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Item Controlled Hydrolysis of TiO2 from HCl Digestion Liquors of Ilmenite(American Chemical Society, 2022-05-18) Haverkamp RG; Wallwork KS; Waterland MR; Gu Q; Kimpton JATraditionally, industrial scale production of the TiO2 pigment is achieved by hydrolysis from H2SO4 solution or by hydrolysis of TiCl4. However, the H2SO4 route produces FeSO4 waste, which is problematic, and the TiCl4 route requires a high grade rutile feedstock or chemically upgraded ilmenite (FeTiO3). Here, we investigate a direct route from ilmenite to TiO2 using aqueous HCl. New Zealand ilmenite digested in 35 wt % HCl to achieve a solution containing typically 1.18 mol kg-1 Fe(aq)2+ and 1.14 mol kg-1 Ti(aq)4+ was hydrolyzed under reflux, after seed preparation in water, or with phosphoric or citric acid. The structure of the seed was determined by Raman spectroscopy and X-ray powder diffraction using pair distribution function analysis, the latter enabling the identification of short-range order in poorly crystalline materials. TiO2 hydrate was precipitated from HCl in either the anatase or the rutile structure. Unlike from H2SO4, the natural structure formed without the use of structure determining agents is rutile. However, seed preparation using 0.4 mol H3PO4 per mole of Ti (resulting in 0.35 wt% H3PO4 in the hydrate) results in anatase hydrate formation. Sodium citrate or citric acid addition also seed anatase hydrate. The mechanism for polymorph control may be kinetic rather than a structural template or surface adsorption. This process has the potential to be used for the commercial scale production of the TiO2 pigment. Anatase hydrate has the advantage that traces of iron may be more readily removed by washing than from rutile precipitate, making the HCl process from ilmenite feasible for pigment grade material.Item Biochemical profile of heifers with spontaneous humeral fractures suggest that protein-energy malnutrition could be an important factor in the pathology of this disease.(2023-01) Wehrle-Martinez A; Dittmer KE; Back PJ; Rogers CW; Lawrence KCASE HISTORY: Serum and liver samples from 35, 2-year-old dairy heifers that had fractured one or both humeri post-calving between July and December 2019 were submitted to a diagnostic laboratory for analysis. Serum samples were analysed for albumin, β-hydroxybutyrate (BHB), creatinine, Ca, Mg, phosphate, non-esterified fatty acids (NEFA), and serum Cu concentration. Liver samples were analysed for liver Cu concentration. Data were compared to published reference intervals. Data values for heifers that prior to fracture had grazed fodder beet were also compared to values for those that had grazed pasture. CLINICAL FINDINGS: Sixty-nine percent of heifers with humeral fracture had serum creatinine concentrations below the lower value of the reference range (55-130 µmol/L). In 3/32 (9%) heifers, serum NEFA concentrations were increased above the reference value indicating body fat mobilisation (≥1.2 mmol/L for peri-partum cows) and in 20/35 (57%) heifers BHB serum concentrations were above the reference value indicating subclinical ketosis (≥1.1 mmol/L for peri-partum cows). In 24/35 (69%) heifers, liver Cu concentration was low (≤ 44 µmol/kg) or marginal (45-94 µmol/kg). The concentration of Cu in serum was low (≤ 4.5 µmol/L) in 2/33 (6%) heifers and marginal (4.6-7.9 µmol/L) in 5/33 (15%) heifers. There was moderate positive correlation between the logged concentrations of Cu in paired liver and serum samples, r(31) = 0.43; (95% CI = 0.1-0.79; p = 0.014). One heifer had a serum phosphate concentration below the lower limit of the reference range (< 1.10 mmol/L). For all heifers, the concentrations of albumin, Ca, and Mg in serum were within the reference intervals (23-38 g/L, 2.00-2.60 mmol/L, and 0.49-1.15 mmol/L respectively). Over winter, 15/35 (43%) heifers grazed predominantly pasture, 14/35 (40%) grazed fodder beet and 6/35 (17%) had a mixed diet. CLINICAL RELEVANCE: In some of these heifers with humeral fractures, there was evidence for protein and/or energy malnutrition in the form of elevated NEFA and BHB concentrations and low creatinine concentrations in serum. Liver Cu concentrations were also reduced in most affected heifers. However, the absence of a control group means it is not possible to determine if these are risk factors for fracture or features common to all periparturient heifers. Clinical trials and molecular studies are needed to determine the true contribution of Cu and protein-energy metabolism to the pathogenesis of spontaneous humeral fractures in dairy heifers. ABBREVIATIONS: BHB: ß-hydroxybutyrate; NEFA: Non-esterified fatty acids.Item Laboratory study on the fate and reactivity of phosphate added to yellow brown pumice soils : thesis ... M. Agr. Sc.