bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photochemically Induced Exchange of Fluorine and β-Silyl Moieties in 2-Fluorophenyldisilanes
Authors: Kira Mitsuo , Tokura Satoshi 
Published: April 2006

Abstract
A novel type of photoisomerization of aryldisilanes, which involves 1,3-migration of a β-trimethylsilyl group from silicon to a fluorinated aromatic carbon accompanied by backward 1,3-migration of the fluorine to the α-silicon, was found during irradiation of 2,6-difluorophenyldisilanes.
A Novel High-Speed Pulsed Electric Dichroism Spectrophotometer with Multichannel Photodiode Detection System. Construction of Apparatus and Application to DNA-Dye Complex Solution
Authors: Yamaoka Kiwamu , Takata Noriyuki 
Published: April 2006

Abstract
The title apparatus with a 512 channel photo-detector was constructed for measuring electric linear dichroism (ELD) spectra of DNA-ethidium bromide in solutions. An ELD spectrum could be accumulated at a 280- or 140-nm interval under a single fast-orienting electric pulsed field.
Synthesis of Benzothiazolyl[2.2]metacyclophanes and Their Structural and Spectral Properties
Authors: Tsuge Akihiko , Ishii Tsutomu , Sawada Tsuyoshi , Mataka Shuntaro , Tashiro Masashi 
Published: April 2006

Abstract
Benzothiazolyl chromophore was introduced into the inner position of [2.2]metacyclophanes(= MCPs) which have various kinds of substituents at the outer position. Structural properties for such MCP derivatives were clarified by X-ray analysis. It was also found out that there exist specific relationships between the electronic nature of the outer substituent and λmax of the inner chromophore.
A New Triterpenoid Saponin (Chromosaponin I) with a Reducing Power
Authors: Tsujino Yoshio , Tsurumi Seiji , Osakai Toshiyuki , Saito Atsuyoshi 
Published: April 2006

Abstract
γ-Pyronyl-triterpenoid saponin (chromosaponin I; CSI) isolated from pea is strongly adsorbed at a glassy-carbon electrode, and gives an irreversible oxidation wave at 0.4 V vs. Ag/AgCl. The γ-pyronyl moiety is responsible for the electroactivity. CSI can reduce 1,4-benzoquinone, some of its derivatives and also cytochrome c. From comparison with other reductants, the formal redox potential of CSI was estimated to be 0.3–0.4 V vs. NHE (pH 7.0).
Oxidation of Long Alkyl-substituted Sexithiophene with FeCl3
Authors: Sato Masa-aki , Hiroi Masao 
Published: April 2006

Abstract
The visible-near IR and ESR spectral changes of long alkyl-substituted oligothiophene during the chemical oxidation indicated that the first oxidation yielded cation radicals (polarons) and the successive second oxidation did not dications (bipolarons) but trication radicals.
Novel Photo-Rearrangement of Oxime Methyl Ethers of 3-Acyl-1,2-dihydrocinnoline-N-phenyl-1,2-dicarboximides
Authors: Tanaka Satoko , Seguchi Kazuyoshi , Itoh Kuniaki , Sera Akira 
Published: April 2006

Abstract
Irradiation of conjugated imino ethers containing an adjacent 1,2-diazadicarboximide group in benzene afforded rearranged indole derivatives (3) and a novel dimer in good yields. The latter was formed by nucleophilic attack of 3 to a dipolar intermediate.
Synthesis of (1,5-Diazabicyclo[4.3.0]nonan-2-ylidene)pentacarbonylchromium and -tungsten Using Reaction of 2-Unsaturated Carbene Complexes with 6-Membered Hydrazine
Authors: Iyoda Masahiko , Zhao Li , Matsuyama Haruo 
Published: April 2006

Abstract
The reaction of styryl carbene complexes of chromium and tungsten with 6-membered hydrazine proceeded smoothly to give the bicyclic carbene complexes, together with dehydropiperidazine complexes.
Selective Formation of Acetal by Photooxidation of Ethanol over Silica-supported Niobium Oxide Catalysts
Authors: Tanaka Tsunehiro , Takenaka Sakae , Funabiki Takuzo , Yoshida Satohiro 
Published: April 2006

