4,965 research outputs found

    Investigating scientific literacy: Scientist’s habits of mind as evidenced by their rationale of science and religious beliefs

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    Science and technology have been incredibly success¬ful in purely technical terms. For instance, international air travel, space flight, and curing of hitherto untreatable medical illnesses all are now routine events. One feature of the incredible (and seemingly ever increasing) advance of science and technology is a sense of unease amongst the general population of science’s potential to change our lives, in sometimes unpredictable and alarming ways. Public understanding of science, or scientific literacy, is of increasing concern worldwide according to much recent literature

    Two phase aqueous extraction of whey proteins in a polyethylene glycol - arabinogalactan system

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    The whey protein separation potential of aqueous two-phase systems of arabinogalactan [AG] (Lonza FiberAidTM) and polyethylene glycol [PEG], buffered with 10 mmol/g phosphate or citrate buffer, was studied. 100 mmol/g potassium chloride [KCl] was added as required. Previously-published phase equilibrium results were verified and the absorbance of whey protein isolate [WPI] in an AG-PEG solution was measured. The effect of pH, KCl concentration, initial WPI concentrations and upper to lower phase mass ratios on whey partitioning was studied. The best separation system contained 17.20% (w/w) AG, 7.20% (w/w) PEG, 10 mmol citrate buffer (pH 5.4) and 100 mmol KCl per gram of total system. The upper to lower phase mass and volume ratios were 1:1 and 16:11 respectively. Approximately 12 mg (mainly α-lactalbumin) of the 20 mg WPI added partitioned into the AG-rich upper phase. This system has potential to reduce chromatographic requirements in large scale separation of protein mixtures

    Settling of bentonite in gelatine solutions

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    New Zealand has a sizeable meat by-products processing industry, associated with significant aqueous effluent called stickwater. Stickwater has a biological oxygen demand of 50-150 g O₂/l and has to be treated prior to disposal. Currently, stickwater is dried and added to meat and bone meal in some inedible meat rendering plants. In edible rendering plants, the gelatin can be removed and the remaining broth is concentrated as a flavor enhancer. Where no further unit operations are carried out on stickwater, the stickwater must be treated to reduce the BOD. A medium size meat rendering plant in NZ can produce up to 30,000 L of stickwater at 2-5% solids per day¹. In Hamilton, waste water treatment costs NZ0.90perkgsolidsorapproximatelyNZ0.90 per kg solids or approximately NZ1350 per day. In comparison, abattoir waste treatment costs NZ$ 0.23/kg in the US.

    Processing peracetic acid treated bloodmeal into bioplastic

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    Renewable and biodegradable bioplastics can be produced from biopolymers such as proteins. Animal blood is a by-product from meat processing and is rich in protein. It is dried into low value bloodmeal and is used as animal feed or fertiliser. Previous work has shown that bloodmeal can be converted into a thermoplastic using water, urea, sodium dodecyl sulphate (SDS), sodium sulphite and triethylene glycol (TEG). To increase its range of applications and acceptance from consumers, the colour and odour was removed from bloodmeal using peracetic acid (PAA). The aim of this study was to investigate the bioplastic processing of 3-5% (w/w) PAA treated bloodmeal. 3-5% PAA treated bloodmeal powder was compression moulded using different combinations of water, TEG, glycerol, SDS, sodium sulphite, urea, borax, salt and sodium silicate at concentrations up to 60 parts per hundred bloodmeal (pphBM). Partially consolidated extrudates and fully consolidated compression moulded sheets were obtained using a combination of water, TEG and SDS. 4% PAA treated bloodmeal produced the best compression moulded sheets and extrudates and was chosen for investigating the effects of water, TEG and SDS concentration on consolidation, specific mechanical energy input (SME) and product colour during extrusion. Analysis of variance (ANOVA) showed SDS was the most important factor influencing its ability to be extruded because it detangled protein chains and allowed them to form new stabilising interactions required for consolidation. The best extruded sample, which was 98% consolidated and 49% white, contained 40 pphBM water, 10 pphBM TEG and 6 pphBM SDS

    Continuum discretized BCS approach for weakly bound nuclei

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    The Bardeen-Cooper-Schrieffer (BCS) formalism is extended by including the single-particle continuum in order to analyse the evolution of pairing in an isotopic chain from stability up to the drip line. We propose a continuum discretized generalized BCS based on single-particle pseudostates (PS). These PS are generated from the diagonalization of the single-particle Hamiltonian within a Transformed Harmonic Oscillator (THO) basis. The consistency of the results versus the size of the basis is studied. The method is applied to neutron rich Oxygen and Carbon isotopes and compared with similar previous works and available experimental data. We make use of the flexibility of the proposed model in order to study the evolution of the occupation of the low-energy continuum when the system becomes weakly bound. We find a larger influence of the non-resonant continuum as long as the Fermi level approaches zero.Comment: 20 pages, 16 figures, to be submitte