(Massey University, 1965) Chuah, Hong-HeeVolcanic ash blankets almost two-thirds of the North Island (Baumgart 1954). Of the volcanic ash soils, rather more than one third are classified as yellow brown pumice soils (Baumgart 1954) derived from rhyolitic pumiceous ash having clay fractions made up principally of allophane (Fieldes and Taylor 1961). This mineral shows a considerable capacity for fixing phosphate (Jackman 1951). Yellow brown pumice soils present an interesting field of research for the soil scientist, since they are among the most dynamic of soils- their equilibrium with the envirorunent is quite unstable (Baumgart 1954). An attempt is being made in New Zealand to bring the yellow brown pumice soils to a high level of production through both foresting and agriculture. Phosphate topdressing is essential for establishment and maintenance of improved pastures. It appears from the results of Jackman (1955) that a substantial proportion of fertilizer phosphate becomes converted to organic forms and accumulates as such. He has shown also that these soils in the virgin state contain a high proportion of their total phosphorus in the organic form. [From Introduction]Item Sorption and desorption of inorganic phosphate by soils as influenced by inorganic and organic anions : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science (Soil Science) at Massey University(Massey University, 1975) Earl, Keith DavidAnions play a very significant role in the retention and plant availability of soil and fertilizer inorganic phosphate (P). Evidence that different inorganic and organic anions can modify P retention was presented by many workers prior to 1950 ( Kurtz et al., 1946; Dean and Rubins, 1947; Swenson et al., 1949 ). The exact mechanisms of this effect was little understood. In addition, a range of chemical extractants have been used to assess the available P status of soils; these included citrate, tartrate, fluoride, arsenate, and other anions capable of forming stable complexes with Fe and Al in soils. It is now well recognised that microorganisms and root excretions greatly modify the chemical environment in the rhizosphere. Organic compounds found in the root exudates of several plants ( reviewed by Rovira, 1965 ), and produced by microorganisms, include many organic acids known to form strong complexes with metal ions. Such compounds may be an important factor affecting the mobility of P in soils. [FROM INTRODUCTION]Item The relative significance of iron-binding and aluminium-binding of phosphate in soils representative of the main New Zealand genetic groupings as revealed by fractionation methods and by phosphate fixation studies in the laboratory : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science (Horticulture)(Massey University, 1962) Goh, Kuan MAlthough a great body of evidence points to the presence of Iron - and aluminium - bound phosphate in soils as products of the phosphate fixation prooess, until recently no satisfactory procedures have been available for the quantitative assessment of the amounts of these forms in soils. Chang and Jackson (1957) were the first workers to propose a scheme of phosphate fractionation, which included the separate determination of iron - and aluminium - bound phosphates. The limitations of their procedure have been discussed by Fife (1959a, 1959b and 1962), who has proposed (1962) a modified method for the determination of the aluminium - bound soil phosphate fraction. Fife (unpublished results) has subsequently incorporated this procedure into a general scheme of soil phosphate fractionation, which includes the selective determination of iron - bound and calcium - bound phosphates.[FROM INTRODUCTION]Item The phosphate status of the soils of Riverhead forest in relation to growth of Radiata pine : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Soil Science at Massey University(Massey University, 1968) Ballard, RussellExtensive plantations of exotic softwood species in New Zealand have for the major part been restricted to land considered marginal for agricultural and pastoral pursuits. On these marginal lands of relatively low fertility and difficult terrain, forestry can compete economically with agriculture. Radiata pine (Pinus radiata D. Don), the most important of the exotic softwoods, occupies some 600,000 acres in New Zealand, but, despite its versatility and adaptability, has in some instances been established