bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ice Processes Affect Habitat Use and Movements of Adult Cutthroat Trout and Brook Trout in a Wyoming Foothills Stream
Authors: Lindstrom Jason W. , Hubert Wayne A. 
Published: December 2004

Abstract
Habitat use and movements of 25 adult cutthroat trout Oncorhynchus clarkii and 25 adult brook trout Salvelinus fontinalis from fall through winter 2002–2003 were assessed by means of radiotelemetry in a 7-km reach of a Rocky Mountains foothills stream. Temporal dynamics of winter habitat conditions were evaluated by regularly measuring the features of 30 pools and 5 beaver Castor canadensis ponds in the study reach. Groundwater inputs at three locations raised mean daily water temperatures in the stream channel during winter to 0.2–0.6°C and kept at least 250 m of the downstream channel free of ice, but the lack of surface ice further downstream led to the occurrence of frazil ice and anchor ice in pools and unstable habitat conditions for trout. Pools in segments that were not affected by groundwater inputs and beaver ponds tended to be stable and snow accumulated on the surface ice. Pools throughout the study reach tended to become more stable as snow accumulated. Both cutthroat trout and brook trout selected beaver ponds as winter progressed but tended to use lateral scour pools in proportion to their availability. Tagged fish not in beaver ponds selected lateral scour pools that were deeper than average and stable during winter. Movement frequencies by tagged fish decreased from fall through winter, but some individuals of both species moved during winter. Ice processes affected both the habitat use and movement patterns of cutthroat trout and brook trout in this foothills stream.
Generation of complex Metal Oxides by Aerosol Processes: Superconducting ceramic particles and films
Authors: Kodas Toivo T. 
Published: December 2004

AbstractComplex metal oxides, including ferroelectric, ferrimagnetic and superconducting ceramics, have a variety of technologically useful properties that can be exploited for a number of applications. Fabrication of complex metal oxide ceramics with specific properties requires high‐purity powders with controlled chemical compositions, size distributions, and morphologies. Powders with these characteristics can be produced by aerosol processes in which fine particles are generated in gaseous flow systems. The particles can also be deposited from the gas phase onto surfaces to form films. This paper will discuss the use of aerosol processes for the generation of complex metal oxide powders. A review of aerosol processes will be presented first, followed by a discussion of the methods used for the generation of superconducting ceramic powders. Examples include the production of YBa2Cu3O7, La1.85Sr0.15CuO4, and Tl‐Ca‐Ba‐Cu‐O powders and films. Emphasis will be placed on defining the conditions required for the generation of chemically homogeneous particles with controlled morphologies.
Advanced Catalysts: Interfaces in the physical and biological sciences
Authors: Thomas John M. 
Published: December 2004

The presidential addressto the chemistry section of the British Association for the Advancement of Science (BAAS) to be given in Sheffield in September by John Thomas (see picture) concentrates on the roles that catalysts play in chemical synthesis both in industry and in a biological environment. The future of catalysts rests in the hands of interdisciplinary scientists and engineers who, when faced with the problem of developing a new catalytic system, can call upon experience from such diverse fields as solid state physics and biology.magnified image
Polymers with a high refractive index and low optical dispersion
Authors: Simmrock Hans‐U. , Mathy Alfred , Dominguez Ligia , Meyer Wolfgang H. , Wegner Gerhard 
Published: December 2004

Organic Polyelectrolytes (I‐VII) known as Ionenes, with unique combinations of high refractive index (ND) and high Abbe number (VD, see figure) now compete with inorganic glasses for application in optics. Variation of the counterions allows the tuning of their chemical and optical properties. magnified image
Designing Luminescent Materials
Authors: Bredol Michael , Kynast Ulrich , Ronda Cornelis 
Published: December 2004

Review: Non‐conventional phosphor host materials such as cryptands (see Figure) or zeolites now offer potential alternatives to the traditional inorganic solid‐state materials which find applications in e.g. fluorescent lamps, T.V. sets, or X‐ray detectors. Recent efforts to further optimize conventional materials are reviewed and a forward look is taken at the new‐generation materials which could further extend the physical limits of luminescence.magnified image
The discovery of hidden arsenic species in coastal waters
Authors: Howard A G , Comber S D W 
Published: December 2004

