basic anion exchange resin was studied. The effects of certain parameters such as stirring speed, particle diameter, temperature, catalyst amount and molar ratio between reactants were experimentally determined. It was found that the overall reaction rate is intrinsically kinetically controlled. The partial orders of reaction with respect to catalyst, acetic acid and epichlorohydrin were determined. A reaction mechanism is proposed. Based on chromatographic data and taking into account the partial orders of reaction, a more detailed kinetic model is suggested.
Preparation and characterization of alumina-zirconia composite material with different acid ratios by the sol-gel method
Authors: Ergu Ozgecan , Gürü Metin , Cabbar Canan
Published: August 2008

Alumina-zirconia composite materials were produced with different acid ratios by the sol-gel method using aluminum isopropoxide and zirconium chloride. The composites were produced by changing acid/alkoxside ratio in alumina. The composite materials were calcinated at 600°C, 900°C and 1300°C. The effects of acid concentration and calcination temperature on the surface area and pore radius were determined from the nitrogen adsorption isotherm at 77 K. The density of the composites was also measured. The minimum density of produced material was recorded as 1.35 g cm−3 at an acid/alkoxside ratio of 0.2. The highest specific surface area and pore diameter of the lightest material are 191.86 m2 g−1 and 18.4 Ǻ, respectively. Although pore diameter and specific surface area are not changed at any of the experimental temperatures which were tested by decreasing acid/alkoxside ratio, the density is slightly increased. However, it was observed that the calcination temperature significantly affects the surface area and density of the material.
Synthesis and structural peculiarities of gallium Complexes with novel paullone derivatives
Authors: Ginzinger Werner , Arion Vladimir , Giester Gerald , Galanski Markus , Keppler Bernhard
Published: August 2008

9-Bromo-7,12-dihydroindolo[3,2-d][1]benzazepin-6-ylhydrazine was reacted with 2-acetylpyridine to give a Schiff base as a potential tridentate ligand. The reaction of this ligand with gallium chloride afforded complexes of 1:1 and 2:1 stoichiometry. The results of X-ray diffraction studies of the ligand and both gallium complexes are reported and compared with the data for a related gallium complex with a Schiff base obtained from 9-bromo-7,12-dihydroindolo[3,2-d][1]benzazepin-6-ylhydrazine and 2-hydroxybenzaldehyde.
Combination of cloud point extraction and flame atomic absorption spectrometry for preconcentration and determination of trace iron in environmental and biological samples
Authors: Ghaedi Mehrorang , Shokrollahi Ardeshir , Mehrnoosh Raziyeh , Hossaini Omid , Soylak Mustafa
Published: August 2008

In the presented work, the conditions for cloud point extraction of iron from aqueous solutions using 7-iodo-8-hydroxyquinolin-5-sulphonic acid (Ferron) was investigated and optimized. The procedure is based on the separation of its ferron complex into the micellar media by adding the surfactant Triton X-114. After phase separation, the surfactant-rich phase was dissolved with 1.0 M HNO3 in methanol. Iron was determined by flame atomic absorption spectrometry. Optimization of the pH, ligand and surfactant quantities, incubation time, temperature, viscosity, sample volume, and interfering ions were investigated. The effects of the matrix ions were also examined. The detection limits for three times the standard deviations of the blank for iron was 0.4 ng m L-1, enrichment factor of 19.6 and preconcentration factor of 30 could be achieved. The validity of cloud point extraction was checked by employing real samples including soil, blood, spinach, milk, meat, liver and orange juice samples using the standard addition method, which gave satisfactory results.In the presented work, the conditions for cloud point extraction of iron from aqueous solutions using 7-iodo-8-hydroxyquinolin-5-sulphonic acid (Ferron) was investigated and optimized. The procedure is based on the separation of its ferron complex into the micellar media by adding the surfactant Triton X-114. After phase separation, the surfactant-rich phase was dissolved with 1.0 M HNO3 in methanol. Iron was determined by flame atomic absorption spectrometry. Optimization of the pH, ligand and surfactant quantities, incubation time, temperature, viscosity, sample volume, and interfering ions were investigated. The effects of the matrix ions were also examined. The detection limits for three times the standard deviations of the blank for iron was 0.4 ng m L−1, enrichment factor of 19.6 and preconcentration factor of 30 could be achieved. The validity of cloud point extraction was checked by employing real samples including soil, blood, spinach, milk, meat, liver and orange juice samples using the standard addition method, which gave satisfactory results.
Structural and dielectric studies of lead-free ceramics: Na1/2Y1/2TiO3
Authors: Barik Subrat , Choudhary Ram , Mahapatra Prasanta
Published: August 2008