on sites which are outside the limits of its tolerance. Such is the case at the Riverhead State Forest in the Auckland conservancy. In many sectors of this forest, radiata pine, planted during the period 1926-33 on podzolized gumland clays, manifested symptoms of ill-health and unthriftiness within a short time of establishment. These symptoms gave rise to concern and stimulated a programme of research into the possible causal factors. The fertilizer trial work conducted at Riverhead up till 1958 has been reviewed by Weston (1956, 1958). Conway (1962) discussed aerial application of phosphatic fertilizers at Riverhead, while Will (1965) reported the more recent nutritional work. This nutritional work, which has included tissue analyses and the study of growth responses to phosphatic and zinc fertilizer treatments, has shown quite conclusively that unthrifty trees in the trial areas manifest a considerable response to phosphate, but not to zinc. The degree of response to the application of superphosphate has been shown to be dependent upon the prior condition of the stand and the rate of application. Topdressing at a rate of 5cwt/acre of superphosphate as a standard practice has been tentatively adopted following these trials. Will (1965) has shown that foliar analysis can be a most useful aid in assessing the need for fertilizer and in predicting the likely response to fertilizer treatment.Item The effects of nitrate nitrogen and phosphate on the nodulation and nitrogen fixation of white cliver (Trifolium repens L.): a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science at Massey University(Massey University, 1974) Fillery, Ian R. PIt is a well established fact that the presence of nitrate ions can depress nodule development on legume roots, but recent studies in Queensland (Gates, 1970) have shown that this sensitivity can be ameliorated if phosphate levels are maintained at a high rate. Gates studies involved tropical legumes and their appropriate rhizebial symbionts, and this study was conducted to ascertain whether a similar situation obtains with a temperate species like Trifolium repens (White Clover). Quantitiative information on the effect of nitrate nitrogen and phosphate on nitrogen fixing activity in white clover was also lacking, and an attempt was made to rectify this deficiency by examining the changes in rate of ethylene production per plant or mg nodule (dry weight) with the application of nitrate nitrogen and higher rates of phosphate.Item Purification and characterisation of cell wall acid phosphatases of roots of white clover (Trifolium repens L.) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Plant Biology at Massey University, Palmerston North, New Zealand(Massey University, 1999) Zhang, Celia; Zhang, CeliaPlants of white clover (Trifolium repens L., cultivar Huia, genotype PgH2) were either grown in half-strength Hoaglands solution (P-containing media) or subjected to phosphate starvation by omitting the sole source phosphate (KH2PO4) from Hoaglands solution media for a period of five weeks. The phosphate content of the first fully expanded leaf was determined in plants from both treatments. After 2 weeks, the P content in leaves from plants grown in P-deprived media was significantly lower (p < 0.001) than the P-supplied plants, and continued to decrease over the 5-week time course. Ionically bound acid phosphatases were extracted with 1 M NaCl from the cell walls of roots. In roots of plants maintained in P-deprived media, acid phosphatase activity increased over the 5-week time course, while the activity in roots of plants grown in P-containing media did not change. After four weeks in P-deprived media, the cell wall ionically-bound acid phosphatase fraction was subjected to hydrophobic column chromatography and two distinct acid phosphatases (designated Apase I and Apase II) identified. There is a temporal difference in induction of Apase I and Apase II. After one week of P-deprivation, the activity of Apase II reached its maximum and did not increase further in following weeks. The activity of Apase I was only half that of Apase II after one week of P-deprivation, but increased continually to be significantly higher than the activity of Apase II by the end of week 4. Apase I and II were further purified using gel filtration column chromatography, and each enzyme subsequently separated further into two isoforms by ion-exchange chromatography. Both isoforms of Apase I (Ia and Ib) exist as active monomers of 52 kD as determined by SDS-PAGE and by gel filtration. For Apase II, both isoforms (IIa and IIb) also exist as active monomers