bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure Analysis of Reaction Intermediates in Metal Substitution Reactions in Solution by the Stopped-Flow EXAFS Method
Authors: Ozutsumi Kazuhiko , Ohtaki Hitoshi
Published: December 2004

Improvements of XAFS (X-Ray Absorption Fine Structure) measurements in the time domain are summarized and several examples of structure determination of reaction intermediates by the EXAFS (Extended X-Ray Absorption Fine Structure) method are given. The local structure around the copper(II) or cobalt(II) ion is described in the reaction intermediate in the metal substitution reaction of the homodinuclear mercury(II) porphyrinato (5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin; H6tpps) complex in an acetate buffer determined by the stopped-flow EXAFS (SF-EXAFS) method, which was developed by us. Comparison of the bond lengths in the intermediates with those in the reactants and the products of the metal substitution reaction, the structure of which has been determined by the same method, revealed the cause of the instability of the reaction intermediates.
Structural Genealogy of BEDT-TTF-Based Organic Conductors III. Twisted Molecules: δ and α′ Phases
Authors: Mori Takehiko
Published: December 2004

δ-phase (β-PF6 type) BEDT-TTF (bis(ethylenedithio)tetrathiafulvalene)-based organic conductors are characterized by the twisted overlap mode in the stack. Since the twisted mode has large intermolecular orbital overlap, the δ-phase is regarded as a twisted dimer structure. This type of overlap is, however, insensitive to small changes of the structure. On the contrary, an oblique interaction alters the warping of the open Fermi surface, to control the metal-insulator transition temperature, TMI. Through the change of this oblique interaction, TMI is scaled by the axis ratio for a family of salts with the same stacking pattern. As a general summary of BEDT-TTF salts, an empirical rule is proposed to predict, from the number of crystallographically independent molecules, whether an insulating state of BEDT-TTF salts will be paramagnetic or nonmagnetic. This rule is based on hypothetical pair formation of spins located on each dimer, and universally applies to all BEDT-TTF salts. This rule is extended to metallic salts, and among the potentially nonmagnetic salts, a dimerized dimer structure is the necessary condition of superconductivity. The potentially paramagnetic superconductors have strongly dimerized structures like β and κ phases. From this we can make a reasonable prediction as to superconducting phases.
Analysis of 109Ag MAS NMR Chemical Shieldings Observed in AgxCu1−xI Crystals
Authors: Ida Tomonori , Endo Kazunaka , Suhara Masahiko , Kenmotsu Motoko , Honda Kenji , Kitagawa Susumu , Kawabe Hiroyuki
Published: December 2004

109Ag NMR signals in AgxCu1−xI crystals were shifted to a low field relative to that in solid AgI with decreasing the unit cell constant analogously to 63Cu MAS NMR signals reported in a previous study. The observed chemical shieldings were analysed using the results of Ag and Cu NMR shielding calculations of tetrahedral (Td) MI43− (M = Ag, Cu) complex ions with the ab initio GAUSSIAN 94 program using a double-ζ basis set for the Ag, Cu, and I atoms. Since the shift is explained dominantly by the paramagnetic shielding term, which depends on the d-hole and p-electron densities in Ag or Cu atoms for the MI43− complex ions, the observed 109Ag shift moved to a low field with decreasing the lattice constant, corresponding to an increase in the d-hole and p-electron densities for AgI43− (RAg–I = 2.68, 2.73, 2.77 Å) relative to the AgI43− (RAg–I = 2.81Å) ion.
[3 + 2] Cycloaddition of Allylic Silane with N-Chlorosulfonyl Isocyanate
Authors: Isaka Masahiko , Williard Paul G , Nakamura Eiichi
Published: December 2004

Reaction of a substituted allylsilane with N-chlorosulfonyl isocyanate at 0 °C takes place in an unexpected manner to give a [3 + 2] cycloaddition product, a β-silyl-γ-lactam, rather than a [2 + 2] cycloadduct.
Calcined Layered Double Hydroxides as Basic Heterogeneous Catalysts for the Oppenauer Oxidation of Alcohols
Authors: Raja Thirumalaiswamy , Jyothi T M , Sreekumar K , Talawar M B , Santhanalakshmi J , Rao B S
Published: December 2004

The oxidation of various alcohols with a ketone was carried out over a series of calcined layered double hydroxides, producing corresponding ketones in a batch reaction system. From the observed results it was found that the layered double hydroxide, MgII–AlIII (4:1) ratio), calcined in air at 723 K efficiently oxidize alcohols compared with other LDHs.
Preparation and Characterization of Novel Carbosilane Dendrimers Carrying Mesogens
Authors: Terunuma Daiyo , Kato Tomonori , Nishio Rei , Aoki Yoshio , Nohira Hiroyuki , Matsuoka Kouji , Kuzuhara Hiroyoshi
Published: December 2004

A series of new carbosilane dendrimers carrying cyanobiphenyl derivatives was prepared starting from the tertiary core molecule, triallylphenylsilane. The phase transition of the dendrimers depends on the dendrimer generation, and the spacer lengths were investigated by using differential scanning calorimetry (DSC) and an optical polarizing microscope. All of the dendrimers prepared exhibited smectic A phases. The phase behavior on the phase-transition pattern of the DSC curve and the texture appearances of G2-mesogen(5) carrying twenty-seven mesogens were observed to be similar to that of the reported G2 dendrimer prepared starting from the quarternary core molecule, tetraallylsilane, carrying thirty-six mesogens.
Formation of Pyruvaldehyde (2-Oxopropanal) by Oxidative Dehydrogenation of Hydroxyacetone
Authors: Ai Mamoru , Ohdan Kyoji
Published: December 2004