The polycrystalline samples of Na1/2Y1/2TiO3 were prepared by the mixed-oxide method. A preliminary X-ray structural analysis was shown to exhibit the formation of a single-phase compound with an orthorhombic structure. Microstructural analysis by scanning electron microscopy (SEM) exhibits well defined grains distributed uniformly through out the sample suggesting the compactness and homogeneity of the sample. Detailed studies of dielectric properties of Na1/2Y1/2TiO3 in a wide frequency range (102–106 Hz) at different temperatures (31–500°C) show a dielectric anomaly at 105°C, which may be related to a ferroelectricparaelectric phase transition as suggested by hysteresis loop at room temperature. An ac conductivity (σ
ac) of the material is mainly governed by the polaron hopping mechanism, which is also influenced by both frequency and temperature. The activation energy was obtained from the plot of temperature with a.c. conductivity.
A symmetry based investigation of the band gap of SWCNTs
Authors: Pakkhesal Mehdi , Ghayour Rahim
Published: August 2008

In this paper we use symmetry of Single Walled Carbon Nanotubes (SWCNTs) to generate some types of virtual sub-bands that are lower in number than the real sub-bands obtained through conventional-TB. It is shown that the virtual sub-bands maintain the value of band gap. In obtaining the sub bands, the interactions of the nearest and the second and third-nearest neighbors are taken into account. As the consequence of lower number of sub-bands, a significant reduction in computational effort has occurred and made the approach useful.
A first-principles studies on TlX (X=P, As)
Authors: Ciftci Yasemin , Colakoglu Kemal , Deligoz Engin
Published: August 2008

We present an ab initio study of the structural, electronic and thermodynamic properties of TlX(X=P,As). The plane-wave pseudopotential approach to the density-functional theory within the LDA and GGA approximations implemented in VASP (Viena Ab-initio Simulation Package) is used. The calculated lattice parameter, elastic constants, and band structures are compared with other available theoretical results, and good agreement is obtained. In addition, we have calculated the transition pressure (P
t) from zinc-blende (ZB) to (rock-salt) NaCl structures, and have examined some thermodynamic properties.
On a current mechanism in Ta2O5 thin films
Authors: Pipinys Povilas , Rimeika Alfonsas
Published: August 2008

Electrical conduction in the temperature range of 120–370 K has been studied in sandwiched structures of Al/Ta2O5/Si. The tantalum oxide films were prepared by evaporation of tantalum on a p-Si crystal substrate, followed by oxidation at a temperature of 600°C. The temperature-dependent current-voltage (I–V) characteristics are explained on the basis of a phonon-assisted tunnelling model. The same explanation is given for I–V data measured on Ta2O5 films by other investigators. From the comparison of experimental data with theory the density of states in the interface layer is derived and the electron-phonon interaction constant is assessed.
The magnetic field dependence of the deformation potential materials in the square well confinement potential
Authors: Sug Joung , Lee Su , Kim Jong
Published: August 2008

We study the optical Quantum Transition Line Shapes (QTLS) which show the absorption power and the Quantum Transition Line Widths (QTLW) of electron-deformation potential phonon interacting systems. In order to analyze the quantum transition, we compare the magnetic field dependencies of the QTLWand the QTLS on two transition processes, namely the intra-Landau level transition process and the inter-Landau level transition process. We apply the Quantum Transport theory (QTR) to the system in the confinement of electrons by square well confinement potential. We use the projected Liouville equation method with Equilibrium Average Projection Scheme (EAPS).
Electronic properties of austenite and martensite Fe-9%Mn alloys
Authors: Uçgun Ercan , Ocak Hamza
Published: August 2008

We calculate the electronic properties of austenite and martensite Fe-9%Mn alloys using the self consistent full-potential linearized-plane-wave method under the generalized gradient approximation full lattice relaxation. By minimizing total-energy, the lattice constants in their ground states were determined. We discuss the total energy dependence of the volume, and density of states (DOS).
One-pot synthesis of xanthene derivatives under solvent-free conditions
Authors: Dabiri Minoo , Azimi Seyyedeh , Bazgir Ayoob
Published: August 2008

One-pot synthesis of aryl-14H-dibenzo[a,j]xanthene and 1,8-dioxo-octahydroxanthene derivatives using montmorillonite K10 as reusable eco-friendly catalyst under solvent-free conditions is described.
Long-term operation of a domestic wastewater treatment plant with membrane filtration
Authors: Dančová Lucia , Bodík Igor , Blšťáková Andrea , Jakubčová Zuzana , Drtil Miloslav
Published: August 2008

