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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Sythesis of mesoporous phosphates via solid state reaction at low temperature

Liu, Qi 25 August 2010 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Three parts consist of my thesis work centered on the synthesis of inorganic phosphates and then metal organic frame work (MOF). The first part is the synthesis of mesoporous chromium phosphates using the room temperature solid state reaction (SSR)approach. One of the major aims of this work is to fill the gap of lacking a low cost, low or zero pollution, easy method to synthesize phosphates. The room temperature solid state reaction has been demonstrated in this work is such a method. Mesoporous chromium phosphates were prepared using the solid state reaction at low temperature using CrCl3.6H2O, and NaH2PO4.2H2O as precursors and the surfactant cetyltrimethyl ammonium bromide (CTAB) as template. The synthesized chromium phosphates were characterized by XRD, EDS, HR-TEM, N2-physisorption, TG-DSC and UV-Vis spectroscopies. The results indicate that chromium phosphate mesophases were formed only at atomic ratios of P/Cr ≥ 1.8. The mesophase for P/Cr = 2.0 phosphate possessed the highest ordering of pore array, with a specific surface area as high as 250.78 m2/g and an average pore size of 3.48nm. The catalytic performance of the chromium phosphates was examined by employing a model reaction, namely the dehydration of isopropanol to propene. The results indicated that all synthesized chromium phosphates exhibited significantly higher isopropanol conversions and propene yields than that synthesized via the conventional precipitation route. The highest propene selectivity (96.43%) at the highest isopropanol conversion (93.10%) has been obtained over the mesoporous chromium phosphate catalyst synthesized with a P/Cr atomic ratio of 2.0. The formation mechanism of the mesoporous chromium phosphate was investigated by FTIR technique.The results show that CTAB template plays a key role in the formation of mesoporous chromium phosphates. Mesoporous lithium manganese phosphates were also successfully synthesized using the same approach of solid state reaction (SSR) at low temperature by using LiC2O3.6H2O, MnCl2.6H2O and NH4H2PO4.2H2O as precursors and the surfactant cetyltrimethyl ammonium bromide (CTAB) as template. The synthesized lithium manganese phosphates were characterized by XRD, EDS, SEM, HR-TEM, N2-physisorption. The results show that the synthesized meoporous lithium manganese phosphates exhibited a high specific surface area (256.63 m2/g) and a narrow pore size distribution. The electrochemical tests of Li-ion batteries were performed and the results show that the charge voltage could increase to be 3.60 V while the first time discharge capacity could be as high as 100 mAh/g. The Nitro-Cu-MOF complexes, a new class of metal organic frameworks, have been successfully synthesized using a conventional thermal reaction. The obtained Nitro-Cu-MOFs have a specific surface area of 576.27 m2/g and a pore volume of 0.32 m3/g.The gas uptake of the obtained Nitro-Cu-MOFs at 60 psi is 68 mg/g (sorbate/sorbent) at 298 K for carbon dioxide, which is much higher than that of the Cu-MOFs, 31 mg/g at 298 K for carbon dioxide.
122

The effects of an organic phosphate compound (Bayer 21

Milleret, Roy Joseph. January 1959 (has links)
Call number: LD2668 .T4 1959 M55
123

The Physico-Chemical Relationships of Soil Phosphates

Buehrer, T. F. 30 June 1932 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
124

Electrodialysis as a Measure of Phosphate Availability in Soils and the Relation of Soil Reaction and Ionization of Phosphates to Phosphate Assimilation

McGeorge, W. T. 01 March 1932 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
125

Coincident signalling between G←q- and G←i←/←o-coupled receptors to elevate [Ca'2'+]←i

Yeo, Alison January 1999 (has links)
No description available.
126

Group 4 and group 5 alkoxides containing oxophosphorus (V) ligands

Willett, Kathryn Joyce January 2001 (has links)
No description available.
127

The application of flow methodology to microwaved enhanced reactions

Williams, Kathleen Elizabeth January 1995 (has links)
No description available.
128

Cloning and characterisation of a novel 72 kDa inositol polyphosphate 5-phosphatase

Kong, Anne Mandy, 1973- January 2001 (has links)
Abstract not available
129

Arginine-specific negative regulation of Neurospora crassa arg-2 mediated by the arg-2 uORF and Arginine

Carroll, Julie Marie 06 1900 (has links) (PDF)
M.S. / Molecular Biology / Neurospora crassa arg-2 encodes the small subunit of Arg-specific carbamoyl phosphate synthetase and is negatively regulated by arginine. This regulation is mediated by a 24-codon upstream open reading frame (uORF). The sequence of this uORF is critical for Arg-specific regulation. Six mutated templates were used to examine which residues of the uORF are important for this regulation. Mutations were created using megaprimer PCR and a luciferase gene was used as a reporter in the in vitro translation studies. Mutations of Asp 12, Asp 16, and Ser 10 eliminate Arg-specific regulation. Leaky scanning is thought to be involved, and a hypothetical ribosome stalling model that mediates Arg-specific attenuation of translation is proposed.
130

Detection of inositol phosphates with HPLC-ICP-AES : Method development

Wintergerst, Mieke January 2013 (has links)
Inositol phosphates (IPs) represent a major part of the organic phosphorus found in the environment, which makes their identification and quantification very important. The goal of this project was to explore the possibility of quantification of IPs with inductively coupled plasma - atomic emission spectrometry (ICP - AES). This paper deals with the creation of an in-house IP standard and the considerations for the successful linking of high performance liquid chromatography (HPLC) with ICP - AES. Experiments with different nebulizers, mobile phases, standard solutions and model substance were performed. The proposed optimal conditions for the ICP experiments are: the use of a modified Lichte nebulizer, mobile phase without methanol and the use of standards matched to the mobile phase. Adenosine monophosphate (AMP) was found to be a good model substance and showed that the band broadening from HPLC to ICP – AES was approximately a factor of 2. Limits of detection for AMP were 5 µM for HPLC and 20 µM for ICP – AES. The optimal way to create an in-house standard was using the potassium salt of IP6 and treating it for 90 minutes at a temperature of 120 ºC with 3.2 M acetic acid.

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