Search Results - (Author, Cooperation:D. Chakrabarty)

2014-10-10

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

2018-02-16

Wiley-Blackwell

0148-0227

Geosciences

Physics

1439-0523

Blackwell Publishing Journal Backfiles 1879-2005

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Rooted cuttings of Dendranthema grandiflorum cv. ‘Puja’ were treated with different doses of gamma rays. Sectorial somatic mutations both in flower colour and shape were detected in all the doses. The original floret colour of ‘Puja’ is red-purple and florets are flat spoon shaped. One of the mutant floret colour was yellow-orange with original flat florets and another mutant floret colour was yellow-orange with tubular florets. Original and mutated ray florets were cultured on agar-solidified Murashige and Skoog basal medium supplemented with sucrose and different combinations of 1-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP). Direct shoot organogenesis was seen within 2 weeks of culture initiation. The best regeneration was obtained on medium supplemented with 1 mg/l BAP + 0.5 mg/l NAA. Shoots regenerated from all explant types were rooted in vitro and transferred to the field. Regenerated plants flowered true-to-explant floret colour and shape. The isolated yellow floret colour mutants and yellow floret colour mutants with tubular florets were maintained vegetatively and have proved to be true to type in two successive generations.

Electronic Resource

1365-2109

Blackwell Publishing Journal Backfiles 1879-2005

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Growth performances of advanced fry of Indian major carps. Labeo rohita (Hamilton). Catla catla (Hamilton) and Cirrhinus mrigala (Hamilton), were examined in simulated pond systems using monthly application of the following fertilizers in six treatments: Mussoorie rockphosphate (MPR) in low (100 kg P2O5 ha−1) and high doses (200 kg P2O5 ha−1), single superphosphate (SSP) (50 kg P2O5 ha−1), single superphosphate mixed with rockphosphate (1:1 by weight: 50 kg P2O5), compost (C) (water hyacinth and cattle manure) and composted rockphosphate (MPR-C). The amount of available P in surface sediment of MPR-C did not differ from that in either the SSP or the MPR + SSP treatment, whereas the total and available N contents differed greatly. There was an inverse relationship between the time to reach phosphate peak of water and the retention time of fertilizer in surface sediments. It is evident that total P of surface sediment was the most significant contributor to fish growth in exclusively MPR treatments, whereas total P and total N of surface sediments are involved in the MPR treatments in combination with compost or SSP.

Electronic Resource

1439-0426

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Thirty-two glass jars (3 L each) in the laboratory and outdoor tanks (300 L) were used to examine the influence of common carp (Cyprinus carpio L.) in increasing the fertilizer value of phoshate rock in eight treatment combinations in quadruplicate. Input of water soluble hosphate was determined to quantify the effects of bioturbation, fish excrements and soil. The level of orthophosphate in water was always lowest in the control series. Introduction of common carp fry resulted in a net increase of 0.1 to 0.114 mg. L-1 of orthophosphate attributable to the effect of fish excrement. Bioturbation caused by common carp resulted in as high as a 72 to 100 % influx of phosphate from bottom soil in the presence of phosphate rock but only about 7 to 8 % in the absence of phosphate rock.〈section xml:id="abs1-2"〉〈title type="main"〉Zusammenfassung Die Bedeutung eingesetzter Karpfen (Cyprinus carpio L.) zur Steigerung des Düngerwertes von Phosphatgestein32 Glasgefäße (3 L Volumen) wurden im Labor und 4 Behälter (300 L) im Freien aufgestellt urn den Einfluß zunehmender Düngung durch Phosphatgestein auf Karpfen (Cyprinus carpio L.) in 8 unterschiedlichen Applikationen mit jeweils 4 Replikaten zu testen. Der Eintrag wasserloslichen Phosphats wurde bestimmt, urn die Wirkung von Bioturbation, Fischexkrementen und Bodensubstrat zu prüfen. Die Konzentration an Orthophosphat war in den Kontrollen am niedrigsten. Das Einsetzen von Karpfen-Jungfischen erhöhte die Nertozunahme des Orrhophosphats auf 0,1 bis 0,114 mg. -1 und diese Zunahme muß den Ausscheidungen der Fische zugeschrieben werden. Die durch die Karpfen verursachte Bioturbation resultiene in einer 72 bis 100% igen Zunahme des Influx des Phosphats aus dem Bodensubstrat wenn Phosphatgestein dem Boden zugegeben wurde, wahrend dieser Wert nur 7–8%) ohne Phosphatgestein betrug.