Possibilities of membrane technology and the use of membrane processes in wastewater treatment were investigated. The main focus was the monitoring of the starting phase of a domestic wastewater treatment plant. Experimental part of the study was realized at the municipal wastewater treatment plant (WWTP) Devínska Nová Ves — Bratislava during the period from February 2005 to September 2006. The system was stable without any external chemical treatment of the membrane modules and the permeate quality was very high. Observed decrease of COD and BOD5 values ranged between 91 % and 98 %. The process of nitrification was very successful considering its high efficiency (> 95 %).
Synthesis and biological activity of a cyclic hexapeptide from Dianthus superbus
Authors: Dahiya Rajiv
Published: August 2008

Plant-originated cyclopolypeptide (XIII) was synthesized by coupling of dipeptide Boc-l-asn(bzh)-l-phe-OH and tetrapeptide gly-l-leu-l-ala-l-tyr-OMe followed by cyclization of a linear hexapeptide segment. Structure elucidation of XIII was done on basis of detailed spectral analysis including FTIR, 1H NMR, 13C NMR, FAB MS and elemental analysis. From the results of pharmacological screening, it was concluded that XIII possesses high cytotoxic activity against DLA and EAC cell lines with CTC50 values of 15.1 μM and 18.6 μM, and potent antimicrobial activity against pathogenic fungi C. albicans with MIC of 6 μg mL−1. Moreover, XIII possesses moderate anthelmintic activity against earthworms M. konkanensis, P. corethruses, and Eudrilus sp. at 2 mg mL−1 dose level.
Infrared spectra of Hoffmann-T d-type benzene clathrates
Authors: Aytekin Meryem , Şenyel Mustafa
Published: August 2008

Six new title compounds in the form of Cd(cyclobutylamine)2M′(CN)4 · 2G (M′ = Cd or Hg; G = benzene, 1,2-dichlorobenzene, or 1,3-dichlorobenzene) have been prepared in powder form. Their spectral data were found to be consistent with the structure of the Hofmann-T d-type clathrates.
Synthesis of silsesquioxane nanocomposites
Authors: Smrtka Ondřej , Jančář Josef
Published: August 2008

In order to investigate the effect of presence of well defined nano-sized inorganic particles on the molecular mobility a conformation statistics of polymer chains, well defined polystyrene (PS) and poly(methyl methacrylate) (PMMA) macromolecules containing polyhedral oligomeric silsesquioxanes nanoparticles (POSS) were synthesized by copper-mediated atom transfer radical polymerization (ATRP). Two approaches were used for the synthesis — the first involves POSS as the initiator of ATRP; the second way considers an addition of POSS to the polymer (prepared by ATRP) with an appropriate functional group. Kinetics of polymerization was determined using common analytical methods and it was compared to the polymerizations initiated by low-molecular weight initiators, regarding the polymerization rate, initiation efficiency and polydispersity of the polymer. Efficiency of the initiation with POSS-containing initiators was low, causing remnants of inseparable free POSS in polymer. The second approach bypassed these disadvantages —POSS is connected to the polymer through a pending allyl group using the very efficient hydrosilylation reaction.
Structural and electronic effects involving pyridine rings in 4-methylpyridine Cu4OX6L4 complexes. I. Vibrational spectra of Cu4OBrnCl(6−n)(4-Mepy)4 complexes
Authors: Ondrejovič Gregor , Koman Marian , Kotočová Adela
Published: August 2008

Gaussian analysis of bands between 500 cm−1 and 600 cm−1 attributed to the $$ \tilde \nu $$ as (Cu4O) stretching vibration of the tetrahedral Cu4O core in Cu4OBrnCl(6−n)(4-Mepy)4 (n = 0–6) complexes showed two bands, symmetry reduction of the T 2 mode of vibration towards the A 1 and E modes and vibrational coupling with an R-sensitive in-plane pyridine ring bending. The Cu-O bond is considered as vibrationally coupled with the Cu-N bond and the pyridine ring through the donor-acceptor vibrational coupling and the corresponding equilibrium charge distribution. The linear correlation between $$ \tilde \nu $$ as(Cu4O) and the number of bromides in Cu4OBrnCl(6−n)(4-Mepy)4 complexes was used for the estimation of partial charges on the 4-Mepy ligands which were positive for the prevailing donors and negative for the prevailing acceptors thus evoking a π-back bonding between the Cu(II) atoms and the 4-Mepy ligands. Correlations involving selected bond lengths and bond angles in the molecular structure of the Cu4OCl6(4-Mepy)4 complex with four symmetrically independent molecules present in the unit cell indicate a symmetry reduction of the T 2 mode of vibration and the π-back bonding between the Cu(II) atoms and the 4-Mepy ligands.
Copper(II) and cobalt(II) hydroxypyridinecarboxylates: Synthesis, crystal structures, spectral and magnetic properties
Authors: Miklovič Jozef , Segľa Peter , Mikloš Dušan , Titiš Ján , Herchel Radovan , Melník Milan
Published: August 2008