Abstract
UV-irradiation of silica-supported niobium oxide suspended in liquid ethanol under atmospheric oxygen led to the selective production of 1,1-diethoxyethane. The absence of oxygen or UV-irradiation with wavelengths of λ &gt; 320 nm remarkably suppressed the reaction. The activity normalized to the number of niobium ions suggests that the active site is highly dispersed niobate species. Ethanal is the primary product of the photooxidation and 1,1-diethoxyethane is formed by acid catalysis.
Tetraphenylstibonium Methoxide Promoting C-Alkylation of 2-Substituted Cyclic 1,3-Diketones
Authors: Fujiwara Masahiro , Hitomi Kazuhisa , Baba Akio , Matsuda Haruo 
Published: April 2006

Abstract
Selective C-alkylation of 2-methyl-1,3-cyclopentanedione and 2-methyl-1,3-cyclohexanedione was performed by using tetraphenylstibonium methoxide (Ph4SbOMe). The presence of a substituent at the 2-position was essential for C-alkylation.
Z-Selective Synthesis of Homoallylic Alcohols via 2-Alkenylation of Aldehydes by 1-(Tributylstannyl)-2-alkene
Authors: Miyake Hideyoshi , Yamamura Kimiaki 
Published: April 2006

Abstract
1-(Tributylstannyl)-2-alkene reacts with a solution of an aldehyde and BuSnCl3 to give (Z)-homoallylic alcohol. Z-Selective 2-methyl-2-butenylation can be accomplished by using (Z)-2-methyl-1-(tributylstannyl)-2-butene instead of 1-(tributylstannyl)-2-alkene. This reaction is useful as a new method to make (Z)-double bond. An application of the present method for a synthesis of pheromones is also described.
Polymerization of Pyrrole on a Roughened Gold Electrode Studied by Surface Enhanced Raman Scattering
Authors: Fujita Wataru , Ishioka Toshio , Teramae Norio , Haraguchi Hiroki 
Published: April 2006

Abstract
The polymerization of pyrrole adsorbed on a roughened gold electrode was studied by surface enhanced Raman scattering (SERS) spectroscopy. It was found that pyrrole was polymerized at −0.2 V vs. SCE and under open circuit. It is concluded that the polymerization of pyrrole occurs by the catalytic action of adatoms on a roughened gold electrode because pyrrole is adsorbed with the molecular ring parallel to the surface plane.
In-Situ Observation of Second Harmonic Lights from Amphiphilic Ruthenium(II) Tris(2,2′-bipyridine) Complex at Glass/Liquid Interface
Authors: Yamada Sunao , Yamada Yasuhiro , Nakano Takashi , Matsuo Taku 
Published: April 2006

Abstract
Interfacial second harmonic generation (SHG) from amphiphilic ruthenium(II) tris(2,2′-bipyridine) complex (RuC12B) was clearly observed with an alkaline-treated glass substrate in a RuC12B - ethylacetate solution, but not with an octadecylsilyl (ODS)-derivatized glass substrate. Interference fringe patterns due to SHG strongly indicate that RuC12B is adsorbed at the alkaline-treated glass surfaces, with its head group pointing toward the glass surfaces.
Three New Taxanes from the Roots of Taxus yunnanensis
Authors: Zhang Honjie , Takeda Yoshio , Minami Yoshinori , Yoshida Kenichiro , Matsumoto Takashi , Xiang Wei , Mu Oing , Sun Handong 
Published: April 2006

Abstract
Three new taxane type diterpenoids, taxuyunnanine B, C and D were isolated together with the known taxusin, 2α-deacetoxytaxinine J and taxinine J from the roots of Taxus yunnanensis and their structures were elucidated by spectroscopic means.
Deprotection of 1,3-Dithianes by 2,3-Dichloro-5,6-dicyano-p-benzoquinone (DDQ)
Authors: Tanemura Kiyoshi , Dohya Hiroshi , Imamura Masanori , Suzuki Tsuneo , Horaguchi Takaaki 
Published: April 2006

Abstract
A variety of 1,3-dithianes were converted to the corresponding carbonyl compounds in good yields by treatment with 1.5 equiv. of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in MeCN–H2O (9 : 1).
Advances in Horizontal Openhole Gravel Packing
Authors: Ali Syed , Grigsby Tommy , Vitthal Sanjay 
Published: April 2006