AbstractThe analysis of ultraviolet (UV)‐irradiated and untreated seawater samples has shown that the dissolved arsenic content of marine waters cannot be completely determined by hydride generation–atomic absorption spectrophotometry without sample pretreatment. Irradiation of water samples obtained during a survey of arsenic species in coastal waters during the summer of 1988 gave large increases in the measured speciation. Average increases in the measured speciation. Average increases in total arsenic, monomethylarsenic and dimethylarsenic were 0.29 μg As dm−3 (25%), 0.03 μg As dm−3 (47%) and 0.12 μg As dm−3 (79%), respectively. Overall, an average 25% increase in the concentration of dissolved arsenic was observed following irradiation.This additional arsenic may be derived from compounds related to algal arsenosugars or to their breakdown products. These do not readily yield volatile hydrides when treated with borohydride and are not therefore detected by the normal hydride generation technique. This has important repercussions as for many years this procedure, and other analytical procedures which are equally unlikely to respond to such compounds, have been accepted as giving a true representation of the dissolved arsenic speciation in estuarine and coastal waters. A gross underestimate may therefore have been made of biological involvement in arsenic cycling in the aquatic environment.
Encapsulation of organotin compounds in metal acetate glasses
Authors: Duffy John A , Harston Paul , Wardell James L , Smith Peter J 
Published: December 2004

AbstractTriorganotin halides, oxides and sulphides can be dissolved in molten, mixed‐metal acetates at ca 140–160°C without decomposition; quenching provides glasses into which are encapsulated the organotin species. Halide/acetate and oxide/acetate, but not sulphide/acetate, exchanges occur in the melt. Only partial exchange was found for hindered trineophyl tin chloride [(PhCMe2CH2)3SnCl], in contrast to the complete exchanges observed for the butyl (Bu), phenyl (Ph) and cyclohexyl (Cy) analogues. Complete oxide/acetate exchange was found for (Bu3Sn)2O, partial exchange occurred for (Cy3Sn)2O, whilst no exchange resulted with bis(trineophyltin) oxide or (Ph3Sn)2O. Tin–tin bonds (e.g. as in Ph3SnSnPh3) and carbon–tin bonds (even the allyl–Sn bond in Bu3SnCH2CHCH2) are not affected. The acetate glasses dissolve in aqueous media with release of the organotin species and they have potential as slow‐release systems which is currently being investigated.
Iron‐containing organometallic compounds as flame‐retarding/smoke‐suppressing additives for semi‐rigid poly(vinyl chloride)
Authors: Carty P , Adger B M 
Published: December 2004

AbstractThe incorporation of a range of iron‐containing organometallic compounds into a cable and wire poly(vinyl chloride) (PVC) formulation has been investigated. Limiting Oxygen Index and smoke density data were obtained across a range of formulations and the effects of the compounds on flammability and smoke generation are discussed. All the organoiron compounds markedly reduce smoke formation and some of them synergistically reduce the flammability of the polymer.
Iridium carbonyl clusters with pyridylphosphines: [Ir4(CO)9(PPhxpyl3−x)3]
Authors: Wajda‐Hermanowicz K , Koralewicz M , Pruchnik F P 
Published: December 2004

Abstract[Ir4(CO)9(PR3)3] type complexes were obtained in the reaction between Ir4(CO)12 and the 2‐pyridylphosphines: diphenyl(2‐pyridyl)phosphine (PPh2pyl), phenylbis(2‐pyridyl)phosphine (PPhpyl2), tris‐(2‐pyridyl)phosphine (Ppyl3) (pyl = 2‐pyridyl) in methanol in basic medium, in the presence of carbon monoxide. The reaction conditions were determined and the products were spectroscopically characterized.
Chemical form of arsenic in marine macroalgae
Authors: Morita Masatoshi , Shibata Yasuyuki 
Published: December 2004

AbstractChemical forms of water‐soluble and lipid soluble arsenic compounds in marine macroalgae, including edible algae, are reviewed. Major watersoluble arsenic compounds inalgae are arseniccontaining ribofuranosides (ACRs). Red and green algae contain mainly a glycerophospho derivative at the glycerol terminal while brown algae contain a sulfate or sulfonate derivatives at the glycerol terminal together with a glycerophospho derivative. Brown algae which belong to the Sargasso species contain significant amounts of inorganic arsenic in the form of arsenate. Lipid‐soluble arsenic identified in a brown algae (Undaria pinnatifida) was an acylated derivative of an ACR. Thirty‐eight marine algae were analyzed by HPLC/ICP/MS and their arsenic compounds are characterized. The characterization of arsenic compounds may show their role in the chemical taxonomy of algae species in addition to giving an understanding of the toxicological and geochemical implication of the element.
Chemical form of arsenic compounds and distribution of their concentrations in the atmosphere
Authors: Nakamura Masaru , Matsuzono Yoshiaki , Tanaka Shigeru , Hashimoto Yoshikazu 
Published: December 2004