Synthesis and characterization of six copper(II) and cobalt(II) octahedral complexes [M(6-OHpic)2(H2O)2] (6-OHpic is 6-hydroxypicolinato), [M(2-OHnic)2(H2O)2] (2-OHnic is 2-hydroxynicotinato), [Cu(6-OHnic)2(H2O)2] (6-OHnic is 6-hydroxynicotinato) as well as [Co(H2O)6](6-OHnic)2 are reported. Their characterization was carried out using elemental analysis, infrared, and magnetic measurements. Based on IR spectra, N,O-coordination of 6-OHpic (via the oxygen atom of the carboxyl group and the nitrogen atom of the pyridine ring), O,O-asymmetrically chelating coordination of the carboxyl groups as well as ionic coordination of 6-OHnic and chelating O,O-coordination (through the oxygen atom of the carboxyl group and the oxygen atom of the amide group) of keto(amide) tautomer of 2-OHnic were supposed. Moreover, crystal structures of 2-OHnicH and the complex [Co(2-OHnic)2(H2O)2]) were determined by X-ray single crystal structure analysis. The system of hydrogen bonds predominantly stabilizes the keto(amide) tautomer of both 2-hydroxynicotinic acid and 2-OHnic anion in the cobalt(II) complex. Intermolecular hydrogen bonds (between the oxygen atom of the amide group and the hydrogen atom of the NH group) interconnect two neighbouring molecules of 2-OHnicH forming dimers. Cobalt(II) in complex [Co(2-OHnic)2(H2O)2] has nearly a regular compressed tetragonal bipyramidal arrangement.
Computer-aided process design of affinity membrane adsorbers: a case study on antibodies capturing
Authors: Beijeren Peter , Kreis Peter , Hoffmann Achim , Mutter Martina , Sommerfeld Sven , Bäcker Werner , Górak Andrzej
Published: August 2008

Design of affinity membrane adsorbers for the purification of biomolecules requires a consideration of loading, washing, and elution. Modelling and simulation of membrane adsorbers in literature is, however, strongly focused on the loading step. Therefore, in this work, a complete process model which takes all the different steps into account was developed. Breakthrough experiments in which human IgG was captured onto and eluted from Sartobind Protein A downscale modules were used for model validation and for estimation of the required model parameters. The experimentally observed breakthrough curves were independent of the applied flow rate and from these results linear correlations between lumped kinetic parameters and linear velocity were determined. During elution, desorption was best described by an irreversible reaction of first order in H+ concentration. Applicability of the developed model to computer-aided design was illustrated through a process analysis study in which the influence of the amount of loaded protein per cycle on the process yield and productivity was investigated.
Improvement of paper strength via surface application of sugar beet pectin
Authors: Gigac Juraj , Fišerová Mária , Rosenberg Michal
Published: August 2008

The influence of surface-applied original and enzymatically-modified sugar beet pectin on strength properties of fluting, coating base paper, and core board was investigated. The effect was compared with the application of commercial strength-increasing agents. With increasing the polymer uptake, measured strength of paper increased. Original sugar beet pectin increased the strength properties of papers, at the same uptake of polymer, to a higher extent than oxidised potato starch or modified grain flour, while the effect of enzymatically-modified sugar beet pectin was the lowest. For the same increase of paper strength, a several times higher uptake of enzymatically-modified sugar beet pectin was required when compared with the original pectin, oxidised potato starch, or modified grain flour.
Pentanuclear heterobimetallic 3d-4f complexes of Ln2M3-type — structure and magnetism
Authors: Siebold Matthias , Korabik Maria , Schilde Uwe , Mrozinski Jerzy , Strauch Peter
Published: August 2008