Summary
Technological advancement in horizontal drilling and openhole completing techniques for soft-rock formations finally has bridged the gap between the drilling and completion disciplines. The success achieved with openhole gravel packing has created a mainstay completion technique that has been used in deepwater developments in Brazil and West Africa to deliver reliable, high-rate well completions. The technology also has been an enabler for heavy-oil developments [American Petroleum Inst. (API) gravity &lt; 20°, y &gt; 0.934] in Brazil and the North Sea that otherwise would have been uneconomical.
This article discusses where the industry started, how technology has evolved, and the lessons learned that are being applied to increase the application envelope and reliability of this completion method. The review covers advances in openhole-drilling techniques that eliminate hole tortuosity, gravel-pack fluids that can reduce rig time and enhance well productivity, and improvements in downhole tools that have, or potentially will, reduce risk while reducing completion cycle time. This review also will briefly examine a possible replacement technology.
Reservoir Monitoring and Continuous Model Updating Using Ensemble Kalman Filter
Authors: Nævdal Geir , Johnsen Liv Merete , Aanonsen Sigurd Ivar , Vefring Erlend H. 
Published: April 2006

Summary
The use of ensemble Kalman filter techniques for continuous updating of a reservoir model is demonstrated. The ensemble Kalman filter technique is introduced, and thereafter applied to a simplified 2-D field model, which are generated by using a single horizontal layer from a North Sea field model. By as similating measured production data, the reservoir model is continuously updated. The updated models give improved forecasts and the forecasts improve as more data is included. Both dynamic variables, such as pressure and saturations, and static variables, such as the permeability, are updated in the reservoir model.
Reservoir-Simulation Study of Water-in-Oil Solubility Effect on Oil Recovery in the Steam-Injection Process
Authors: Luo Shanqiang , Barrufet Maria A. 
Published: April 2006

Summary
Water is usually considered insoluble in the oil phase; however, at the temperatures typically encountered in the steam-injection process, water may have higher than 40 mol% solubility in the oil phase. On a mass basis, experimental results from the literature indicate water solubility as high as 33%. We developed a practical and robust algorithm for a water/oil/gas three-phase flash calculation. The algorithm is based on the well-developed vapor/liquid two-phase flash-calculation algorithm and avoids trivial or false solutions commonly found in multiphase flash calculations. We also developed a fully compositional thermal reservoir simulator, considering water/oil mutual solubility, to study the effect of water-in-oil solubility on oil recovery in the steam-injection process. A simulation study shows that when water is soluble in the oil phase, it may increase oil recovery appreciably. We also found that the oil fluids should be characterized with at least three components for accurate compositional thermal reservoir-simulation study.
How Minimum Inhibitor Concentration (MIC) and Sub-MIC Concentrations Affect Bulk Precipitation and Surface Scaling Rates
Authors: Graham A. L. , Boak L. S. , Neville A. , Sorbie K. S. 
Published: April 2006

Summary
Conventional testing of scale inhibitors (SIs) usually focuses only on the inhibition of bulk depositional processes (e.g., in jar tests of inhibition efficiency). In previous work, we have extended the study of inhibition efficiency to examine both bulk and surface depositional processes and their inhibition using SIs. Where the minimum inhibitor concentration (MIC) is well exceeded, both bulk and surface scaling are prevented. However, we have demonstrated that the presence of an inhibitor, at levels marginally below the MIC, actually enhances surface scale growth over a range of temperatures typically encountered in the production system. Where this precise concentration lies with respect to the MIC is not generally known for scaling systems, and it is therefore difficult to predict where potential problems with sub-MIC SI levels would occur.
An experimental program has been conducted to assess the efficiency of PPCA (a polyphosphinocarboxylic acid inhibitor species) in inhibiting barium sulfate scale formation in the bulk solution and on a metal surface over a range of concentrations and test temperatures. The concentration range tested was chosen (a) to allow identification of the MIC at which both surface and bulk scale formation is controlled and (b) to establish where potential problems with enhanced surface scaling arise at sub-MIC levels. The results obtained from this study have allowed trends in surface and bulk inhibition to be established and allowed the region of sub-MIC concentrations where surface scaling is enhanced to be identified for three temperatures. We summarize our results using some simple schematic models of the bulk and surface scaling regimes and the corresponding inhibition process.
Sisters, wives, wards and daughters: a transformational analysis of the political organization of the Tiv and their neighbours. Part II: The transformations
Authors: Fardon Richard 
Published: April 2006