AbstractIn order to understand the chemical form of arsenic compounds and their distribution in unpoluted areas, concentrations of arsenic compounds in the marine atmosphere were measured in several islands in several oceans. Furthermore, concentration of arsenic compounds were also measured between Tokyo and the Syowa station during a cruise by the Antarctic observation boat Shirase. Aerosols in the marine atmosphere were collected by a high‐volume air sampler with a quartz fiber filter. After extracting a sample, an analysis of arsenic compounds in the sample solution was carried out by hydride generation atomic absorption spectrophotometry combined with a cold trap of liquid nitrogen. This technique has a high analytical sensivity, so that it is suitable to determine arsenic compounds at trace level.The atmospheric concentrations of arsenic compounds were at the same level over the Pacific Ocean and the Atlantic Ocean. The concentration range of arsenic compounds over these oceans was 100–200 pg m−3 for inorganic arsenic, 10–20 pg m−3 for inorganic arsenic. It is considered that these values are the background concentrations in the northern hemisphere. On the other hand, over he Antarctic Ocean in the southern hemisphere, the atmospheric concentrations of inorganic arsenic were very low, and organic arsenics were little found. This fact indicates that arsenic in the atmosphere is strongly influenced by anthropogenic sources.
Comparative study on the tumorigenicity in mice of gallium arsenide, gallium phosphide and gallium oxide following subcutaneous and intraperitoneal injections
Authors: Tanaka Akiyo , Hisanaga Akira , Hirata Miyuki , Ishinishi Noburu 
Published: December 2004

AbstractChronic toxicity, including tumorigenicity, of gallium arsenide (GaAs), gallium phosphide (GaP) and gallium oxide (Ga2O3) was studied in male ICR mice which received either a subcutaneous or an intraperitoneal injection of each material once only. The doses received either subcutaneously or intraperitoneally were 48 mg Kg−1 as Ga or 480 mg Kg−1 as Ga of each material suspended in 0.2 cm3 of olive oil. The control groups received the vehicle only, either subcutaneously or intraperitoneally.In the study using subcutaneous injections, no tumors were observed in the subcutis at the site of injection, and there was no significant difference concerning the survival periods of each group compared with the control group at the termination of the observation period.In the study using intraperitoneal injections, the total tumor incidence in all the experimental groups, except for the GaAs (480 mg Ga Kg−1) groups, was significantly different compared with the control group. However, all these tumors appeared to be spontaneous, rather than induced by the materials themselves. Moreover, in the GaAs (480 mg Ga Kg−1) and Ga2O3 (48 mg Ga Kg−1) groups, the number of survival days was significantly lower compared with the control group.From this study, it seems that neither GaAs, GaP nor Ga2O3 were tumorigenic to mice when injected subcutaneously. Although it remains unclear whether the increased production of total tumors in each group following intraperitoneal injections was directly due to the tumorigenic action of GaAs, GaP or Ga2O3 or not, it appears that these substances produce a potential systemic toxicity in mice following intraperitoneal injections.
Metabolism in mice of arsenic compounds contained in the red alga Porphyra yezoensis
Authors: Shiomi Kazuo , Chino Makoto , Kikuchi Takeaki 
Published: December 2004

AbstractArsenic compounds in the red alga Porphyra yezoensis were purified by gel filtration on Bio‐Gel P‐2; chromatographic behavior suggested that they were arsenic‐containing ribofuranosides (arsenosugars). When partially purified arsenosugars were orally administered to mice, 86% and 13% of the arsenic administered were excreted in feces and urine, respectively, within 48 h. Arsenic compounds excreted in feces were identified as arsenosugars by gel filtration and highperformance liquid chromatography, while those excreted in urine were identified as methylarsonic acid, dimethylarsinic acid and arsenobetaine. On the other hand, upon intravenous administration of arsenosugars, a large part of the arsenic administered was excreted rapidly in urine; after 72 h, 92% of the arsenic administered was recovered in urine and 6% in feces. Similarly to the case of oral administration, methylarsonic acid, dimethylarsinic acid and arsenobetaine were detected in urine.
Reactivity of isopropenylacetylene, HCCC(CH3)CH2, in the presence of the complex [Ni(NCS) {CCC(CH3)CH2}(PPh3)2]
Authors: Furlani A. , Russo M. V. 
Published: December 2004

