Soft chemical synthesis of new layered and three-dimensional oxide hydrates, hxVxW1-xO3×yH2O, related to WO3×2 H2O and WO3. times.1/3 H2O

Two new vanadium-tungsten oxide hydrates of the formulas, H0.125V0.125W0.875O3.1.5H2O (I) and Ho.33V0.33W0.67O3.1/3H2O (II), have been synthesized by acid-leaching of LiVWO6 with aqueous HNO3/HCl. While phase I obtained by treatment of LiVWO6 with dilute HNO3/HCl possesses an orthorhombic structure (a = 7.77(3), b = 13.87(6), c = 7.44(3) angstrom) related to WO3.2H2O, phase II, prepared by refluxing LiVWO6 with concentrated HNO3, is isostructural with WO3.1/3H2O. Dehydration of II around 330-degrees-C yields a hexagonal phase (III, a = 7.25(4), c = 7.74(3) angstrom) isotypic with hexagonal WO3. Both land III exhibit redox and acid-base intercalation reactivity characteristic of layered and tunnel structures.

Hydro-mechanical characterization of Barmer 1 bentonite from Rajasthan, India

The conceptual model for deep geological disposal of high level nuclear waste (HLW) is based on multiple barrier system consisting of natural and engineered barriers. Buffer/backfill material is regarded as the most important engineered barrier in HLW repositories. Due to large swelling ability, cation adsorption capacity, and low permeability bentonite is considered as suitable buffer material in HLW repositories. Japan has identified Kunigel VI bentonite, South Korea - Kyungju bentonite, China - GMZ bentonite, Belgium - FoCa clay, Sweden - MX-80 bentonite, Spain - FEBEX bentonite and Canada - Avonseal bentonite as candidate bentonite buffer for deep geological repository program. An earlier study on Indian bentonites by one of the authors suggested that bentonite from Barmer district of Rajasthan (termed Barmer 1 bentonite), India is suited for use as buffer material in deep geological repositories. However, the hydro-mechanical properties of the Barmer 1 bentonite are unavailable. This paper characterizes Barmer 1 bentonite for hydro-mechanical properties, such as, swell pressure, saturated permeability, soil water characteristic curve (SWCC) and unconfined compression strength at different dry densities. The properties of Barmer 1 bentonite were compared with bentonite buffers reported in literature and equations for designing swell pressure and saturated permeability coefficient of bentonite buffers were arrived at. (C) 2013 Elsevier B.V. All rights reserved.

PICES Press, Vol. 12, No. 1, January 2004

The state of PICES science - 2003 (pdf 281 KB) 2003 Wooster Award (pdf 764 KB) The state of the eastern North Pacific through summer 2003 (pdf 448 KB) The Bering Sea: Current status and recent events (pdf 951 KB) The state of the western North Pacific in the first half of 2003 (pdf 684 KB) The status of oceanic zooplankton in the eastern North Pacific (pdf 390 KB) The precautionary approach to the PDO (pdf 976 KB) Photo highlights of PICES XII (pdf 2.79 MB) William G. Pearcy: Renaissance oceanographer (pdf 2.86 MB) KORDI/PICES/CoML Workshop on "Variability and status of the Yellow Sea and East China Sea ecosystems (pdf 785 KB) PICES/IOC Workshop on "Harmful algal blooms - Harmonization of data" (pdf 330 KB) From physics to predators: Monitoring North Pacific ecosystem dynamics (pdf 270 KB) Toward a coast-wide network of Northeast Pacific coastal-ocean monitoring programs - a brief workshop report (pdf 640) PICES publications (pdf 103 KB) PICES calendar (pdf 45 KB)

Taxonomic description of Peridinium lomnickii, P.lomnickii var. splendida and P. wierzejskii [Translation from: Flora Slodkowodna Polski. Tom 4. Cryptophyceae, Dinophyceae, Raphidoiphyceae, p326,328-330. Warsaw, 1974]

This partial translation from a larger paper provides taxonomic descriptions of the dinoflagellates Peridinium lomnickii, P.lomnickii var. splendida and P. wierzejskii. Illustrations are included.

Dangeardia sporapiculata n.sp., the term 'apiculus' and the species limitation of some chytrids [Translation from: Sydowia 16 324-330, 1963]

Taxonomic observations are given on Dangeardia sporapiculata n. sp. Furthermore the term 'apiculus' and the species limitation of some chytrids are being discussed. It is concluded that the newly described species Dangeardia sporapiculata does not fit satisfactorily into the present system of phlyctidiacee, because their characteristics do not agree exactly with any genus.