Various mixed oxides were tested as catalysts for oxidative dehydrogenation of hydroxyacetone to form pyruvaldehyde (2-oxopropanal). The best results were obtained from an iron phosphate with a P/Fe atomic ratio of 1.05. The yield of pyruvaldehyde reached 88%. The next best results were obtained from a supported heteropoly acid (H3PMo12O40). The other molybdenum- and vanadium-based oxide catalysts were not suitable. The effects of the composition and structure of iron phosphate and the effects of reaction variables on the formation of pyruvaldehyde were also studied.
“Syn-Effect” in the Conversion of (E)-α,β-Unsaturated Esters into the Corresponding β,γ-Unsaturated Esters and Aldehydes into Silyl Enol Ethers
Authors: Guha Samar Kumar , Shibayama Atsushi , Abe Daisuke , Sakaguchi Maki , Ukaji Yutaka , Inomata Katsuhiko
Published: December 2004

The stereochemistry in the conversion of (E)-α,β-unsaturated esters into the corresponding β,γ-unsaturated esters, and that in the conversion of aldehydes into the silyl enol ethers, were investigated. The Z/E ratios of the resulting β,γ-unsaturated esters and the silyl enol ethers varied according to the γ-substituents of the (E)-α,β-unsaturated esters and the α-substituents of the aldehydes, respectively. This phenomenon was rationalized by a “syn-effect”, which may be attributed primarily to a σ → π* interaction and/or 6π-electron homoaromaticity.
Two-Dimensional 1H Spin-Exchange NMR Study of Molecular Arrangements in Diphenylhexatrienes
Authors: Hayashi Shigenobu , Sonoda Yoriko
Published: December 2004

Molecular arrangements in crystalline solids of p,p′-disubstituted (1E,3E,5E)-1,6-diphenyl-1,3,5-hexatrienes (DPHs) have been studied by two-dimensional 1H spin-exchange NMR. The mixing time dependence of the cross peak intensity has been analyzed, and the time constants representing proton spin exchange rates have been estimated. Data for methoxy derivative 1 demonstrate the presence of intermolecular spin exchange between triene protons and methoxy protons; thus one may conclude that a methoxy group is located close to a hexatriene chain of an adjacent molecule. On the other hand, there is no evidence of intermolecular spin exchange for formyl derivative 2.
Bond-Length Equalization and Aromaticity in Charged π-Systems
Authors: Aihara Jun-ichi
Published: December 2004

The conventional interpretation of bond-length equalization gives a misleading picture of the aromaticity on charged π-systems. A charged π-system in general is reluctant to undergo marked bond-length alternation, even if it is antiaromatic with a negative topological resonance energy. The pentalene dication and the C60 decacation are antiaromatic with a modest distortion of the molecular skeleton. Small maximum eigenvalues of the bond–bond polarizability matrices support the absence of second-order double-bond fixation in many charged antiaromatic π-systems.
Kinetics on Isomeric Alcohols Recognition by α- and β-Cyclodextrins Using Ultrasonic Relaxation Method
Authors: Fukahori Takanori , Nishikawa Sadakatsu , Yamaguchi Kyohei
Published: December 2004

Ultrasonic absorption method was applied to elucidate the dynamic properties of host–guest complexation between α-cyclodextrin or β-cyclodextrin (host) and butanol isomers (guest) at 25 °C. The aim of this work was to reveal the effect of a structural difference in the hydrophobic part of a guest on the kinetic parameters for an inclusion reaction with cyclodextrins. Moreover, it was expected to clarify the effect of the cavity size on the reaction. Only when the host and guest existed together in water, a clear single relaxational phenomenon was observed. The cause of the relaxation was responsible for the complexation reaction between the host and the guest. The rate and equilibrium constants were obtained from the concentration dependence of the relaxation frequency, and the standard volume changes of the complexation reaction were from the maximum absorption per wavelength. The backward rate constant, kb, was very dependent on the structure of the guest molecule. The kb value decreased in the next hydrophobic series, nor- < sec- < tert- in β-CD systems, although a smaller kb value was observed when the guest possessed a normal carbon chain in α-CD systems. The results of the volume change of the reaction implied that α-CD could only include a guest quite shallowly, and almost the entire guest molecule was included into the β-CD cavity.
Synthesis and Characterization of Polynuclear Chain and Tetranuclear Complexes of Mixed-Valent Ruthenium(II,III) Pivalate with N,N′-Didentate Ligands
Authors: Yoshioka Daisuke , Mikuriya Masahiro , Handa Makoto
Published: December 2004

Polymeric chain complexes, [Ru2(piv)4(pyz)]n(BF4)n·3nH2O (1), [Ru2(piv)4(4,4′-bpy)]n(BF4)n·nH2O (2), [Ru2(piv)4(dabco)]n(BF4)n·2nH2O (3), [Ru2(piv)4(phz)]n(BF4)n (4), and [Ru2(piv)4(H2O)2(tmpyz)]n(BF4)n·nCH2Cl2 (6), (Hpiv = pivalic acid, pyz = pyrazine, 4,4′-bpy = 4,4′-bipyridine, dabco = 1,4-diazabicyclo[2.2.2]octane, phz = phenazine, and tmpyz = tetramethylpyrazine), were synthesized and characterized by elementary analyses, infrared and electronic spectroscopies, and variable-temperature magnetic susceptibilities (4.5–300 K). A tetranuclear complex, [{Ru2(piv)4(H2O)}2(phz)](BF4)2 (5), was also synthesized, and a “dimer of dimers” structure was confirmed by an X-ray structure analysis. The crystal structure of 6 shows that [Ru2(piv)4(H2O)2]+ units are linked by hydrogen bonds with tmpyz molecules, giving zigzag chains with Ru1–O5···N1 angle of 108.1(2)°. A red-shift of the δ*/π*(Ru2) → σ*(Ru–O), and δ(Ru2) → δ*(Ru2) transition bands of the RuII,III2 core was observed in polymeric chain adducts 1–4. All of the present complexes show a very weak antiferromagnetic interaction between the dinuclear units with a considerable zero-field splitting parameter.
Optimal Environment for Maximal Molecular Recognition against Temperature. Three Distinct Patterns in Temperature–Recognition Profiles as a Function of Composition of Aqueous Binary Solvents
Authors: Endo Tadashi , Sugio Keitaro , Kogure Sadahiro , Horikosi Suguru , Tojima Motohiro , Aono Yosihiro , Ito Masato M
Published: December 2004