    An aeronautical mobile satellite experiment

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    The various activities and findings of a NASA/FAA/COMSAT/INMARSAT collaborative aeronautical mobile satellite experiment are detailed. The primary objective of the experiment was to demonstrate and evaluate an advanced digital mobile satellite terminal developed at the Jet Propulsion Laboratory under the NASA Mobile Satellite Program. The experiment was a significant milestone for NASA/JPL, since it was the first test of the mobile terminal in a true mobile satellite environment. The results were also of interest to the general mobile satellite community because of the advanced nature of the technologies employed in the terminal

    Fish powder as a low-cost component in media for producing bacterial cellulose

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    Some bacteria can produce extracellular bacterial cellulose (BC). This polysaccharide is chemically identical to cellulose produced by plants but has no associated lignin and hemicelluloses. The unique mechanical properties, chemical stability and purity allow BC to be exploited for a range of biomedical applications. However, medium costs limit commercial BC production. The suitability of using fish powder as a low-cost media component for producing BC by submerged culture of Gluconacetobacter xylinus in shake flasks was investigated. Fish powder was made by drying and grinding Koi carp (Cyprinus carpio), a pest fish in New Zealand waterways. Fermentations were done at 30oC in a growth medium containing 50 g/L glucose, the required minerals, and either 5 g/L yeast extract or 15 g/L fish powder, The BC yield on both yeast extract and fish powder was 0.04 g/g glucose, demonstrating fish powder was a suitable low cost ingredient for supplying nitrogen and amino acids in the media

    Decolouring bloodmeal: Consumption and potential recycling of peracetic acid

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    A method of deodorizing and decolouring bloodmeal using an equilibrium mixture of peracetic acid, hydrogen peroxide, acetic acid and water has been developed to improve its marketability as a source of protein for bioplastics. The objective of this study was to determine what quantity of peracetic acid is required to give reasonable bleaching of the bloodmeal and determine whether there is potential for the wastewater to be recycled. This was carried out by measuring the quantity of chemical species in the initial equilibrium mixture and the resulting wastewater upon bleaching using volumetric analysis. Bleaching efficacy was determined after exposing 100 g bloodmeal to 1.1, 2.5, 3.6, 4.5 and 5.6 wt% peracetic acid solutions as either 300 g total solution or a constant molar equivalent of 2.2 mmol peracetic acid/g bloodmeal and using a chromameter to measure colour change. Addition of 300 g 5.6 wt% peracetic acid solution resulted in effective bleaching. This represented a ratio of 2.20 mmol peracetic acid/g bloodmeal of which 1.4 mmol peracetic acid/g bloodmeal was consumed (63%). If 300 g 300 g of <2.5 wt% solution is added such that there is still 2.2 mmol peracetic acid/g bloodmeal, bleaching is still insufficient. These results suggest that an excess of peracetic is required for bleaching to occur, and that its concentration is paramount to bleaching efficacy. Due to the excess of peracetic acid used in the bleaching process, there is potential for wastewater recycling to be carried out provided that the wastewater is not diluted

    Effect of oxidative treatment on the secondary structure of decoloured bloodmeal

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    Bloodmeal can be decoloured using peracetic acid resulting in a material with a pale-yellow colour which only needs sodium dodecyl sulphate, water and triethylene glycol to extrude into a semi-transparent bioplastic. Fourier-transform infrared (FTIR) spectroscopy using Synchrotron light was used to investigate the effect of peracetic acid treatment at various concentrations on the spatial distribution of secondary structures within particles of bloodmeal. Oxidation caused aggregation of helical structures into sheets and acetic acid suppressed sheet formation. Decolouring with peracetic acid led to particles with a higher degree of disorder at the outer edges and higher proportions of ordered structures at the core, consistent with the expected diffusion controlled heterogeneous phase decolouring reaction. The degradation of stabilizing intra- and intermolecular interactions and the presence of acetate ions results in increased chain mobility and greater amorphous content in the material, as evidenced by reduction in Tg and greater enthalpy of relaxation with increasing PAA concentration

    An 8-DPSK TCM modem for MSAT-X

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    This paper describes the real-time digital implementation of an 8-differentiated phase-shift keying (DPSK) trellis-coded modulation (TCM) modem for operation on an L-band, 5 kHz wide, land mobile satellite (LMS) channel. The modem architecture as well as some of the signal processing techniques employed in the modem to combat the LMS channel impairments are described, and the modem performance over the fading channel is presented
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