High responsivity resonant-cavity-enhanced InGaAs/GaAs quantum-dot photodetector for wavelength of similar to 1 mu m at room temperature

The characteristics of a resonant cavity-enhanced InGaAs/GaAs quantum-dot n-i-n photodiode with only a bottom distributed Bragg reflector used as the cavity mirror, are reported. To suppress the dark current, an AlAs layer is inserted into the device structure as the blocking layer. It turns out that the structure still possesses the resonant coupling nature, and makes Rabi splitting discernible in the photoluminescence spectra. The measured responsivity spectrum of the photocurrent shows a peak at lambda = 1030 nm, and increases rapidly as the bias voltage increases. A peak responsivity of 0.75 A/W, or equivalently an external quantum efficiency of 90.3%, is obtained at V-bias = -1.4 V.

MODIFICATION OF POLYTETRAFLUOROETHYLENE BY RADIATION .1. IMPROVEMENT IN HIGH-TEMPERATURE PROPERTIES AND RADIATION STABILITY

Polytetrafluoroethylene (PTFE) has never been reported to form a network structure when subjected to high energy radiation. Results obtained in this work indicates that when irradiation is performed under 330-340-degrees-C in vacuo PTFE can be crosslinked

Effect of parental stock size on F-1 genetic structure in the bay scallop, Argopecten irradians (Lamarck, 1819)

Three F-1 families of the bay scallop, Argopecten irradians, were produced from one, two and 10 individuals. The genetic changes in these populations, which suffered recent and different levels of bottleneck, were analysed using amplified fragment length polymorphism (AFLP) techniques. In the parental stock, a total of 330 bands were detected using seven AFLP primer pairs, and 70% of the loci were polymorphic. All F-1 groups had a significantly lower proportion of polymorphic loci when compared with the initial stock, and loss of the rare loci and reduction in heterozygosity both occurred. The progeny of the larger population (i.e., N=10) exhibited a lesser amount of genetic differentiation compared with the progeny from N=2, which showed lesser differentiation than progeny from N=1. The effective population sizes (N-e) in N=1, 2 and 10 were estimated as 1.50, 1.61 and 2.49. Based on regression analysis, we recommend that at least 340 individuals be used in hatchery populations to maintain genetic variation.

Structure and denaturation of 4-chlorobenzoyl coenzyme A dehalogenase from Arthrobacter sp. strain TM-1

The secondary structure of the trimeric protein 4-chlorobenzoyl coenzyme A dehalogenase from Arthrobacter sp. strain TM-1, the second of three enzymes involved in the dechlorination of 4-chlorobenzoate to form 4-hydroxybenzoate, has been examined. E(mM) for the enzyme was 12.59. Analysis by circular dichroism spectrometry in the far uv indicated that 4-chlorobenzoyl coenzyme A dehalogenase was composed mostly of alpha-helix (56%) with lesser amounts of random coil (21%), beta-turn (13%) and beta-sheet (9%). These data are in close agreement with a computational prediction of secondary structure from the primary amino acid sequence, which indicated 55.8% alpha-helix, 33.7% random coil and 10.5% beta-sheet; the enzyme is, therefore, similar to the 4-chlorobenzoyl coenzyme A dehalogenase from Pseudomonas sp. CBS-3. The three-dimensional structure, including that of the presumed active site, predicted by computational analysis, is also closely similar to that of the Pseudomonas dehalogenase. Study of the stability and physicochemical properties revealed that at room temperature, the enzyme was stable for 24 h but was completely inactivated by heating to 60 degrees C for 5 min; thereafter by cooling at 1 degrees C min(-1) to 45 degrees C, 20.6% of the activity could be recovered. Mildly acidic (pH 5.2) or alkaline (pH 10.1) conditions caused complete inactivation, but activity was fully recovered on returning the enzyme to pH 7.4. Circular dichroism studies also indicated that secondary structure was little altered by heating to 60 degrees C, or by changing the pH from 7.4 to 6.0 or 9.2. Complete, irreversible destruction of, and maximal decrease in the fluorescence yield of the protein at 330-350 nm were brought about by 4.5 M urea or 1.1 M guanidinium chloride. Evidence was obtained to support the hypothetical three-dimensional model, that residues W140 and W167 are buried in a non-polar environment, whereas W182 appears at or close to the surface of the protein. At least one of the enzymes of the dehalogenase system (the combined 4-chlorobenzoate:CoA ligase, the dehalogenase and 4-hydroxybenzoyl coenzyme A thioesterase) appears to be capable of association with the cell membrane.