Oxidation of a pair of associating thiols 1 and 2, each having a binding site [–C(=O)NHC(=O)NH–] and a recognition site (R1 or R2), is examined at various temperatures as a function of mole fraction of water (xw) in aqueous binary solvents with EtOH, CH3CN, and i-PrOH. The selectivity (r) — a measure of the degree of molecular recognition in the oxidation — is represented by the logarithmic ratio of the yield of the unsymmetrical disulfide 4 to twice that of the symmetrical one 3. It is found that three distinct patterns are present in temperature–recognition profiles, depending on composition of the aqueous binary solvents: (1) “progressive decrease” in the lower xw region; (2) “presence of a maximum” in the medium xw region; (3) “progressive increase” in the higher xw region. It is also clarified that aqueous mixed solvents in the medium xw region are indispensable for maximal recognition to occur against temperature (the presence of a maximum in the temperature–selectivity relationship). Dependence of the r on the xw at lower and higher temperatures, presence of three distinct patterns in the temperature–recognition profiles, and so on are discussed in relation to the maximal recognition.
Selective Oxidative Carbonylation of Amines to Oxamides and Ureas Catalyzed by Palladium Complexes
Authors: Hiwatari Kozo , Kayaki Yoshihito , Okita Koshi , Ukai Tomohiro , Shimizu Isao , Yamamoto Akio
Published: December 2004

A new process for converting secondary amines into N,N,N′,N′-tetraalkyloxamides under CO pressure, catalyzed by homogeneous palladium complexes in the presence of 1,4-dichloro-2-butene (DCB) as an oxidant, has been developed. The mechanism of the oxidative double-carbonylation process, consisting of the oxidation of Pd(0) to Pd(II) with DCB through a β-chloride elimination of the η3-(chloromethyl)allylpalladium(II) intermediate, the formation of mono- and bis(carbamoyl)palladium species, and a reductive elimination of the two carbamoyl ligands, is proposed based on studies of the behavior of carbamoylpalladium complexes. When primary amines are employed with DCB as the oxidant, N,N′-dialkyloxamide is catalytically produced, whereas urea is exclusively produced when iodine is used as the oxidant. The reaction of an N-monopropylcarbamoylpalladium complex with propylamine under CO gave N,N′-dipropylurea, whereas a treatment with diethylamine yielded unsymmetrical N,N-diethyl-N′-propylurea, implying the intermediate formation of propyl isocyanate that is converted into the urea upon a reaction with the added amine. A kinetic study on the reaction of chloro-N-propylcarbamoylpalladium with triethylamine suggested a process proceeding through a base-promoted deprotonation of the N-monoalkylcarbamoyl ligand to form propyl isocyanate.
Synthesis of Chroman Derivatives by the Ring Expansion Reaction of Spirodienones, and an Assessment of their Plant Growth Inhibition
Authors: Doi Fuminao , Ohara Taiga , Ogamino Takahisa , Higashinakasu Keiko , Hasegawa Koji , Nishiyama Shigeru
Published: December 2004

Lewis acid-promoted 1,2-shift rearrangement reactions of the spirodienones, generated by the anodic oxidation of phenol derivatives, provided corresponding chromans. In addition to steric repulsion, electron-donating or withdrawing characteristics of the arylic substituents controlled the direction of the rearrangements. The plant growth inhibitory activity of several chroman derivatives was evaluated. In contrast to apparent inhibitions of 21c and 22c against both cress and oat, the selective activity against coleoptile and root of oat was observed in 21a, 21b, and 22d. Interestingly, the regioisomer 22b of 21b showed no activity.
A New Route to 2,4,6-Trisubstituted-6H-1,3-Oxazines
Authors: Kidwai Mazaahir , Thakur Ruby , Mohan Richa
Published: December 2004

The Lewis acid (borontrifluoride etherate) catalyzed novel synthesis of 2,4,6-trisubstituted-6H-1,3-oxazines is described here. Also, a new route towards an environmentally benign synthesis of the title compounds has been developed using montmorillonite K-10 clay as a catalyst under microwave irradiation (MWI). The procedure replaces the Lewis acid, and the products are obtained in a high yield and shorter reaction time.
Halide-Bridged Zigzag Chain of Tetrakis(acetamidato)dirhodium Cationic Radical Assisted by Hydrogen Bond
Authors: Yang Zhiyong , Fujinami Tomoharu , Ebihara Masahiro , Nakajima Kiyohiko , Kitagawa Hiroshi , Kawamura Takashi
Published: December 2004

The reaction of a Rh25+ cationic radical salt, 2,2-cis-[Rh2(acam)4(H2O)2]ClO4 (Hacam = acetamide), with sodium halides in aqueous solution gave crystals of [Rh2(acam)4Cl]n·7nH2O and [Rh2(acam)4Br]n, both of which consist of zigzag chain of (–Rh–Rh–X–)n, which is supported by hydrogen bond between amidato–NH and amidato–O atoms for the chain of the bromide and between O atoms of amidato bridges through interstitial water molecules for the chloride chain.
Synthesis of AlPO4-5 and AlPO4-11 Molecular Sieves by Dry-Gel Conversion Method
Authors: Bandyopadhyay Mahuya , Bandyopadhyay Rajib , Kubota Yoshihiro , Sugi Yoshihiro
Published: December 2004

Synthesis of aluminophosphate molecular sieves AlPO4-5 and AlPO4-11 has been studied by dry-gel conversion method using triethylamine and dipropylamine as structure-directing agents (SDAs), respectively. Amount of SDAs and the bulk water as the source of steam played vital roles during the crystallization. SAPO counterparts of the AlPO4’s were also synthesized by this method.
Electrochemical Detection of Base Pair Mutation
Authors: Yamashita Kenichi , Takagi Makoto , Kondo Hiroki , Takenaka Shigeori
Published: December 2004

An electrochemical method for detecting base pair mutation was devised, which is based on higher affinity of ferrocenyl naphthalene diimide intercalator for (matched) DNA duplex than for (mismatched) single stranded DNA on the electrode surface.
Potential of Zero Charge of a Molybdenum Electrode by Laser Ablation Voltammetry
Authors: Nakamura Kiyoshi , Ohno Masashi , Umemoto Kisaburo , Hinoue Teruo
Published: December 2004