AbstractThe reactivity of isopropenylacetylene (IP) in the presence of [Ni(NCS){CCC(CH3)CH2}(PPh3)2] has been examined. 1,2,4‐Tris(isopropenyl)benezene (1,2,4‐TIB), two isomeric tetramers formed by reaction of 1,2,4‐TIB with IP, and polymeric fractions have been separated and characterized by IR, NMR and mass spectra. Stability of reaction products towards oxygen and humidity has also been investigated.
Variability of butyltin determination in water and sediment samples from european coastal environments
Authors: Quevauviller Ph. , Donard O F X 
Published: December 2004

AbstractA large amount of data has appeared in the literature within the last few years dealing with the monitoring of butyltin compounds in coastal environments. However, the strategies used strongly differed from one author to another, which led to difficulties in the comparison of contamination levels and the evaluation of long‐term trends. In this paper, different causes of pitfalls due to uncontrolled sources of variability are addressed; they involve precautions to be undertaken for the monitoring of butylins in water and sediment, particularly: sample collection; sample pretreatment (filtration/centrifugation, acidification, sieving); sample storage (different methods for storage and drying procedures); variability over the same site; variations over a tidal cycle; and variability due to diffusion (e.g. due to flushing).
Ionic alkyl‐lead, tetra‐alkyl‐lead and total lead in fish from the Great Lakes
Authors: Forsyth D S , Dabeka R W , Cleroux C 
Published: December 2004

AbstractFillets from a variety of fish species collected from Lakes Ontario, Superior and Erie, Canada, were examined for ionic alkyl‐lead, tetra‐alkyl‐lead and total lead compounds. Diphenylthiocarbazone (dithizone)‐derivatized extracts were collected at pH 8 and 9 for ionic alkyl‐leads from enzymatically hydrolyzed samples. Butylated derivatives were formed prior to analysis by gas chromatography‐atomic absorption spectrometry (GC AA). Tetra‐alkyl‐lead was extracted from the hydrolyzates with hexane.Most of the fillets contained low (<0.08–2 ng g−1) levels of trimethyl‐lead. Several samples contained triethyl‐lead or tetraethyl‐lead. Dimethyl‐lead, diethyl‐lead and tetramethyl‐lead were detected by GC MS but were below the GC AA method detection limit of 0.06 ng g−1, 0.09 ng g−1 and 0.2 ng g−1 respectively. Total lead levels were between <1.8 and 96.7 ng g−1.
Pyrolysis of metallocene complexes (ηC5H4R)2MR: An organometallic route to metal carbide (MC) materials (M = Ti, Zr, Hf)
Authors: Lang Heinrich , Seyferth Dietmar 
Published: December 2004

AbstractThe following compounds were prepared and their pyrolysis in a stream of argon was studied: (η5‐C5H5)2Ti(CCC6H5)2, (η5‐C5H4SiMe3)2‐Ti(SH)2, [(η5‐C5H5)Ti(μ‐CH2)]2, (η5‐C5H5)2ZrR2‐(RCH2, CH2C6H5, N(CH3)2), (η5‐C5H4CH3)2‐Zr(CCC6H5)2, [(η5‐C5H4SiMe3)2Zr(μ‐S)]2, [(η5‐C5H4SiMe3)2Hf(μ‐S)]2 and (η5‐C5H4SiMe3)2Hf‐(CCC6H5)2. The products of bulk pyrolysis of these materials were formed in 20–40% yield, based on the charged sample weight, and consisted mainly of titanium carbide together with small amounts of amorphous carbon.
Laser evaporation of some solid organosilicon polymers
Authors: Pola J , Vitek J , Polyakov Yu P , Guselnikov L E , Matveychev P M , Bashkirova S A , Tläskal J , Mayer R 
Published: December 2004

AbstractContinuous wave (cw) CO2 laser irradiation of some organosilicon polymers composed of ‐Me2Si‐, ‐Me2SiMe2SiCH2‐, RMeSi‐ and RMeSiMe2SiCH2CH2‐ units (where R = methyl, adamantyl, phenyl and hydrogen) leads to the evaporation of the polymer and is dominated by the formation of a solid deposit that has a continuous structure. It is assumed that chemical changes occur prior to the transfer of ejected material to the gas phase and that these consist mainly of the formation of high molecular biradicals or 1,2‐disilacyclobutane monomer that both re‐polymerize spontaneously upon their deposition onto a nearby cold surface. The mechanism of these specific decompositions of the polymers is assessed on the basis of the IR spectra of the deposits and, for the minor gaseous products, identification by GC MS techniques.
Analytical methods for airborne arsine, silane and dichlorosilane by adsorption sampling and AA spectrophotometry
Authors: Matsumura Yoshimi , Ono‐Ogasawara Mariko , Furuse Mitsuya 
Published: December 2004