Opening ParagraphIn the first part of this article I set myself two objectives, each of which took its cue from a generalization made about the political and social organization of the Tiv by their principal ethnographers, Laura and Paul Bohannan. I proposed to challenge the related views (1) that the political organization of the Tiv could adequately be described as a segmentary lineage organization and (2) that their organization was atypical of the area of middle-belt West Africa in which the Tiv live. Confining my attention to Tiv ethnogaphy, I argued in Part I that a persuasive case could be made for a more complex account of Tiv political processes which recognized the salience not only of descent but also of marriage, kinship and local competition for the achievement of personal prestige through manipulation of marriage strategies, mastery of the major akombo or cults and claims to the possession of legitimate tsav or supernatural power. Tiv society still retains remarkable features on this view of its political processes, but they are not those of complete atypicality. Instead, it becomes apparent that, while sharing many of its core institutions with neighbouring societies, Tiv culture combines them in a unique manner. The uniqueness of the combination becomes visible through the effects of Tiv social organization, the more important of which I would itemise as:1. The persistence of Tiv culture and identity in a region of generally fragmented populations.2. The capacity for expansion of Tiv society.3. The capacity of Tiv society to absorb so many circumstances conducive to the development of hierarchy yet to remain, by and large, acephelous.
Trade, accumulation and the state in Asante in the nineteenth century
Authors: Arhin Kwame 
Published: April 2006

Opening ParagraphThis article examines well-known facts about Asante trade in the nineteenth century with a view to defining the contribution of trade to accumulation. The question of accumulation becomes significant when considered in relation to recent directions in Asante economic, social and political history. These have featured the role of the precolonial Asante state in the development of its economy (Wilks, 1967; 1975; McCaskie, 1980), stratification (Wilks, 1975; McCaskie, 1980; 1983; 1986; Arhin, 1983a; 1983b; 1986a), and what may be called the paradox of colonial rule, that it liberalised accumulative forces in order to enhance its exploitative opportunities (Arhin, 1974; 1975).
Social stratification on the Swahili coast: from race to class?
Authors: Constantin François 
Published: April 2006

Opening ParagraphThe analysis of ‘social stratification’ (a polite way of speaking of inequality) is crucial to that of political power, though not easy, regardless of the social group investigated. At the cost of oversimplification, die-hard theoreticians minimise the problem by using ready-made typologies and causal links purporting to explain all living social structures.
Tukulor weavers and the organisation of their craft in village and town
Authors: Dilley Roy 
Published: April 2006

Opening ParagraphThe subject of weavers has until recently received surprisingly little detailed attention from writers on Africa, given the importance of cloth in local and regional trade, particularly in West Africa. Yet, even here, cloth trading has received scholarly attention in the works of Hodder (1967, 1980) and of Johnson (1973, 1976, 1977, 1978, 1980). In addition crafts and craftsmen have been the subject matter of occasional papers and collected works (for example, d'Azevedo, 1973; Hallpike, 1968; Llovd, 1953; Murray, 1943), but few authors have concentrated on weavers alone. More specifically African cloth and textiles have received greater coverage in the works of Picton and Mack (1979) and of the Lambs (1975, 1980, 1981, 1984), though the actual organisation of production has by and large been overlooked. Before the publication of Esther Goody's collection From Craft to Industry in 1982, which has provided us with two examples of the development of cloth production for market in Nigeria and Ghana, possibly the only article to deal with the organisation of traditional weaving is Bray's (1968) contribution on weaving in Iseyin, Nigeria.
Spirit media: the electronic media and Islam among the Dyula of northern Côte d'Ivoire
Authors: Launay Robert 
Published: April 2006