We found that a zero-current potential, ZCP, in the laser ablation voltammogram agreed with a potential at which a differential capacitance component showed a minimum in the corresponding phase-selective ac voltammogram at the Mo electrode in phosphate buffer. This fact suggests that the ZCP is identical with the potential of zero charge (pzc). A pH dependence of the ZCP for the Mo electrode is discussed in terms of specific adsorption of a hydroxide ion.
A High Thermal Stable Light-Emitting Complex Based on a Tridentate Ligand
Authors: Shao Yan , Qiu Yong , Hu Xiaoming , Hong Xiaoying
Published: December 2004

A new complex with a tridentate ligand, (salicylidene-o-aminophenolato)(8-quinolinoato)aluminum (Al(Saph-q)), bearing a high glass transition temperature of 226 °C, shows a strong potential as a stable light-emitting material for organic electroluminescence.
A New and Efficient Method for Oxidation of Various Alcohols by Using N-tert-Butyl Phenylsulfinimidoyl Chloride
Authors: Mukaiyama Teruaki , Matsuo Jun-ichi , Yanagisawa Manabu
Published: December 2004

Various primary and secondary alcohols were smoothly oxidized to afford the corresponding aldehydes and ketones in excellent yields by using N-tert-butyl phenylsulfinimidoyl chloride (1) in the presence of DBU (1,8-diazabicyclo[5.4.0]undec-7-ene). The oxidation of alcohols was carried out in a simple manner by using the isolable oxidizing agent 1 under basic conditions.
Photochemical Bahavior of Zinc(II) Tetraphenylporphyrin in Nanoscale-fibers Made of trans-1,2-Bis(alkylamide)cyclohexane Derivatives
Authors: Kimura Matsumi , Kitamura Takuya , Muto Tsuyoshi , Hanabusa Kenji , Shirai Hirofusa , Kobayashi Nagao
Published: December 2004

A zinc porphyrin dimer, in which two porphyrin moieties were linked with an optically active (1R,2R)-trans-1,2-bis(aklylamide)cyclohexane unit, was incorporated into nanoscale fibers made of organogelators and the fluorescence quenching of zinc porphyrin moieties was diminished by the incorporation.
Control of the Photoisomerization Mode of Carbon–Carbon Double Bond by Intramolecular Hydrogen Bond; One-way Photoisomerization of 2′-Hydroxychalcone Induced by Adiabatic Intramolecular Hydrogen Atom Transfer
Authors: Norikane Yasuo , Itoh Hiroki , Arai Tatsuo
Published: December 2004

To investigate the effect of intramolecular hydrogen bonding on the photoisomerization of carbon–carbon double bond, photoisomerization of 2′-hydroxychalcone has been studied. Based on the quantum yield measurements and laser flash photolysis studies, it was found that 2′-hydroxychalcone isomerized only from cis- to trans-isomer. The one-way cis-trans isomerization is induced by the adiabatic hydrogen atom tranfer in the triplet state.
The Mild Hydrothermal Synthesis of Complex Fluorides of AZnF3 (A = Na, K)
Authors: Li Hong , Jia Zhihong , Shi Chunshan
Published: December 2004

The complex fluorides of AZnF3 (A = Na, K), which are isostructural with perovskite phases were obtained by the method of hydrothermal synthesis at 160–220 °C. Compared with traditional high-temperature solid-state method, the products were pure and contained lower amount of oxygen.
Preparation and Characterization of Mono-Imidazole Ligated (meso-Tetramesitylporphyrinato)iron(III) Complexes: Model for Cytochromes c’
Authors: Ikezaki Akira , Nakamura Mikio
Published: December 2004

A series of mono-imidazole ligated (meso-tetramesitylporphyrinato)iron(III) complexes have been prepared. The spin states of these complexes are presented as the admixed intermediate (S = 3/2, 5/2) on the basis of the 1H NMR, 13C NMR, EPR, and magnetic moments. The S = 3/2 character has increased as the axial imidazole ligand becomes bulkier.
Actinide chemistry: from weapons to remediation to stewardship
Authors: Choppin Gregory R.
Published: December 2004

An integral part of the international conferences on the Chemistry and Migration of Actinides has been the separation science of these elements. Separations involving actinide elements began with the discovery of radioactivity when Crookes reported that addition of carbonate ions to a solution of uranium caused formation of a soluble uranium carbonate complex and of a precipitate which contained most of theβ,γradioactivity. Subsequently, the Curies separated components of pitchblend to isolate the different radioactive elements which led, in 1898, to the discovery of the new element, polonium. The separation method used by these pioneers was precipitation which remained the dominant separation technique for the first 40 years of actinide research. This paper reviews actinide separation science to the present time.
Solubility and colloid formation of Th(IV) in concentrated NaCl and MgCl2solution
Authors: Altmaier M. , Neck Volker , Fanghänel Thomas
Published: December 2004

The solubility of crystalline ThO2(cr) and amorphous hydrated Th(IV) oxyhydroxide ThOn(OH)4-2n·xH2O(am) has been measured in dilute to concentrated NaCl and MgCl2solutions equilibrated with magnesium hydroxide or hydroxychloride at 22±2 °C. The contributions of colloids to the total thorium concentrations observed in both over- and undersaturation experiments with amorphous Th(IV) precipitates have been analysed by ultracentrifugation. The solubility increasing effect of long-time stable Th(IV) eigencolloids, previously investigated in 0.5 M NaCl solutions, is also observed in concentrated 5 M NaCl. Ionic strength and chloride concentration have no effect on the stability of these hydrophilic Th(IV) oxyhydroxide eigencolloids, which are the predominant species in solution. They cause relatively high total thorium concentration in neutral to alkaline steady state solutions, independent of ionic strength: log[Th]tot≈log[Th]coll=-6.3±0.5. In concentrated MgCl2solutions saturated with magnesium hydroxychloride colloids, the formation of pseudocolloids,i.e., Th(IV) sorbed onto Mg2(OH)3Cl·4H2O(coll), leads to a further increase of the total thorium concentration up to 10-5M. The present results are discussed with regard to maximum Th(IV) and Pu(IV) concentrations in performance assessment calculations.
On Mo-Ru-Tc-Pd-Rh-Te alloy particles extracted from spent fuel and their leaching behavior under Ar and H2 atmospheres
Authors: Cui Daqing , Low Jeanett , Sjöstedt Cecilia J. , Spahiu Kastriot
Published: December 2004