Electronic Resource

0022-328X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0022-328X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0022-328X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0022-328X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

0022-328X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Electronic Resource

1572-879X

Cu-Zn-Al catalyst ; hybrid catalyst ; hydrotalcite ; methanol synthesis ; synthesis of C2-C4 hydrocarbons ; zeolites

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract A copper-zinc-aluminum methanol synthesis catalyst has been prepared using a precipitated hydrotalcite-type precursor that decomposes to a mixture of the corresponding amorphous oxides at a low temperature. TPR studies show that such a mixture is easy to reduce giving a highly dispersed catalyst. When this is mixed with a zeolite, the resulting hybrid catalyst gives C2-C4 hydrocarbons with very high selectivity. This may be useful in obtaining LPG from synthesis gas.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] The relativistic plasma flows onto neutron stars that are accreting material from stellar companions can be used to probe strong-field gravity as well as the physical conditions in the supra-nuclear-density interiors of neutron stars. Plasma inhomogeneities orbiting a few kilometres above the ...

Electronic Resource

1573-5060

chimera ; chrysanthemum ; mutation breeding ; regeneration

Springer Online Journal Archives 1860-2000

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract Rooted cuttings of white flowered cv. `Purnima' and red flowered cv. `Colchi Bahar' of Chrysanthemum morifolium were treated with gamma rays. Sectorial somatic mutations in flower colour were detected in both the cvs. Mutated ray florets (yellow colour for both the cvs) were cultured on agar-solidified Murashige & Skoog basal medium supplemented with sucrose and different combinations of BAP/kinetin and NAA. Direct shoot organogenesis was noticed within 2 weeks of culture initiation. SEM studies confirmed this direct shoot differentiation. The best regeneration was obtained on medium supplemented with 0.2 mg/l NAA and 0.5 mg/lBAP. Shoots regenerated from mutated ray florets were rooted in vitro and transferred to the field. These plants flowered true-to-explant floret colour and shape. These isolated yellow mutants were maintained vegetatively have proved to be true-to-type in two successive generations.

Electronic Resource

1573-0662

Stratosphere ; spherical probe ; recombination coefficient ; ion-composition ; ion density ; exothermic reaction ; Gerdien condenser

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Geosciences

Abstract There has been a considerable improvement in the knowledge of stratospheric positive ion chemistry during the last decade. Results of several in-situ measurements of ion composition have been reported. Total ion density has also been measured with greater accuracy. In this work, theoretical study has been made to reproduce the main features of the above observations. Difficulties encountered in such studies are discussed. Finally models of total ion density and ion composition are given.

Electronic Resource

1573-5044

chimera ; Chrysanthemum morifolium ; gamma irradiation ; shoot regeneration ; somatic mutation

Springer Online Journal Archives 1860-2000

Biology

Abstract Rooted cuttings of Chrysanthemum morifolium cv. Maghi, a small flowered, late blooming cultivar, were treated with different doses of gamma rays. Somatic mutations in flower colour (light mauve, white, light yellow and dark yellow) and chlorophyll variegation in leaves were detected as chimeras in treated populations. Attempts were made to standardize a microtechnique for plant regeneration from mutated tissues of stem node, stem internode, shoot tip and ray floret. All these explants were cultured on Murashige and Skoog's medium with 3% sucrose, 0.8% agar and different concentrations and combinations of growth regulators. Plant regeneration was successful from all of the mutated tissues. Plants with chlorophyll variegation in leaves and two new flower colours (light mauve and white) were isolated in pure form with 64% and 100% efficiency of mutant recovery, respectively. Attempts are being made to use this technique to establish new varieties from chimeric tissues to meet the increasing demand of the floriculture trade.

Electronic Resource

1573-4803

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract Crystallization and ageing of pure ammonium nitrate crystals was studied by scanning electron microscopy. Ageing the crystals beyond 1 h led to the growth of secondary grains along the grain boundaries of primary grains (140–200 μm). After 6 h ageing secondary growth along grain boundaries was not observed; instead, distinct clusters with morphologies similar to the secondary grains were formed. The ancillary growth obeys approximately the parabolic relation L=(Kt)1/n+1 where n=1 justifies grain growth in the pure crystals, and its formation is ascribed to the dissolution of dendrites, edges and corners. The high interfacial activity and interparticle voids can affect the storage and mechanical properties of the material.