From a series of pentanuclear, heterobimetallic complexes of the general composition [{Ln(H2O)n}2{Ni(dto)2}3] · xH2O, four complexes (Ln = Gd(III) with n = 4; Ln = Dy(III), Ho(III), or Er(III), with n = 5; x = 9–12; dto = 1,2-dithiooxalate) were studied due to their large magnetic moments (up to 14.65 B.M.). The magnetic properties of these complete series were measured at room temperature and the temperature dependent magnetic properties of the complexes Gd2Ni3, Dy2Ni3, Ho2Ni3, and Er2Ni3 were studied at room temperature down to 1.8 K. Whereas the intramolecular metal-metal distances were rather long (Ni1-Ni2: 11.0–11.5 Å; Ln-Ni: 6.0–6.3 Å), relatively short intermolecular metal-metal distances (Ni1-Ni2′: 3.5 Å; Er-Er′: 6.0 Å) were found in the crystal lattice, giving rise to weak intermolecular metal-metal interactions. These weak spin interactions were also supported by the EPR spectrum of a powdered sample of the diamagnetically undiluted Gd2Ni3 complex.
Solution properties of iron(III) complexes with 5-fluorosalicylic acid — spectra, speciation, and redox stability
Authors: Šípoš Rastislav , Šima Jozef , Tarapčík Pavol , Gyurcsik Béla
Published: August 2008

Iron(III)-5-fluorosalicylic acid systems were investigated in water by pH potentiometry combined with UV-VIS spectrophotometry. The data revealed that stable aquated mono-, bis-, and tris(5-fluorosalicylato) iron(III) complexes are formed together with their monohydroxo and dihydroxo analogues. The stability constants of all present iron(III) species were calculated. Based on pH and the metal: ligand ratio dependent distribution of the species, electronic absorption spectra of the complexes in the visible region were obtained. Redox stability was monitored as an ability to undergo both spontaneous and photoinduced reduction of iron(III) to iron(II). Complexes do not undergo any redox changes when in dark neither in methanol nor in water. While aqueous solutions of complexes are stable under the influence of incident visible radiation, steady-state irradiation of the methanolic systems by visible light led to photoreduction of iron(III) to iron(II), the quantum yield of iron(II) photoformation was determined.
Reaction of lead ions with hydroxylapatite granules
Authors: Hadioui Madjid , Sharrock Patrick , Mecherri Mohamed-Oimar , Brumas Véronique , Fiallo Marina
Published: August 2008

In the effort to improve the performance of hydroxylapatite (HA) in removing lead ions from aqueous solutions, millimeter-sized granules with 50 % porosity were synthesized. Such HA particles, after drying at 100°C, or heating at 800°C or 1100°C, exhibited the specific surface areas of 50 m2 g−1, 25 m2 g−1, and 5 m2 g−1, respectively. It was found that heavy metal sorption capacity of HAs can be related to their surface area. Non-calcined granules were difficult to handle and easy to crush. Hardened granules showed heavy metal absorption on their outer surfaces. Absorption capacity of sintered HA particles towards lead was lower but adsorbed lead ions were spread inside the porous structure of HA granules more evenly. Under flow conditions, lead ions were captured by HA at a rate of 0.5 mg g−1 min−1. Small lead phosphate aggregates were released from the HA sorbent together with calcium ions. Size of the aggregates depended on the lead concentration and ranged from 1–50 μm in diameter; the aggregates could be removed by ultrafiltration. Results show that porous hardened HA granules can be used as an efficient phosphate source for the immobilization of lead ions from aqueous media. Organic ligands tend to interfere with the water purification procedure.
L'alchimie de la compétence
Authors: Durand Thomas
Published: August 2008

L'entreprise s'efforce aujourd'hui de transformer des actifs et des ressources en profit à travers des compétences spécifiques. Elle met ainsi en œuvre une nouvelle alchimie de la compétence. Apportant des définitions claires et opérationnelles de ce concept, souvent utilisé de façon confuse dans la littérature en gestion, l'auteur propose ici un modèle de la compétence articulé autour de trois dimensions qui relèvent de la connaissance (les savoirs), des pratiques (les savoir-faire) et des attitudes (le savoir être). Et il inclut dans ce modèle non seulement les processus de management mais aussi la structure organisationnelle, la décision stratégique et l'identité.
L'apprentissage organisationnel
Authors: Kœnig Gérard
Published: August 2008

Bien que son introduction soit ancienne, l'idée d'apprentissage organisationnel fait l'objet aujourd'hui, dans une période de changements accélérés, d'un regain d'intérêt. On peut définir l'apprentissage organisationnel comme un phénomène collectif d'acquisition et d'élaboration de compétences qui, plus ou moins profondément, plus ou moins durablement, modifie la gestion des situations et les situations elles-mêmes. Dans cet article, l'auteur analyse les différents aspects de l'apprentissage organisationnel liés à cette définition avant de proposer quelques remarques de portée pratique.
De la stratégie aux processus stratégiques
Authors: Lorino Philippe , Tarondeau Jean-Claude
Published: August 2008