In the present work, we extracted Mo-Tc-Ru-Pd-Rh-Te alloy particles from spent fuel by a non-oxidative selective leaching of the fuel matrix, characterized them and studied their leaching behavior under different redox conditions. After selecting the optimal experimental conditions by using a synthetic alloy, the radioactive alloy particles were extracted from spent fuel and characterized by using SEM (scanning electron microscopy)-WDS (wavelength dispersive spectra). Micrometer sized alloy particles display very similar compositions, on average (wt.%): 32.7% Mo, 40.5% Ru, 7% Tc, 4.4% Rh, 12.2% Pd and 3.8% Te. The alloy particles were leached in 10 mM NaCl and 2 mM NaHCO3 solutions, purged with two kinds of gas mixtures. It was observed that, under purging with Ar + 0.03% CO2, the leaching rates of 99Tc and 100Mo were similar, about 1.5 ppb/day. The results obtained under purging with 89.97% Ar + 0.03% CO2 + 10% H2 indicate that the 4d alloy particles are very effective catalysts for reduction caused by hydrogen: the concentrations of 99Tc and 100Mo dropped to levels below 1 ppb. No significant leaching of Ru, Rh, Pd and Te was observed during purging with both gas mixtures.
Application of the NICA-Donnan model for proton, copper and uranyl binding to humic acid
Authors: Saito Takumi , Nagasaki S. , Tanaka S. , Koopal L. K.
Published: December 2004

Humic acids are natural organic materials that play an important role in the migration of heavy metal and actinide ions in aquatic and soil systems. In the present study, the binding of protons, copper ions and uranyl ions to the purified Aldrich humic acid (PAHA) is investigated and the results are modeled with the Non-Ideal Competitive Adsorption (NICA) model extended with electrostatic interactions according to the Donnan model (NICA-Donnan model). The NICA part of the model enables one to describe the competitive ion binding to a heterogeneous substrate taking into account a different stoichiometry per ion. The NICA-Donnan model can describe the binding of the ions to PAHA in large concentration ranges (3<pH<11; 3<pCu<13; 4<pUO2<18) and over a wide range of environmental conditions (pH, ionic strength). From the model description it follows that the affinity distribution of PAHA is bimodal with about equal numbers of "carboxylic"- (low logKH) and "phenolic"-type (high logKH) sites. The stoichiometry parameters of the binding reactions for copper and uranyl indicate both mono- and bi-dentate binding. Some specific attention is paid to the distribution of the bound uranyl ions over the "carboxylic" and "phenolic"-type sites. Such information is useful for comparison with spectroscopic information on the binding.
The redox behaviour of plutonium in humic rich groundwater
Authors: Marquardt Christian M. , Seibert A. , Artinger Robert , Denecke Melissa A. , Kuczewski B. , Schild D. , Fanghänel Thomas
Published: December 2004

Experiments with different oxidation states of Pu in GoHy-532 groundwater under reducing conditions reveal that Pu(VI) and Pu(V) are reduced rapidly to Pu(IV) at pH 7. The half-life of the redox reactions Pu(VI)/(V) and Pu(V)/(IV) are in the range of minutes. The rates of both reduction reactions decrease with decreasing pH values. A portion of the Pu(IV) is not stable in the same groundwater and is reduced slowly to Pu(III) in the range of weeks. Ultrafiltration experiments show Pu to be totally bound to the humic substances in the groundwater. At Pu concentrations of 10-5to 10-4M, most of the Pu occurs as a Pu-colloid and/or Pu-colloid bound to humic substances (Pu-colloid-HS) in solution, which is indicated by EXAFS/XANES and XPS measurements.
Trivalent actinide coprecipitation with powellite (CaMoO4): Secondary solid solution formation during HLW borosilicate-glass dissolution
Authors: Bosbach Dirk , Rabung Thomas , Brandt Felix , Fanghänel Thomas
Published: December 2004

Powellite (CaMoO4) is one of the various crystalline secondary alteration phases which form during the corrosion of high level waste (HLW) glasses. Due to their structural variability, powellite can accommodate considerable chemical substitutions including trivalent actinides. Batch adsorption and coprecipitation experiments in mixed flow reactors have been used to study quantitatively the uptake of Cm(III) and Eu(III) (as a nonradioactive chemical homologue for trivalent actinides) from aqueous solution under repository relevant conditions. A metal ion concentration-independentKdof 1200 ml/g has been determined for adsorption above pH 4 up to 3 μmol/L Eu(III). The partition coefficient for coprecipitation varies between 10 and 800 depending on the precipitation rate. Time-resolved laser fluorescence spectroscopy has been used to study the aqueous complexation of Cm(III)/Eu(III) and MoO42-as well as their incorporation into the powellite crystal lattice during coprecipitation. A red shift of the Cm(III) fluorescence emission of the transition indicates the formation of aqueous CmMoO4+(598 nm) and Cm(MoO4)22-(601 nm) complexes. The incorporation of Cm(III) is indicated by a significant red shift. The corresponding lifetime of 165 μs indicates quench effects. A similar behaviour has been observed for Eu(III). The life time of the5D0-7F2transition is 350 μs for an incorporated Eu(III) species, suggesting also intrinsic quench effects, due to the local crystal field or impurities.
Contribution of minerals to the sorption of U(VI) on granite
Authors: Baik M. H. , Hyun S. P. , Cho W. J. , Hahn P. S.
Published: December 2004

