title: Time dependent properties of thermoplastic protein produced from bloodmeal with sodium sulphite as an anti-crosslinking agent

authors: Bier, James Michael

abstract: The aim of this research was to investigate how the time dependent mechanical behaviour of bloodmeal-based thermoplastic was affected by varying sodium sulphite content at two injection moulding temperatures (120°C at exit or 140°C at exit). Thermoplastic protein was prepared by extrusion with 2, 3 or 4g sodium sulphite (SS), 3g sodium dodecyl sulphate, 10 g urea, 20 g triethylene glycol and 40 g water per 100 g bloodmeal, then injection moulded into test specimens. Pull to break, creep and stress relaxation tests were performed on conditioned samples and glass transition temperature (Tg) was determined by dynamic mechanical analysis.
Ultimate tensile strength was 7.9, 7.6 and 5.6 MPa for samples moulded at 120°C and 7.6, 6.3 and 5.7 MPa when moulded at 140°C with 2, 3 and 4 g SS respectively. Experimental creep data was modelled with a 4 element model, consisting of a spring and dashpot in parallel, in series with an additional spring and dashpot. Plotting creep compliance versus time showed increasing chain mobility as SS content increased. Relaxation was modelled with the Struik equation for short-time experiments. Relaxation times were 530, 360 and 250 s with 2, 3 and 4 g SS respectively when moulded at the lower temperature. At 140°C, relaxation times were 440, 430 and 190 s for these SS contents. Tg was in the range 57-65°C (1 Hz peak in tanδ) for all samples, but was lowest for samples with 4 g SS.
These results show that both increased sodium sulphite and the higher moulding temperature increased chain mobility in the processed plastic.

text: Time dependent properties of thermoplastic protein produced from bloodmeal with sodium sulphite as an anti-crosslinking agent The aim of this research was to investigate how the time dependent mechanical behaviour of bloodmeal-based thermoplastic was affected by varying sodium sulphite content at two injection moulding temperatures (120°C at exit or 140°C at exit). Thermoplastic protein was prepared by extrusion with 2, 3 or 4g sodium sulphite (SS), 3g sodium dodecyl sulphate, 10 g urea, 20 g triethylene glycol and 40 g water per 100 g bloodmeal, then injection moulded into test specimens. Pull to break, creep and stress relaxation tests were performed on conditioned samples and glass transition temperature (Tg) was determined by dynamic mechanical analysis.
Ultimate tensile strength was 7.9, 7.6 and 5.6 MPa for samples moulded at 120°C and 7.6, 6.3 and 5.7 MPa when moulded at 140°C with 2, 3 and 4 g SS respectively. Experimental creep data was modelled with a 4 element model, consisting of a spring and dashpot in parallel, in series with an additional spring and dashpot. Plotting creep compliance versus time showed increasing chain mobility as SS content increased. Relaxation was modelled with the Struik equation for short-time experiments. Relaxation times were 530, 360 and 250 s with 2, 3 and 4 g SS respectively when moulded at the lower temperature. At 140°C, relaxation times were 440, 430 and 190 s for these SS contents. Tg was in the range 57-65°C (1 Hz peak in tanδ) for all samples, but was lowest for samples with 4 g SS.
These results show that both increased sodium sulphite and the higher moulding temperature increased chain mobility in the processed plastic.

year: 2012

title: Reduced magnetohydrodynamics and parallel spectral transfer

authors: Oughton, Sean

subjects: mathematics

abstract: The self-consistency of the reduced magnetohydrodynamics (RMHD) model is explored by examining whether (parallel) spectral transfer might invalidate the assumptions employed in deriving it. Using direct numerical simulations we find that transfer of energy to structures with high parallel wavenumber is in fact limited by ongoing perpendicular transfer. Thus, the dynamics associated with RMHD models remains consistent with the underlying assumptions of RMHD. In particular, in well-resolved simulations it is neither necessary nor correct to introduce additional dissipation terms that (artificially) damp spectral transfer parallel to the mean magnetic field B0.

text: Reduced magnetohydrodynamics and parallel spectral transfer The self-consistency of the reduced magnetohydrodynamics (RMHD) model is explored by examining whether (parallel) spectral transfer might invalidate the assumptions employed in deriving it. Using direct numerical simulations we find that transfer of energy to structures with high parallel wavenumber is in fact limited by ongoing perpendicular transfer. Thus, the dynamics associated with RMHD models remains consistent with the underlying assumptions of RMHD. In particular, in well-resolved simulations it is neither necessary nor correct to introduce additional dissipation terms that (artificially) damp spectral transfer parallel to the mean magnetic field B0.

year: 2004-04-16

title: He titiro ki ētahi o ngā rerekētanga me ngā ritenga o te karakia tūturu Māori me ngā karakia karaitiana Māori

authors: Murphy, Ēnoka

subjects: Karakia

abstract: Puta noa i Aotearoa he maha tonu ngā wāhi me ngā wā e rāngona ai e te tangata tēnei mea te karakia. O ēnei wā ko ngā karakia e rangona ai he karakia Māori tonu engari kua kaha kē ake te hari i te karakia karaitiana me ōna whakatakotoranga. Ka mutu, tērā rā ētahi rerekētanga me ētahi ritenga o te karakia Māori tūturu nei me ērā o te karakia karaitiana. Nā, nō roto ake i ngā tau toru tekau nei, kua nui te whawhai a te Māori puta noa ki te hahū ake, ki te whakahoki mai, ki te whakaora mai anō i tōna reo, i ōna tikanga, i tōna titiro tonu ki tōna ao kia pakari ai, kia noho mārō hītarari mai anō ai mō ngā uri whakatupuranga kei te heke. Nā reira, e whai take ana kia whēiroiro ai ētahi o ngä rerekētanga me ngā ritenga tonu o ngā momo karakia e rua nei.

text: He titiro ki ētahi o ngā rerekētanga me ngā ritenga o te karakia tūturu Māori me ngā karakia karaitiana Māori Puta noa i Aotearoa he maha tonu ngā wāhi me ngā wā e rāngona ai e te tangata tēnei mea te karakia. O ēnei wā ko ngā karakia e rangona ai he karakia Māori tonu engari kua kaha kē ake te hari i te karakia karaitiana me ōna whakatakotoranga. Ka mutu, tērā rā ētahi rerekētanga me ētahi ritenga o te karakia Māori tūturu nei me ērā o te karakia karaitiana. Nā, nō roto ake i ngā tau toru tekau nei, kua nui te whawhai a te Māori puta noa ki te hahū ake, ki te whakahoki mai, ki te whakaora mai anō i tōna reo, i ōna tikanga, i tōna titiro tonu ki tōna ao kia pakari ai, kia noho mārō hītarari mai anō ai mō ngā uri whakatupuranga kei te heke. Nā reira, e whai take ana kia whēiroiro ai ētahi o ngä rerekētanga me ngā ritenga tonu o ngā momo karakia e rua nei.

year: 2011