L'utilisation de plus en plus fréquente du terme « stratégique » dans les domaines les plus divers, par exemple dans les analyses de marketing ou de contrôle de gestion, permet de poser la question suivante : la stratégie d'entreprise est-elle en train de perdre, en tant qu'objet et outil de recherche, sa spécificité et son autonomie ? Et si tout devient stratégique, ne serait-ce pas parce que plus rien ne l'est ? Les auteurs, regrettant cette évolution qui facilite la confusion des genres, entendent ici redéfinir la stratégie et évoquer ses apports spécifiques en gestion. Notamment en proposant d'identifier la stratégie d'une entreprise par les processus qui la concrétisent.
Stratégie et pensée complexe
Authors: Martinet Alain-Charles
Published: August 2008

Pour étudier le lien entre complexité et stratégie, l'auteur convie le lecteur à un parcours en trois étapes. Il expose d'abord comment l'action et le comportement stratégiques sont générés par la complexité et impliquent donc d'en faire l'expérience pour être mis en œuvre. Il dit ensuite pourquoi une véritable pensée stratégique, apte à rendre intelligible les situations et orienter la pratique, ne peut qu'être complexe, et doit donc posséder certaines caractéristiques, qui l'éloignent notamment de la pensée managériale simplificatrice souvent à la mode ces dix dernières années. II rappelle enfin que, d'évidence, la connaissance en sciences de gestion, et particulièrement en stratégie, ne peut pas être neutre et n'a pas à l'être et qu'une pensée stratégique complexe ne doit pas craindre, bien au contraire, de s'interroger sur ses constructions et d'expliciter leur généalogie, et notamment leurs présupposés normatifs.
L'approche cognitive de la stratégie d'entreprise
Authors: Laroche Hervé , Nioche Jean-Pierre
Published: August 2008

Un nouveau courant de recherche, en matière de stratégie d'entreprise, s'appuie sur l'hypothèse suivante : l'une des clefs du processus stratégique, peut-être la seule, réside dans la pensée des dirigeants, dans ses contenus et dans ses mécanismes. C'est cette approche cognitive de la stratégie, en rapide développement aujourd'hui mais encore relativement peu connue en France, que décrivent ici les auteurs. Ils en présentent les différents aspects et ses apports, mais aussi ses limites et ses risques avant de s'interroger sur ses perspectives aussi bien théoriques que pratiques.
Expériences de consommation et marketing expérientiel
Authors: Carù Antonella , Cova Bernard
Published: August 2008

La notion d'expérience est devenue un élément-clé de compréhension du comportement du consommateur et le fondement principal d'une nouvelle démarche marketing : le marketing expérientiel. Prenant appui sur l'idée que le consommateur actuel cherche à vivre des immersions dans des expériences extraordinaires plutôt qu'à rencontrer de simples produits ou services, le marketing expérientiel prête le flanc à de sévères critiques pratiques et théoriques qui sont développées dans cet article.
Water Pollution Risk
Authors: El‐Shaarawi Abdel H.
Published: August 2008

Water pollution risk is concerned with assessing the impact of existing and future hazards that are associated with the beneficial uses of water. The focus of this article is on risks to human health due to exposure to water pollution. Some important statistical issues involved in the management of risk are discussed based on two pollution types: persistent toxic substances and microbiological contamination.
Gender, precarious work, and chronic diseases in South Korea
Authors: Kim Il‐Ho , Khang Young‐Ho , Muntaner Carles , Chun Heeran , Cho Sung‐Il
Published: August 2008

Objective

In view of the growing number of nonstandard workers in South Korea, this study examined whether nonstandard workers reported poorer health compared to standard workers and assessed whether there were gender differences in the association between employment status and chronic health outcomes.

Method

Data were taken from a representative‐weighted sample of 1,563 men and 1,045 women aged 20–64, from the 2001 National Health and Nutrition Examination Survey. Nonstandard employment included part‐time work, temporary work, and day labor. Self‐rated health and self‐reported chronic disease conditions were used as health measures.

Main Results

Nonstandard employment was significantly associated with higher risk of self‐rated health and chronic conditions after adjusting for socioeconomic position (education, occupational class, and income) and health behaviors (cigarette smoking, alcohol consumption, regular exercise, and health examinations). However, the pattern in the relation between nonstandard work and specific health problems greatly differed by gender. Among men, nonstandard work arrangements were significantly associated with musculoskeletal disorders (OR 1.97, 95% CI 1.24–3.19) and liver disease (OR 2.83, 95% CI 1.27–6.32). Among women, nonstandard employment was related to mental disorders (OR 3.25, 95% CI 1.40–7.56).