Batch sorption experiments of U(VI) onto the surfaces of granite rock were carried out. The distribution of the sorbed U(VI) on crushed granite particles was investigatedviaa sequential chemical extraction method to quantify the amount of U(VI) sorbed on the mineral phases and by X-ray diffraction characterization of dried samples of the remaining minerals after each extraction step to determine the significant mineral phases that sorb U(VI). Chlorite among the constituent minerals, even though being present in a small amount, is assumed to contribute to the strong U(VI) sorption and most of the sorbed U(VI) was weakly bound to the granite surfaces. However, a discriminative amount of the sorbed U(VI) on granite particles was difficult to desorb, in particular, when sorption took place in the alkaline region. The distribution of the sorbed U(VI) both on the fresh intact surface and on the natural fracture surface was also investigated by a X-ray image mapping technique. The result shows that dominant minerals hosting the majority of the sorbed uranium are mica for the intact surface of granite and chlorite for the fracture surface of the granite.
Distribution and geochemical association of actinides in a contaminated soil as a function of grain size
Authors: Lee M. H. , Yoon Y. Y. , Clark Sue B. , Glover S. E.
Published: December 2004

The distribution of actinides in a contaminated soil as a function of grain size was investigated by determining 239,240Pu, 241Am, and 238U after size fractionation. The soil was contaminated as the result of a fire at a nuclear missile site in the US. In all cases, the activity of each isotope increased with decreasing particle size, although differences were observed for 238U. A simple spherical model was used to represent surface area as a function of grain size. Fitted values for the distributions of 239,240Pu and 241Am by this model correlated well with experimental values, suggesting that their association is a surface sorption phenomenon. Fitted values for 238U did not correlate with measured values, indicating that U association was not strictly a surface mechanism.

To further investigate the partitioning of these isotopes within each size fraction, sequential extractions were performed on the various size fractions. 239,240Pu, 241Am, and 238U are associated with primarily reducible, acid sulfide soluble, and refractory phases, with more total activity associated with the refractory phase for the smaller size fractions. Considering only the final refractory phase for each size fraction, the activity of 238U was greater than 239,240Pu and 241Am. In the context of the behavior of U as a function of grain size, this result suggests that a significant fraction of the U is primordial and incorporated into the refractory matrix, most likely the silicates and refractory clay minerals.
Luminescence properties of tetravalent uranium in aqueous solution
Authors: Kirishima Akira , Kimura Takaumi , Nagaishi Ryuji , Tochiyama Osamu
Published: December 2004

The luminescence spectra of U4+ in aqueous solutions were observed in the UV-VIS region at ambient and liquid nitrogen temperatures. The excitation spectrum indicates that the luminescence is arising from the deexcitation of a 5f electron at the 1
S
0 level and no other emissions of U4+ in aqueous solutions were detected for other f–f transitions. All the luminescence peaks were assigned to the transitions from 1
S
0 to lower 5f levels. To estimate the luminescence lifetime, luminescence decay curves were measured using time-resolved laser-induced fluorescence spectroscopy. At room temperature, the decay curve indicated that the lifetime was shorter than 20 ns. On the other hand, the frozen sample of U4+ in aqueous solution at liquid nitrogen temperature showed the same emission spectrum as at room temperature and its lifetime was 149 ns in H2O system and 198 ns in D2O system. The longer lifetime at liquid nitrogen temperature made it possible to measure the spectrum of U4+ at the concentration as low as 10-6 M. The difference in the anion species (ClO4
-, Cl-, SO4
2-) affected the structure of the emission spectrum to some extent.
Sorption behavior of europium(III) and curium(III) on the cell surfaces of microorganisms
Authors: Ozaki Takuo , Gillow J. B. , Kimura Takaumi , Ohnuki T. , Yoshida Zenko , Francis Arokiasamy J.
Published: December 2004

We investigated the association of europium(III) and curium(III) with the microorganismsChlorella vulgaris,Bacillus subtilis,Pseudomonas fluorescens,Halomonassp.,Halobacterium salinarum, andHalobacterium halobium. We determined the kinetics and distribution coefficients (Kd) for Eu(III) and Cm(III) sorption at pH 3-5 by batch experiments, and evaluated the number of water molecules in the inner-sphere (NH₂O) and the degree of strength of ligand field (RE/M) for Eu(III) by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Exudates fromC. vulgaris,Halomonassp., andH. halobiumhad an affinity for Eu(III) and Cm(III). The logKdof Eu(III) and Cm(III) showed that their sorption was not fully due to the exchange with three protons on the functional groups on cell surfaces. The halophilic microorganisms (Halomonassp.,Halobacterium salinarum,H. halobium) showed almost no pH dependence in logKd, indicating that an exchange with Na+on the functional groups was involved in their sorption. The Δ NH₂O(=9-NH₂O) for Eu(III) onC. vulgariswas 1-3, while that for the other microorganisms was over 3, demonstrating that the coordination of Eu(III) withC. vulgariswas predominantly an outer-spherical process. TheRE/Mfor Eu(III) on halophilic microorganisms was 2.5-5, while that for non-halophilic ones was 1-2.5. This finding suggests that the coordination environment of Eu(III) on the halophilic microorganisms is more complicated than that on the other three non-halophilic ones.
Results of the colloid and radionuclide retention experiment (CRR) at the Grimsel Test Site (GTS), Switzerland – impact of reaction kinetics and speciation on radionuclide migration
Authors: Geckeis Horst , Schäfer Thorsten , Hauser W. , Rabung Thomas , Missana T. , Degueldre C. , Möri A. , Eikenberg J. , Fierz Th. , Alexander W. R.
Published: December 2004