of 112 kD as determined by SDS-PAGE and 92 kD by gel filtration. Both Ia and Ib are glycosylated as determined by recognition by a Galanthus nivalis (GNA) lectin (which recognises terminal mannose or oligomannose N-linked glycan chains) or by a monoclonal antibody YZ1/2.23 (which recognises xylose/fucose-containing complex-type glycan chains). Apase Ia was recognised by both sugar probes, while Apase Ib was recognised by YZ1/2.23 only. Apase IIa was not recognized by either of sugar probes, while Apase IIb is a glycoprotein as determined by recognition by YZ1/2.23. Using ρNPP as substrate, the pH optima for Apase Ia, Ib, IIa and IIb are 5.8, 6.2, 5.8 and 6.8, respectively. Isoelectric focusing determined that Apase Ia split into two bands with pI values of 7.0 and 7.3, Apase Ib showed a major band with a pI of 6.7, Apase IIa showed a single band with a pI of 4.4 and Apase IIb split into two closely located bands with pI values of 5.2 and 5.3. The activity of all four isoforms was severely inhibited by Cu2+, Zn2+ and molybdate. Fe3+ is also an inhibitor but not as potent as the other three metal ions. Co2+ and Al3+ displayed greater inhibition of Apase I when compared with Apase II. Tartrate and EDTA had no effect on the activity of all four isoforms, but inorganic phosphate is a strong inhibitor of all the four isoforms. Each of the four isoforms showed a broad range of substrate specificity, with ATP and PPi the preferred substrates, and PEP and 3-PGA the least preferred substrates. All four isoforms showed no hydrolysis activity toward phytic acid. A short sequence containing 5 amino acid residues was obtained from Apase Ib, but no significant sequence identity with any existing protein sequence was found.Item The role of ethylene and auxin in responses of roots to phosphate supply in white clover (Trifolium repens L.) : a thesis presentation in partial fulfilment of the requirements for the degree of Master of Science in Plant Molecular Biology at Massey University, Palmerston North, New Zealand(Massey University, 2009) Dinh, Phuong Thi YenPhosphate (P) supply is one of the major determining factors to plant productivity, since the element affects the growth and the development of plants. In response to Pdeficiency treatment, plants display alterations in root system architecture caused by changes in primary root (PR) and lateral root (LR) length and LR density. In this thesis, the root growth of the agronomically important legume, white clover (Trifolium repens L.) was found to be slightly stimulated in terms of PR length, LR number and total LR length when plants were grown in a P-deficient media (0.01 mM orthophosphate; Pi) when compared with plants grown in a P-sufficient media (1.00 mM Pi) when using a hydroponic growth system. When plants are grown in a P-sufficient media, treatment with 100 nM exogenous 1- aminocyclopropane-1-carboxylic acid (ACC) and exogenous auxin (5 nM 1- naphthylacetic acid, NAA) resulted in significant increases in white clover PR length, LR number and LR length. However, when ethylene action or auxin transport were inhibited using 300 ppm 1-methylcyclopropene (1-MCP) and 100 nM 1-Nnaphthylphthalamic acid (NPA), respectively, root growth was significantly reduced which suggests roles for ethylene and auxin in mediating white clover root growth. To examine the effects of these hormones on plants grown in P-deficient media, 100 nM ACC treatment significantly enhanced the stimulatory effects of growth on Pdeficient media only, while exposure of plants to P-deficiency alone was sufficient to significantly neutralise the inhibitory effects of 1-MCP on root growth. Hence, exposure to P-deficiency is proposed to increase either ethylene biosynthesis or ethylene sensitivity in white clover roots. In contrast, for plants grown in P-deficient media, treatment with 5 nM NAA significantly abolished the stimulation of white clover root growth observed with P-deficiency so it is proposed that exposure to Pdeficiency increases either auxin biosynthesis or auxin sensitivity, but the 5nM NAA concentration used was too high to stimulate root growth. Using DR5p::GUS transgenic white clover, auxin activity was found in the root tips and root primordia. Using these plants, it is suggested that P-deficient treatment and ACC treatment influenced white clover root growth through an increase in auxin sensitivity. Overall, ethylene and auxin are found to be essential in mediating white clover root growth in P-sufficiency, and also in mediating root responses to P-deficiency through changes in terms of the biosynthesis and the sensitivity of these two hormones.