Conclusion

The findings clearly indicate the need for further study of the observed associations, particularly prospective and analytical studies. Am. J. Ind. Med. 51:748–757, 2008. Published 2008 Wiley‐Liss, Inc.
Exploring the potential of video technologies for collaboration in emergency medical care: Part I. Information sharing
Authors: Sonnenwald Diane H. , Söderholm Hanna M. , Manning James E. , Cairns Bruce , Welch Greg , Fuchs Henry
Published: August 2008

We are investigating the potential of 3D telepresence, or televideo, technology to support collaboration among geographically separated medical personnel in trauma emergency care situations. 3D telepresence technology has the potential to provide richer visual information than current 2D videoconferencing techniques. This may be of benefit in diagnosing and treating patients in emergency situations where specialized medical expertise is not locally available. The 3D telepresence technology does not yet exist, and there is a need to understand its potential before resources are spent on its development and deployment. This poses a complex challenge. How can we evaluate the potential impact of a technology within complex, dynamic work contexts when the technology does not yet exist? To address this challenge, we conducted an experiment with a posttest, between‐subjects design that takes the medical situation and context into account. In the experiment, we simulated an emergency medical situation involving practicing paramedics and physicians, collaborating remotely via two conditions: with today's 2D videoconferencing and a 3D telepresence proxy. In this article, we examine information sharing between the attending paramedic and collaborating physician. Postquestionnaire data illustrate that the information provided by the physician was perceived to be more useful by the paramedic in the 3D proxy condition than in the 2D condition; however, data pertaining to the quality of interaction and trust between the collaborating physician and paramedic show mixed results. Postinterview data help explain these results.
Exploring the potential of video technologies for collaboration in emergency medical care: Part II. Task performance
Authors: Söderholm Hanna M. , Sonnenwald Diane H. , Manning James E. , Cairns Bruce , Welch Greg , Fuchs Henry
Published: August 2008

We conducted an experiment with a posttest, between‐subjects design to evaluate the potential of emerging 3D telepresence technology to support collaboration in emergency health care. 3D telepresence technology has the potential to provide richer visual information than do current 2D video conferencing techniques. This may be of benefit in diagnosing and treating patients in emergency situations where specialized medical expertise is not locally available. The experimental design and results concerning information behavior are presented in the article “Exploring the Potential of Video Technologies for Collaboration in Emergency Medical Care: Part I. Information Sharing” (Sonnenwald et al., this issue). In this article, we explore paramedics' task performance during the experiment as they diagnosed and treated a trauma victim while working alone or in collaboration with a physician via 2D videoconferencing or via a 3D proxy. Analysis of paramedics' task performance shows that paramedics working with a physician via a 3D proxy performed the fewest harmful interventions and showed the least variation in task performance time. Paramedics in the 3D proxy condition also reported the highest levels of self‐efficacy. Interview data confirm these statistical results. Overall, the results indicate that 3D telepresence technology has the potential to improve paramedics' performance of complex medical tasks and improve emergency trauma health care if designed and implemented appropriately.
Robust tracking problem for continuous time stochastic uncertain systems
Authors: Yoon Myung‐Gon , Ugrinovskii Valery A.
Published: August 2008

We propose a finite‐horizon robust minimax tracking controller design method for time‐varying continuous time stochastic uncertain systems. The uncertainty in the system is characterized by a set of probability measures under which stochastic noises, driving the system, are defined. A minimax optimal tracking controller is derived from the solution of a risk‐sensitive linear quadratic Gaussian control problem. Also a numerical example is presented to illustrate the characteristics of proposed tracking controller. Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Sliding‐mode control of a three‐degrees‐of‐freedom nanopositioner
Authors: Shen Jing‐Chung , Jywe Wen‐Yuh , Liu Chien‐Hung , Jian Yu‐Te , Yang Jeffrey
Published: August 2008