The influence of smectite colloids on the migration behaviour of U(VI), Th(IV), Pu(IV), Am(III), Np(V), Sr(II) and Cs(I) is investigated within the Colloid and Radionuclide Retardation experiment (CRR). Twoin situexperiments in a well-characterized granitic fracture zone are carried out in presence and absence of bentonite colloids. Radionuclide retardation observed in the field studies increases in the sequence Np(V)∼U(VI)<Sr(II)<Cs(I), where a small fraction of colloid borne breakthrough is only stated for Cs(I) in presence of bentonite colloids. Am(III) and Th/Pu(IV) mainly migrate as colloids without retardation in the presence and absence of smectitic colloids. The radionuclide migration behaviour is discussed on the basis of results obtained in laboratory batch sorption experiments and spectroscopic studies. Consistent with the field observation, laboratory derivedKdvalues increase in the order Np(V)∼U(VI)<Sr(II)<Cs(I). Significant kinetic hindrance for the sorption to fault gauge minerals is observed for Sr(II) and Cs(I), but notably for Am(III) and Pu(IV). The slow sorption reaction of tri- and tetravalent actinide ions is explained by their kinetically hindered dissociation from colloidal species. In order to explain the colloidal behaviour of tri- and tetravalent actinides even in absence of bentonite colloids, ultracentrifugation and spectroscopic experiments are performed. It is found that up to 60% of Pu(IV) and Am(III) species can be centrifuged off. Adding Cm(III) (5×10-8mol L-1) into both injection solutions instead of Am(III) allows for a spectroscopic study by using the time resolved laser fluorescence spectroscopy (TRLFS). Peak position and fluorescence lifetimes (λ=604 nm, τ=110-114 μs) together with the fact that Cm(III) can be widely separated by ultracentrifugation, suggest the existence of inner-sphere surface complexes on groundwater and bentonite colloids. CarbonK-edge XANES analysis of the bentonite colloids reveal the presence of natural organic constituents. They are mainly of aliphatic nature containing high fractions of carboxylate groups. A contribution of these organic species towards the bentonite colloid stability and sorption of actinides is assumed to be likely.
Comparison betweenin situand laboratory diffusion studies of HTO and halides in Opalinus Clay from the Mont Terri
Authors: Tevissen Etienne , Soler J. M. , Montarnal P. , Gautschi A. , Van Loon Luc R.
Published: December 2004

A long-term single-borehole diffusion experiment (DI) using tritiated water (HTO) and stable iodide (127I-) was carried out In the Opalinus Clay of the Mont Terri Underground Rock Laboratory (URL). Diffusion coefficientsDLand accessible porosity for HTO,36Cl-and125I-were also measured on centimetric Opalinus clay samples using the through diffusion technique. The evolution of tritium and iodide concentration in the injection system over time andin situprofiles were interpreted with a 3-D numerical simulation. A detailed analysis of the results pointed out the effect of a disturbed zone around the borehole with higher diffusion coefficients. The best estimate values for HTO and iodide in the undisturbed rock areDL= 5×10-11m2/s andDL= 1.5×10-11m2/s respectively. For the laboratory tests,DLvalues for HTO are in the range of 5×10-11m2/s to 8.5×10-11m2/s. For125I-and36Cl-the measured values areDL=νmber1.4×10-11andDL=1.6×10-11m2/s respectively.

All HTO results obtained with a through diffusion technique are within the same range as those obtained in thein situtests. TheDLvalues obtained in diffusion cells with125I-and36Cl-and the value drawn from the interpretation of stable127I-concentration profiles from thein situtests are very close. In fact, some significant uncertainties could be identified (i.e.a likely chemical retention of iodide on argillites, effect of the disturbed zone).
Simulating reactive transport in time dependent multiphase flow problems
Authors: Saaltink Maarten , Batlle Francisco , Ayora Carlos , Carrera Jesús
Published: December 2004

This paper discusses issues on time stepping and time weighing when simulating reactive transport in time dependent multiphase flow problems. It proposes to solve the flow and transport equation with different time increments. We analyze how the time varying flow properties should be evaluated in order to obtain correct solute mass balances. The proposed algorithm is illustrated by an example that models pyrite oxidation in an unsaturated soil. The example shows that flow and transport may require completely different time steps for numerical reasons and illustrates well the utility of using different time steps.
Chemical Potential of Charge Carriers in Solids
Authors: Maier Joachim
Published: December 2004

The contribution discusses the chemical potential of point defects (at or close to equilibrium) for a variety of cases: low and high concentration, electrons and ions, crystalline and amorphous materials, absence and presence of interactions, bulk and planar or curved interfaces, strained and unstrained situations, semi-infinite and finite boundary contributions.
Comparison of Dynamics of Ions in Ionically Conducting Materials and Dynamics of Glass-Forming Substances: Remarkable Similarities
Authors: Ngai K. L. , Habasaki J. , León C. , Rivera A.
Published: December 2004

We consider many of the fundamental dynamic properties of ionically conducting glasses, crystals and melts and show there are analogues in the dynamic properties of glass-forming substances. These similarities suggest the dynamics of these two classes of complex systems are governed by the same physics. We also show within each class, the evolution of dynamics from short time to long times are principally governed by the stretch exponent of the Kohlrasuch function, which determines either the primary relaxation of glass-formers or the conductivity relaxation of ionic conductors.
Chimpanzee Grooming as Social Custom
Authors: Zeller Anne
Published: December 2004

Chimpanzee Grooming as Social Custom. 2000. Nine minutes, color. documentary film by Linda Marchant. For more information, please contact Center for Media and Independent Learning, 2000 Center Street, Fourth Floor, Berkeley, CA 94704.
Personal Meaning, Self‐Representation, and Agency in Some Recent Works
Authors: Cravalho Mark A.
Published: December 2004

Inuit Morality Play: The Emotional Education of. Three‐Year‐Old. Jean L. Briggs. New Haven, CT: Yale University Press, 1998. 275 pp.

The Power of Feelings: Personal Meaning in Psychoanalysis, Gender, and Culture. Nancy J. Chodorow. New Haven, CT: Yale University Press, 1999. 320 pp.

Identity and Agency in Cultural Worlds. Dorothy Holland. William Lachicotte Jr. Debra Skinner. and Carol Cain. Cambridge, MA: Harvard University Press, 1998. 349 pp.
Men and Masculinities
Authors: Synnott Anthony
Published: December 2004

Masculinities: Football, Polo and the Tango in Argentina. Eduardo P. Archetti. New York: Berg, 1999. 212 pp.

Football Hooligans: Knowing the Score. Gary Armstrong. New York: Berg, 1998. 361 pp.

