XAFS and IR Studies on Luminescent Silver Zeolites

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

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ChemInform Abstract: NMR AND IR STUDIES OF THE BONDING PROPERTIES OF THE ETHYLENE-RHODIUM COMPLEXES RHCL(C2H4)(L)(L′) (L = C2H4, CO, PR3, L′ = 2,6-LUTIDINE)

Chemischer Informationsdienst ◽

10.1002/chin.197847290 ◽

1978 ◽

Vol 9 (47) ◽

Author(s):

A. MAISONNAT ◽

R. POILBLANC

Keyword(s):

Rhodium Complexes ◽

Ir Studies ◽

Bonding Properties

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Formulation and evaluation of bi-layer floating tablets of ziprasidone HCl and trihexyphenidyl HCl

Brazilian Journal of Pharmaceutical Sciences ◽

10.1590/s1984-82502011000300012 ◽

2011 ◽

Vol 47 (3) ◽

pp. 545-553 ◽

Cited By ~ 2

Author(s):

Sathis Kumar Dinakaran ◽

Santhos Kumar ◽

David Banji ◽

Harani Avasarala ◽

Venkateshwar Rao

Keyword(s):

Sustained Release ◽

In Vitro Release ◽

Chemical Properties ◽

Matrix Tablets ◽

In Vitro Dissolution ◽

Floating Tablets ◽

Ir Studies ◽

Weight Variation ◽

The Matrix

The purpose of this research study was to establish ziprasidone HCl NR 40 mg and trihexyphenidyl HCl SR 4mg in the form of bi-layer sustained release floating tablets. The tablets were prepared using sodium HPMC K4M / HPMC K15M as bio-adhesive polymers and sodium bicarbonate acting as a floating layer. Tablets were evaluated based on different parameters such as thickness, hardness, friability, weight variation, in vitro dissolution studies, content of active ingredient and IR studies. The physico-chemical properties of the finished product complied with the specifications. In vitro release from the formulation was studied as per the USP XXIII dissolution procedure. The formulations gave a normal release effect followed by sustained release for 12 h which indicates bimodal release of ziprasidone HCl from the matrix tablets. The data obtained was fitted to Peppas models. Analysis of n values of the Korsmeyer equation indicated that the drug release involved non-diffusional mechanisms. By the present study, it can be concluded that bi-layer tablets of ziprasidone HCl and trihexyphenidyl HCl will be a useful strategy for extending the metabolism and improving the bioavailability of Ziprasidone HCl and Trihexyphenidyl HCl.

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Oxidation of Ethanol in Cu-Faujasites Studied by IR Spectroscopy

Molecules ◽

10.3390/molecules26092669 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2669

Author(s):

Łukasz Kuterasiński ◽

Jerzy Podobiński ◽

Jerzy Datka

Keyword(s):

Ethanol Oxidation ◽

Produced Water ◽

Acid Sites ◽

No Adsorption ◽

Ir Studies ◽

Oxygen Donor ◽

Before And After ◽

Acetate Formation ◽

Back Donation

In this study, IR studies of the coadsorption of ethanol and CO on Cu+ cations evidenced the transfer of electrons from ethanol to Cu+, which caused the lowering of the frequency of the band attributed to CO bonded to the same Cu+ cation due to the more effective π back donation of d electrons of Cu to antibonding π* orbitals of CO. The reaction of ethanol with acid sites in zeolite HFAU above 370 K produced water and ethane, polymerizing to polyethylene. Ethanol adsorbed on zeolite Cu(2)HFAU containing acid sites and Cu+exch also produced ethene, but in this case, the ethene was bonded to Cu+ and did not polymerize. C=C stretching, which is IR non-active in the free ethene molecule, became IR active, and a weak IR band at 1538 cm−1 was present. The reaction of ethanol above 370 K in Cu(5)NaFAU zeolite (containing small amounts of Cu+exch and bigger amounts of Cu+ox, Cu2+exch and CuO) produced acetaldehyde, which was further oxidized to the acetate species (CH3COO-). As oxygen was not supplied, the donors of oxygen were the Cu species present in our zeolite. The CO and NO adsorption experiments performed in Cu-zeolite before and after ethanol reaction evidenced that both Cu+ox and Cu2+ (Cu2+exch and CuO) were consumed by the ethanol oxidation reaction. The studies of the considered reaction of bulk CuO and Cu2O as well as zeolites, in which the contribution of Cu+ox species was reduced by various treatments, suggest that ethanol was oxidized to acetaldehyde by Cu2+ox (the role of Cu+ox could not be elucidated), but Cu+ox was the oxygen donor in the acetate formation.