Electronic Resource

1588-2837

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract Были приготовлены образцы окиси никеля, насышенные литием и индием, с содержанием допанта до 3 ат.%-ов. Были исследованы электрические свойства этих образцов. Для всех образцов была обнаружена проводимость типа р, которая возрастает с литиевым насыщением и уменышается с индиевым насыщением. Дегидрирование 2-пропанола на этих катаизаторах уменьшается с увеличением концетрации дырок в твердом веществе. Ступенью, лимитирующей скорость процесса, является десорбция ацетона. Предлагается вероятный менанизм протекания процесса.

Abstract Lithium and indium doped nickel oxide samples have been prepared with up to 3 at. % of dopant. The electrical properties of these samples have been studied. All the samples exhibit p-type conductivity which increases with lithium doping and decreases upon doping with indium. Dehydrogenation of 2-propanol on these catalysts increases with the hole concentration in the solid. Desorption of acetone appears to be the rate-determining step. A possible mechanism for the reaction is proposed.

Electronic Resource

1588-2837

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract Рутениевые каталиэаторы на носителе Al2O3, приготовленные иэ Ru3(CO)12, были исследованы с помощью ИК и рентгеновской фотоэлектронной спектпоскопии (XPS). Триатомный кластер эадерживается на носителе, но при 150°C отщепляется. Для полного удаления карбонильных групп требуется наг⌕ев при 350°C в вакууме. XPS исследования укаэывают на то, что раэложившийся каталиэатор при дальнейшем восстановлении в H2 при 400°C уже не иэменяется. Атомы рутения остаются эахваченными в порах носителя.

Abstract A supported ruthenium catalyst on alumina prepared from Ru3(CO)12 has been studied by infrared and X-ray photoelectron spectroscopy (XPS). The triatomic cluster is retained on the support but breaks down at 150°C. Complete elimination of the carbonyl groups requires heating at 350°C under vacuum. XPS studies show that the decomposed catalyst does not change on further reduction in H2 at 400°C. The ruthenium atoms remain trapped within the pores of the support.

Electronic Resource

1588-2837

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract Разложение изопропанола на V2O5 и бронзах: Li0,02V2O5, Na0,02V2O5, Na0,06V2O5, Li0,33V2O5 и Na0,33V2O5 было исследовано в области температур 186–300°C. Для первых четырех катализаторов основной реакцией оказалась дегидратация до пропена с незначительной дегидрогенизацией до ацетона. Дегидратация на этих катализаторах увеличивается с содержанием щелочного металла, а энергия активации остается неизменной. На последних двух катализаторах дегидратация и дегидрогенизация протекают при сравнимых скоростях. Исходя из влияния продуктов на начальную скорость, данных электропроводимости катализаторов и их ЭПР спектров, предлагается механизм дегидратации изопропанола.

Abstract Decomposition of isopropanol on V2O5 and the bonzes Li0.02V2O5, Na0.02V2O5, Na0.06V2O5, Li0.33V2O5, and Na0.33V2O5 has been studied in the temperature range 168–300°C. The main reaction was found to be dehydration to propene with negligible dehydrogenation to acetone on the first four catalysts. Dehydration on these catalysts increased with the alkali metal content, but the energy of activation remained unchanged. On the last two catalysts, dehydration and dehydrogenation proceeded at comparable rates. A tentative mechanism for the dehydration of isopropanol is proposed, based on the effect of the product on the initial rate, the electric conductivity of the catalysts and their ESR spectra.

Electronic Resource

1588-2837

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Abstract Каталитическое окисление CO исследовано на Nd1−xBaxCoO3 и LnCoO3 (Ln=La, Sm, Nd, Dy). Каталитическую активность сравнивали с изменением х, кхслородных дефектов и со структурнями изменениями. Найдено, что соединехия с кубической структурой дают максимальную активность, которая уменьшается в направлении от кубической структуры. Это объясняют лучшей делокализацией d-электронов кобальта кубических соединений.

Abstract Catalytic oxidation of CO has been studied on Nd1−xBaxCoO3 and LnCoO3 (Ln=La, Sm, Nd, Dy). Catalytic activity was compared with changing x, oxygen defects and structural changes. It has been found that compounds with cubic structure show maximum activity, which decreases with deviation from cubic structure. This has been explained as due to better delocalization of the d-electrons of cobalt in the cubic compounds.

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