AbstractAnalytical methods for arsine, silane and dichlorosilane by adsorption sampling and elemental analysis with graphite furnace AA were studied to establish convenient methods for atmospheric contamination surveys. This study included the following five items: (1) primary selection of adsorbents applicable to adsorption sampling; (2) examination of the adsorption capacities of the adsorbents for the gases; (3) improvement of the adsorbents by chemical modification; (4) desorption of the gases adsorbed on the adsorbents with solvents; and (5) quantitative analysis of arsenic and silicon in the solutions.Experimental results showed that active carbon made from synthetic thermosetting resin beads contained no aresenic and little silicon as impurities. This active carbon by itself was proved to adsorb arsine and dichlorosilane, but not silane. Impregnation with sodium hydroxide of the active carbon improved the adsorption capacity for all three gases. Refined silica gel, free from arsenic contamination, did not adsorb arsine by itself but potassium permanganate impregnation produced an adsorption capacity for arsine.The adsorbed arsine on the active carbon was desorbed into a hot dilute nitric acid solution with high efficiency (over 90%), but arsine adsorbed on sodium hydroxide impregnated active carbon or on potassium permanganate impregnated silica gel was dissolved into various solutions only at lower efficiencies. Silane adsorbed on sodium hydroxide‐impregnated active carbon was desorbed with hot water with an efficiency higher than 90%. Dichlorosilane adsorbed on the active carbon with or without sodium hydroxide impregnation was desorbed with a nitric acid solution with efficiency of 85%. The lower determination limit for arsine able to discriminate from background interference of arsenie was 0.005 ppm, and those for silane and dichlorosilane were each 0.05 ppm for 3‐dm3 air samples.
Silicone curing and polyurethane preparation promoted by latent organotin catalysts
Authors: Jousseaume B , Gouron V , Pereyre M , Francès J‐M 
Published: December 2004

AbstractThe use of new latent organotin cataylsts has been investigated for silicone curing and polyurethane preparation. These functional tetraorganotins are inactive at room temperature and liberate in situ the active species, diorganotin dicarboxylates, when heated. They confer long pot‐lives to the mixtures in which they are incorporated. Upon heating, these mixtures are rapidly cured or polymerized after a short activation period.
Photochemistry of iron pentacarbonyl adsorbed on titanium dioxide
Authors: Ukisu Yuji , Sato Shinri , Ohmori Tadayoshi 
Published: December 2004

AbstractThe photolysis of iron carbonyl (Fe(CO)5) adsorbed on titanium dioxide (TiO2, anatase) was studied by FT‐IR spectroscopy. When adsorbed Fe(CO)5 is illuminated by visible and near‐UV light, the IR spectrum of its photolysis products is hardly observed, indicating that most of the Fe(CO)5 is photodecomposed to iron(0) or iron oxides on TiO2. The carbon monoxide (CO) evolution rate upon illumination depends on the wavelength of light; 433 nm light is more effective for CO evolution than 366 nm light. This result implies that the band‐gap excitation of TiO2 has little effect on the photolysis of adsorbed Fe(CO)5, since the absorption edge of TiO2 (anatase) lies at around 400 nm. The effects of substrates on the photolysis of adsorbed Fe(CO)5 are discussed with reference to previous results obtained for aluminium oxide (Al2O3) and silicon dioxide (SiO2), on which the photolysis leads to the formation of Fe2(CO)9 or Fe3(CO)12.
Synthesis and spectroscopic characterization of organotin derivatives of N‐benzoylglycylglycine
Authors: Ruisi Giuseppe , Giudice Maria Teresa Lo 
Published: December 2004

AbstractDi‐ and tri‐organotin derivatives of N‐benzoylglycylglycine (HBzGlyGly) were synthesized and characterized by infrared, 1H, 13C NMR and 119Sn Mössbauer spectroscopy. Diorganotin derivatives appear to be dimer distannoxanes ([R2SnBzGlyGly]2O)2 (R = CH3, n‐C4H9, n‐C8H17) with a ladder‐type structure where tin atoms are five‐coordinated and N‐benzoylglycylglycine alternatively acts as a unidentate or bridging bidentate ligand through the carboxylate group. For triorganotin derivatives R3SnBzGlyGly (R= CH3, n‐C4Hg) we propose a polymeric structure where N‐benzoylglycylglycine bridges planar SnC3 units through the carboxylate group.