Manhood and Morality: Sex, Violence and Ritual in Gisu Society. Suzette Heald. New York: Routledge, 1999. 192 pp.

What It Means to Be. Man: Reflections on Puerto Rican Masculinity. Rafael L. Ramírez. translated by Rosa E. Casper. New Brunswick, NJ: Rutgers University Press, 1999 139 pp.
Archaeology and Language III: Artefacts, Languages and Texts
Authors: Dolukhanov Pavel
Published: December 2004

Archaeology and Language III: Artefacts, Languages and Texts. Roger Blench and Matthew Spriggs. eds. New York: Routledge, 1999.302 pp.
The Material Culture of Steamboat Passengers: Archaeological Evidence from the Missouri River
Authors: Kane Adam I.
Published: December 2004

The Material Culture of Steamboat Passengers: Archaeological Evidence from the Missouri River. Annalies Corbin. New York: Kluwer Academic/Plenum Publishers, 2000. 237 pp.
The Archaeology of Britain: An Introduction from the Upper Palaeolithic to the Industrial Revolution
Authors: Greis Gloria Polizzotti
Published: December 2004

The Archaeology of Britain: An Introduction from the Upper Palaeolithic to the Industrial Revolution. John Hunter and Ian B. M. Ralston. eds. New York: Routledge, 1999 328 pp.
Historical Linguistics: An Introduction
Authors: Thurgood Graham
Published: December 2004

Historical Linguistics: An Introduction. Lyle Campbell. Cambridge, MA: The MIT Press, 1999. 396 pp.
Lucy's Legacy: Sex and Intelligence in Human Evolution
Authors: Bartlett Thad Q.
Published: December 2004

Lucy's Legacy: Sex and Intelligence in Human Evolution. Alison Jolly. Cambridge, MA: Harvard University Press, 1999.518 pp.
The Anthropology of Food and Body: Gender, Meaning and Power
Authors: Avakian Arlene
Published: December 2004

The Anthropology of Food and Body: Gender, Meaning and Power. Carole M. Counihan. New York: Routledge, 1999.256 pp.
Life on the Outside: The Tamil Diaspora and Long‐Distance Nationalism
Authors: Burkhart Geoffrey
Published: December 2004

Life on the Outside: The Tamil Diaspora and Long‐Distance Nationalism. Øivind Fuglerud. Sterling, VA: Pluto Press, 1999.203 pp.
Siberian Survival: The Nenets and Their Story
Authors: Gray Patty A.
Published: December 2004

Siberian Survival: The Nenets and Their Story. Andrei V. Golovnev and Gail Osherenko. Ithaca: Cornell University Press, 1999. 176 pp.
States and Illegal Practices
Authors: Hunt Alan
Published: December 2004

States and Illegal Practices. Josiah McC. Heyman. ed. Berg: Oxford, 1999. 325 pp.
Folkbiology
Authors: Brown Cecil H.
Published: December 2004

Folkbiology. Douglas L. Medin and Scott Atran. eds. Cambridge, MA: MIT Press, 1999. 504 pp.
Death Squad: The Anthropology of State Terror
Authors: Bornstein Avram
Published: December 2004

Death Squad: The Anthropology of State Terror. Jeffrey A. Sluka. ed. Philadelphia: University of Pennsylvania Press, 2000. 260 pp.
African Roots of the Amistad Revolt
Authors: Adams Monni
Published: December 2004

Sierra Leone: The African Roots of the Amistad Revolt: Masks of the Sacred Bush. Peabody Museum of Natural History, Yale University, July 15, 2000– December 2000.
Beyond Picturing Culture: A Critique of a Critique
Authors: Guindi Fadwa El
Published: December 2004

Picturing Culture: Explorations of Film and Anthropology. Jay Ruby. Chicago: University of Chicago Press, 2000. 339 pp.
Metaphor and Material Culture
Authors: Pocius Gerald L.
Published: December 2004

Metaphor and Material Culture. Christopher Tilley. Maiden, MA: Blackwell, 1999.298 pp.
Patterns of Human Growth
Authors: Johnston Francis E.
Published: December 2004

Patterns of Human Growth. Barry Bogin. New York: Cambridge University Press, 1999.455 pp.
Racial Situations: Class Predicaments of Whiteness in Detroit
Authors: Kenny Lorraine D.
Published: December 2004

Racial Situations: Class Predicaments of Whiteness in Detroit. John Hartigan Jr. Princeton, NJ: Princeton University Press, 1999.354 pp.
What Causes Men's Violence against Women?
Authors: Yllo Kersti
Published: December 2004

What Causes Men's Violence against Women? Michéle Harway and James M. O'Neil. eds. Thousand Oaks, CA: Sage Publications, 1999. 296pp.
Iceman: Uncovering the Life and Times of a Prehistoric Man Found in an Alpine Glacier
Authors: Levy Janet E.
Published: December 2004

Iceman: Uncovering the Life and Times of. Prehistoric Man Found in an Alpine Glacier. Brenda Fowler. New York: Random House, 2000.296 pp.
Developing Conceptual Categories in Classroom Descriptive Research: Some Problems and Possibilities
Authors: SIPE LAWRENCE R.
Published: December 2004

This article reflects on a classroom study of children's literary responses to unpack the process of building conceptual categories in ethnographic research, thus challenging accounts that obscure the role of the researcher and present findings as fixed and infallible.
Cheats at Work: The Anthropology of Workplace Crime
Authors: Hochwald Eve
Published: December 2004

Gerald Mars 1982 Cheats at Work: The Anthropology of Workplace Crime Winchester: Nbss.: George Allen & Unwin. $6.95, Paperback
Farm Servants and Labour in Lowland Scotland, 1770‐1914
Authors: McCarthy John P.
Published: December 2004

T. M. Devine 1984 Farm Servants and Labour in Lowland Scotland, 1770‐1914, Edinburgh: John Donald Publishers.
Foundations of Social Theory
Authors: Gamst Frederick C.
Published: December 2004

James S. Coleman. 1990 Foundations of Social Theory Cambridge, MA: Harvard University Press, xviii. 993 pp.