AbstractIn 1973 the Muslim Dyula of northern Côte d'Ivoire, in their quarter of Korhogo town or in the villages, listened to the radio and might occasionally see an Italian ‘western’ at the cinema. Television was an exotic rarity; cassettes were a novelty. By 1984 television was ubiquitous; households that had not been interested in radio were now enthusiastic about watching television in the evening. Cassettes had become even more common than radios, and tapes were pirated and copied. The shift from radio and film to television and cassettes brought religion more fully into the forefront of the electronic media. For Muslims, religious cassettes consisted of sermons or ‘recitations’ in Dyula. Sermons, given in the open air and accompanied by refreshments, are festive occasions, a spectacle where the audience expects to be entertained. The form of the sermon bears a striking resemblance to Mande epic recitation, and are readily taped by individuals in the audience, to be listened to as entertainment; they are not a commercial commodity. Sermons on television, however, have very different requirements: the Thursday evening Muslim ‘show’ has younger, Saudi-oriented clerics who are not allowed to ramble; the ‘show’ is tightly scripted, with precise times allotted; clerics read from a text rather than quote from memory,extempore. Despite the generational divide in tastes and styles, the two genres still coexist side by side—though for how long?
Transition from Preclassic to Classic at Teotihuacán
Authors: West Michael 
Published: April 2006

AbstractFour years of intensive archaeological survey, supplemented by excavations in the Teotihuacán Valley, Mexico, have greatly clarified our picture of the transition from Preclassic to Classic. The definition of two new phases of culture history, Tezoyuca and Patlachique, that belong to the Terminal Preclassic (post Late Ticoman) strongly suggests a local development of the great Classic city of Teotihuacán. This runs counter to the hypothesis that a great migration, possibly from the Gulf Coast region, was responsible for the fully developed Classic Teotihuacán culture. Present evidence indicates that the Patlachique phase is intrusive and appears in the Teotihuacán Valley possibly as the result of migrations from the southern Valley of Mexico, perhaps precipitated by the eruption of the volcano Xitli. When peoples carrying this culture entered the Teotihuacán Valley, they encountered the Tezoyuca culture and gradually absorbed it. The fusion of these two groups eventually produced Tzacualli, which is the first recognizable phase of the Teotihuacán culture.
On Puerto Rican Archaeology
Authors: Alegría Ricardo E. 
Published: April 2006

AbstractHistorical sources corroborated by archaeological research demonstrate that the Antillean area was inhabited by people of three cultural traditions. Puerto Rico, because of its intermediate position between the Greater and Lesser Antilles, is of great importance in determining the chronology and the distribution of West Indian aboriginal cultures. Recent radiocarbon dates demonstrate that Puerto Rico was first populated by a preceramic people who arrived before the Christian era. A relationship between these Indians and certain preceramic groups of Venezuela has been postulated, although neither the chronology of the sites nor their distribution correspond. Other radiocarbon dates from Puerto Rico establish a clear relationship between the different pottery styles of the island and those of the Lesser Antilles and Venezuela.
New Perspectives on Jamaican Archaeology
Authors: Howard Robert R. 
Published: April 2006

AbstractRecent investigations still yield no sign of preceramic or of Arawak occupation of Jamaica before early Period III in the Rouse chronology. Jamaican sites indicate a characteristically Arawakan culture, but they lack the ceremonial elaboration developed in Haiti. Jamaican pottery shows relatively little change through time and only minor local variation. Four distinct styles are present: (1) Little River from early Period III; (2) White Marl, the dominant style of the island; (3) Montego Bay, probably the latest in time; and (4) a little-known Red Ware whose chronological position is not clear. The closest stylistic affiliations are with Bani of Cuba and Meillac of Haiti. The late Carrier style of Haiti did not diffuse to Jamaica. Certain distinctive burial practices and features of village construction have been revealed by recent excavations at White Marl and other southern coast sites.
Gordon Creek Woman Meets Kennewick Man: New Interpretations and Protocols Regarding the Peopling of the Americas
Authors: Swedlund Alan , Anderson Duane 
Published: April 2006

AbstractRecent discoveries—particularly those of Kennewick Man—have renewed debates on the peopling of the Americas. Our vantage point comes from research on the Gordon Creek Burial which commenced some 30 years ago. We suggest that a contrast between the conditions under which Gordon Creek and Kennewick were recovered and analyzed provides insights into current interpretations and controversies. Specifically, we argue that bioarchaeologists cannot, and therefore should not, separate the sociopolítical issues from the scientific, that biological assignments of affiliation are extremely problematic in such cases, and that prior assumptions figure strongly in the interpretations presented. If more detailed understanding of the peopling of the Americas is a common goal, then we as bioarchaeologists must be prepared to reexamine our practices and learn from our mistakes.