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International Relations Studies in China

Journal of East Asian Studies ◽

10.1017/s1598240800000679 ◽

2002 ◽

Vol 2 (1) ◽

pp. 69-87 ◽

Cited By ~ 1

Author(s):

Jianwei Wang

Keyword(s):

Social Science ◽

International Relations ◽

Academic Discipline ◽

Political Control ◽

Degree Programs ◽

Teaching And Research ◽

Intellectual Community ◽

Ir Studies ◽

Western Intellectual

This article traces the evolution of international relations studies as an academic discipline in China in the last two decades or so. Almost non-existent before the 1980s, IR studies has become an increasingly dynamic, sophisticated, and popular field of social science in both teaching and research. This is reflected in the growth of institutions, degree programs, scholarship and paradigmatic debate as well as interaction with the Western intellectual community in both theory and personnel. Nevertheless, the development of IR studies in China is still in its primitive stage and it must contend with various problems such as political control, a lack of well-trained scholars, inadequate funding, and ideational uncertainty.

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Modification of Point Defects in Quartz for Device Applications

MRS Proceedings ◽

10.1557/proc-24-445 ◽

1983 ◽

Vol 24 ◽

Author(s):

J. C. King ◽

D. R. Koehler

Keyword(s):

Frequency Control ◽

Defect Center ◽

Ir Studies ◽

Device Applications ◽

Temperature Ranges ◽

Radiation Induced ◽

Impurity Centers ◽

Acoustic Loss ◽

Quartz Crystal Resonators ◽

Hostile Environments

ABSTRACTImpurity centers in quartz play a significant role in the behavior of precision crystal resonators subjected to ionizing radiation. The substitutional Al center, charge compensated by Na, Li, H or a hole, is now known to be the primary contributing factor in most radiation-induced effects. Acoustic loss measurements, ESR measurements, optical studies and IR studies of these defects, over extended temperature ranges, have contributed substantially to our understanding of the impurity centers' role. Radiation-induced frequency and acoustic loss changes in quartz crystal resonators are now understood in terms of the evolving character of the defect center in a radiation field. This understanding has prompted material modification efforts such as high temperature electrolysis and doping technologies which permit, for instance, the fabrication of frequency control devices that are little affected by hostile environments.

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From the Colonial to Feminist IR: Feminist IR Studies, the Wider FSS/GPE Research Agenda, and the Questions of Value, Valuation, Security, and Violence

Politics & Gender ◽

10.1017/s1743923x17000484 ◽

2017 ◽

Vol 13 (04) ◽

pp. 739-746 ◽

Cited By ~ 4

Author(s):

Anna M. Agathangelou

Keyword(s):

Political Economy ◽

International Relations ◽

Research Agenda ◽

International Politics ◽

Security Studies ◽

Global Political Economy ◽

Personal Lives ◽

Ir Studies ◽

The World ◽

Forms Of Violence

International relations (IR) feminists have significantly impacted the way we analyze the world and power. However, as Cynthia Enloe points out, “there are now signs—worrisome signs—that feminist analysts of international politics might be forgetting what they have shared” and are “making bricks to construct new intellectual barriers. That is not progress” (2015, 436). I agree. The project/process that has led to the separation/specialization of feminist security studies (FSS) and feminist global political economy (FGPE) does not constitute progress but instead ends up embodying forms of violence that erase the materialist bases of our intellectual labor's divisions (Agathangelou 1997), the historical and social constitution of our formations as intellectuals and subjects. This amnesiac approach evades our personal lives and colludes with those forces that allow for the violence that comes with abstraction. These “worrisome signs” should be explained if we are to move FSS and FGPE beyond a “merger” (Allison 2015) that speaks only to some issues and some humans in the global theater.

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