This paper presents the sliding‐mode control of a three‐degrees‐of‐freedom nanopositioner (Z, θx, θy). This nanopositioner is actuated by piezoelectric actuators. Capacitive gap sensors are used for position feedback. In order to design the feedback controller, the open‐loop characteristics of this nanopositioner are investigated. Based on the results of the investigation, each pair of piezoelectric actuators and corresponding gap sensors is treated as an independent system and modeled as a first‐order linear model coupled with hysteresis. When the model is identified and the hysteresis nonlinearity is linearized, a linear system model with uncertainty is used to design the controller. When designing the controller, the sliding‐mode disturbance (uncertainty) estimation and compensation scheme is used. The structure of the proposed controller is similar to that of a proportional integral derivative controller. Thus, it can be easily implemented. Experimental results show that 3‐nm tracking resolution can be obtained. Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Incidence and predictors of delayed chronic kidney disease in long‐term survivors of hematopoietic cell transplantation
Authors: Choi Michael , Sun Can‐Lan , Kurian Seira , Carter Andrea , Francisco Liton , Forman Stephen J , Bhatia Smita
Published: August 2008

BACKGROUND.

The authors investigated the risk of delayed chronic kidney disease (CKD) in 1190 adult hematopoietic cell transplantation (HCT) survivors who underwent HCT for hematologic malignancies or aplastic anemia between 1976 and 1997 and survived for at least 1 year.

METHODS.

CKD was defined as a sustained elevation of serum creatinine that indicated a glomerular filtration rate of <60 mL per minute per 1.73 m2for ≥3 months. The median age at HCT was 35 years (range, 18.1‐68.6 years), and the median length of follow‐up was 7.1 years after HCT (range, 1‐24.3 years).

RESULTS.

Sixty patients with CKD were identified, resulting in a cumulative incidence of 4.4% at 5 years (autologous HCT, 3.8%; matched‐sibling HCT, 4.5%; unrelated donor HCT, 10%;P= .09 compared with autologous HCT). Older age at HCT (relative risk [RR] per 5‐year increment, 1.33; 95% confidence interval [CI], 1.2‐1.5), exposure to cyclosporine without tacrolimus (RR, 1.90; 95% CI, 1.1‐3.4) or with tacrolimus (RR, 4.59; 95% CI, 1.8‐11.5), and a primary diagnosis of multiple myeloma (RR, 2.51; 95% CI, 1.1‐5.6) were associated with an increased risk of delayed CKD.

CONCLUSIONS.

In this study, the authors identified a subpopulation of patients who underwent HCT and remained at increased risk for CKD. The current findings set the stage for appropriate long‐term follow‐up of vulnerable patients. Cancer 2008. © 2008 American Cancer Society.
Copy number gains in EGFR and copy number losses in PTEN are common events in osteosarcoma tumors
Authors: Freeman Serena S. , Allen Steven W. , Ganti Ramapriya , Wu Jianrong , Ma Jing , Su Xiaoping , Neale Geoff , Dome Jeffrey S. , Daw Najat C. , Khoury Joseph D.
Published: August 2008

BACKGROUND.

Osteosarcoma cell lines and tumors have been shown to express epidermal growth factor receptor (EGFR) and harbor amplifications at the EGFR locus. In this study, the authors further analyzed the genomic features of EGFR in osteosarcoma tumors and investigated whether they correlate with phosphatase and tensin homolog (PTEN) expression and copy number status.

METHODS.

EGFR and PTEN expression was assessed by immunohistochemistry (n = 28), and copy number alterations at the EGFR and PTEN loci were surveyed using Affymetrix (Santa Clara, Calif) 50K single nucleotide polymorphism (SNP) arrays (n = 31) and fluorescence in situ hybridization (FISH) (n = 27). The EGFR tyrosine kinase domain was sequenced to survey for activating mutations (n = 34). In addition, EGFRvIII expression was assessed using reverse transcriptase polymerase chain reaction (n = 24). Results were correlated with available clinical information on 59 patients, with a median age of 14.1 years (range, 5‐23years) and median follow‐up of 4.4 years.

RESULTS.

EGFR expression was detected in the majority of osteosarcoma tumors surveyed (23 of 28; 82%). SNP arrays revealed evidence of frequent copy number gains at 7p11.2 and losses at 10q23.21. A sizeable subset (16 of 27 cases; 59%) showed gains at the EGFR locus using FISH (amplification in 4 of 27 [15%] and balanced chromosome 7 polysomy in 12 of 27 [44%]), and 12 cases showed deletions at the PTEN locus (biallelic deletions in 4 of 27 [15%] and monoallelic deletion in 9 of 27 [33%]). No activating mutations in the EGFR tyrosine kinase domain, EGFRvIII expression, or association with clinical findings were detected.

CONCLUSIONS.

EGFR expression and genomic gains at the EGFR locus are prevalent in osteosarcoma tumors, which also commonly harbor deletions at the PTEN locus. Cancer 2008. © 2008 American Cancer Society.