1,721,336 research outputs found
MODIFICATION OF INULINE BY IODIC ACID
Full text linkIn order to further modify inulin with drugs, the process of introducing reactive aldehyde groups into the inulin macromolecule was carried out. Aldehyde groups were introduced by oxidizing inulin with iodic acid. The process of oxidation of inulin and cellulose with iodic acid was compared. The quantities of aldehyde groups in the oxidized samples were estimated, their molecular weights were determined, IR spectra were measured, the iodine number of the inulin dialdehyde and their oxidation state were determined
Important Routes for Methanediol Formation by Formaldehyde Hydrolysis Catalyzed by Iodic Acid and for the Contribution to an Iodic Acid Sink by the Reaction of Formaldehyde with Iodic Acid Catalyzed by Atmospheric Water
No full textMethanediol
formed by the hydrolysis of formaldehyde is an important
intermediate in the formation of formic acid in the atmosphere. However,
the formation of methanediol by the direct reaction of formaldehyde
(HCHO) with water (H2O) is not feasible in the gas phase
in the atmosphere due to the very high enthalpy of activation at 0
K for the HCHO + H2O reaction. Here, by using quantum chemical
methods and reaction rate theory, we report a new mechanistic route
for the iodic acid-catalyzed gas-phase hydrolysis of formaldehyde.
The present findings show that iodic acid serves as an excellent catalyst
in this reaction, decreasing the enthalpy of activation at 0 K from
36.01 kcal/mol for the HCHO + H2O reaction to −13.28
kcal/mol for the HCHO + H2O + HIO3 reaction
with respect to the separate reactants. Additionally, the calculation
results also show that water can catalyze the HCHO + HIO3 reaction, decreasing the enthalpy of activation at 0 K for the HCHO
+ HIO3 reaction from 2.96 to −10.00 kcal/mol. The
calculated kinetics results reveal that the gas-phase hydrolysis of
formaldehyde catalyzed by iodic acid can make a substantial contribution
to the sink of formaldehyde and the formation of methanediol below
260 K. The reaction of formaldehyde with iodic acid catalyzed by water
dominates over the HIO3 + OH reaction under full atmospheric
conditions. The present findings are expected have broad implications
for understanding the formation of methanediol and the sink of formaldehyde
and iodic acid in the atmosphere
Effects of compression on the halogen bonding of iodic acid – a neutron diffraction study
Full text linkThe response of the crystallographic structure of iodic acid has been determined using neutron diffraction up to 7.2 GPa. We observe no evidence of a direct structural phase transition. However, we do observe evidence of a molecular re-orientation, previously suggested by a high pressure experimental Raman study and computational study. We show how the crystal structure responds to the application of pressure and observe an increased extent of the halogen-bonding interactions
Condition of Iodic, Hydrofluoric and Chromic Acids and their Salts in Aqueous Solution.
No full textCondition of Iodic, Hydrofluoric and Chromic Acids and their Salts in Aqueous Solution
Synthesis of new hydroxyacetophenones by using iodine and iodic acid
No full textP. G. Department of Chemistry, Yeshwant Mahavidyalaya, Nanded-431 602, India
Manuscript received 18 August 1999, revised 3 February 2000, accepted 23 February 2000
Iodine and iodic acid mixture has been used as a reagent for iodination of hydroxyacetophenones, and some new hydroxy· iodoacetophenones are prepared
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Effective ‘non-aqueous hydrolysis’ of oximes with iodic acid in dichloromethane under mild, heterogeneous conditions
No full textKetoximes and aromatic aldoximes are converted to the corresponding carbonyl compounds in excellent yields (67–97%), upon treatment with a suspension of iodic acid in dry at room temperatur
Intercalation of Iodic Acid into the Layered Uranyl Iodate, UO<sub>2</sub>(IO<sub>3</sub>)<sub>2</sub>(H<sub>2</sub>O)
No full textThe direct intercalation of iodic acid into the layered uranyl iodate,
UO2(IO3)2(H2O), has been observed to yield UO2(IO3)2(H2O)·2HIO3
in crystalline form. This is the first example of this type of reaction
with iodic acid
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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