More nitrogen rich B-type stars in the SMC cluster, NGC 330

High resolution spectra of seven early B-type giant/supergiant stars in the SMC cluster NGC330 are analysed to obtain their chemical compositions relative to SMC field and Galactic B-type stars. It is found that all seven stars are nitrogen rich with an abundance approximately 1.3 dex higher than an SMC main- sequence field B-type star, AV304. They also display evidence for deficiencies in carbon, but other metals have abundances typical of the SMC. Given the number of B-type stars with low projected rotational velocities in NGC330 (all our targets have v sin i <50 km s(-1)), we suggest that it is unlikely that the stars in our sample are seen almost pole-on, but rather that they are intrinsically slow rotators. Furthermore, none of our objects displays any evidence of significant Balmer emission excluding the possibility that these are Be stars observed pole-on. Comparing these results with the predictions of stellar evolution models including the effects of rotationally induced mixing, we conclude that while the abundance patterns may indeed be reproduced by these models, serious discrepancies exist. Most importantly, models including the effects of initially large rotational velocities do not reproduce the observed range of effective temperatures of our sample, nor the currently observed rotational velocities. Binary models may be able to produce stars in the observed temperature range but again may be incapable of producing suitable analogues with low rotational velocities. We also discuss the clear need for stellar evolution calculations employing the correct chemical mix of carbon, nitrogen and oxygen for the SMC.

1,1-Bis(Phenylseleno)-and 1,1-Bis(Methylseleno)- alkyllithiums as building-blocks in organic synthesis

1,1 - Bis(phenylseleno)alkyllithiums are conveniently prepared from the corresponding selenoacetals and lithium tetramethylpiperidide in HMPT/THF.

Die Kosten der Modellabteilung „Schnittkäserei“ am Beispiel der Herstellung von Gouda-Käse. Teil 1: Grundlagen und modellspezifischer Faktoreneinsatz

In dem vorliegenden 1. Teil der Arbeit werden die Grundlagen und der spezifische Faktoreinsatz der Modellabteilung „Schnittkäserei” dargestellt. In den sechs Unterabteilungen Vorstapelung, Bruchbereitung und Pressen, Salzbad, Käsebehandlung und Reifungslager, Abpackung sowie Versandkühlraum und Expedition wird ein rindengereifter Gouda-Käse (12-kg-Laib) hergestellt und hin sichtlich seiner Kostenverursachung untersucht. Zur Bestimmung der Modellkosten wurden vier Modelle gebildet, deren Kapazitäten in der Kesselmilchverarbeitung zwischen 8.000 und 48.000 l/h liegen. In Abhängigkeit vom Beschäftigungsgrad, der für Werte zwischen 21 und 100% simuliert wurde, können so die Kosten für Käsemengen zwischen rd. 5.100 und 30.800 l Käse/Jahr bestimmt werden. Gemäß den vorgegebenen Kapazitäten müssen die technischen Voraussetzungen für die Ausgestaltung der einzelnen Unterabteilungen modellspezifisch festgelegt werden, wobei eine Anpassung der technischen Auslegung an eine verringerte Auslastung bei 33%iger Beschäftigung erfolgt. Diese Arbeit wird fortgesetzt mit dem Teil 2 „Ergebnisse und Interpretation der Modellkalkulationen” in Heft 3 (1993) dieser Zeitschrift.

Die Kosten der Modellabteilung „Weichkäserei“. Teil 1: Grundlagen und Rohstoffmengenrechnung

In dem vorliegenden Teil 1 der Arbeit werden die Grundlagen und die Rohstoffmengenrechnung zur Ermittlung der Modellkosten in der Abteilung Weichkäserei dargestellt. In sechs Unterabteilungen - Vorstapelung, Bruchbereitung und Portionierung, Umhorden/Salzen, Reifung, Abpackung, Fertiglager - werden aus der Produktgruppe Weichkäse die Sorten Camembert 30 und 60 % F.i.Tr. sowie Brie 45 % F.i.Tr. mit unterschiedlichen Stückgewichten hergestellt und diese hinsichtlich ihrer Kostenverursachung untersucht. Zur Kalkulation der Modellkosten werden 4 Modelle gebildet, deren Verarbeitungskapazität an Kesselmilch zwischen 8.000 und 30.000 l/h liegen. In Abhängigkeit vom Beschäftigungsgrad, der für Werte zwischen 15 % und 100 % simuliert wurde, können so Kosten für Käsemengen zwischen rd. 700 und 17.0001 Käse/Jahr bestimmt werden. Da der Rohstoff Milch im kostenrechnerischen Ansatz als der wichtigste Kostenfaktor gilt, wird der verursachungsgerechten Rohstoffverbrauchsbestimmung in diesem Teil ein gesondertes Kapitel gewidmet. Die Arbeit wird mit dem Teil 2 ''Modellspezifischer Faktoreinsatz'' fortgesetzt, dem abschließend der Teil 3 "Ergebnisse und Interpretation der Modellkalkulation" folgt.