title: Moisture sorption and plasticization of bloodmeal-based thermoplastics

authors: Verbeek, Casparus Johan R.

subjects: tri-ethylene glycol

abstract: Sorption characteristics, thermo-mechanical and mechanical properties of bloodmeal-based thermoplastics have been investigated between water activities (aw) of 0.2 and 0.8, using water and tri-ethylene glycol (TEG) as plasticizers. Three different mass ratios of TEG to water were used, 1:1, 1:2 and 5:6 with a total plasticizer content of 60 parts per hundred parts bloodmeal. It was found that the equilibrium moisture content and mechanical properties were highly dependent on relative humidity suggesting that material properties may vary during use. The BET and Flory–Huggins equations gave the best fit for desorption and adsorption, respectively, but a significant difference was observed between adsorption and desorption behaviour below a water activity of 0.6, which was thought to be due to changes in intermolecular interactions. The monolayer adsorption capacity (0.05 g/g) was unaffected by the TEG content, using the BET sorption isotherm. The water activity required to form a monolayer (awl) was also independent of the amount of TEG, but was different for adsorption and desorption (about 0.5 and 0.2, respectively). Increasing TEG did not have a strong influence on the equilibrium moisture content, especially at low water activity. Dynamic mechanical analysis revealed that the glass transition temperature decreased almost linearly with increasing water activity, ranging between 3 and 85 ℃, however, above a water activity of 0.6 a second transition was observed, most likely due to phase separation. Depending of TEG content, tensile strength increased from about 10 to 15 MPa at a water activity of 0.4, where after a drastic decrease was observed. A similar trend was observed for elongation at break. At low water activity (below 0.4) elongation was less than 3%, increasing between 30 and 50% at higher water activities. It was concluded that 10–15 wt% represented a critical point above which mechanical properties becomes very sensitive to the relative humidity of the environment.

text: Moisture sorption and plasticization of bloodmeal-based thermoplastics Sorption characteristics, thermo-mechanical and mechanical properties of bloodmeal-based thermoplastics have been investigated between water activities (aw) of 0.2 and 0.8, using water and tri-ethylene glycol (TEG) as plasticizers. Three different mass ratios of TEG to water were used, 1:1, 1:2 and 5:6 with a total plasticizer content of 60 parts per hundred parts bloodmeal. It was found that the equilibrium moisture content and mechanical properties were highly dependent on relative humidity suggesting that material properties may vary during use. The BET and Flory–Huggins equations gave the best fit for desorption and adsorption, respectively, but a significant difference was observed between adsorption and desorption behaviour below a water activity of 0.6, which was thought to be due to changes in intermolecular interactions. The monolayer adsorption capacity (0.05 g/g) was unaffected by the TEG content, using the BET sorption isotherm. The water activity required to form a monolayer (awl) was also independent of the amount of TEG, but was different for adsorption and desorption (about 0.5 and 0.2, respectively). Increasing TEG did not have a strong influence on the equilibrium moisture content, especially at low water activity. Dynamic mechanical analysis revealed that the glass transition temperature decreased almost linearly with increasing water activity, ranging between 3 and 85 ℃, however, above a water activity of 0.6 a second transition was observed, most likely due to phase separation. Depending of TEG content, tensile strength increased from about 10 to 15 MPa at a water activity of 0.4, where after a drastic decrease was observed. A similar trend was observed for elongation at break. At low water activity (below 0.4) elongation was less than 3%, increasing between 30 and 50% at higher water activities. It was concluded that 10–15 wt% represented a critical point above which mechanical properties becomes very sensitive to the relative humidity of the environment.

year: 2011

title: Renewable integration options for remote New Zealand community

authors: Kumar Jayasankar, Naveen

abstract: About 35% of New Zealand’s population lives in rural and remote areas like Whitianga and its nearby settlements. These areas are facing growing electricity demand due to rising population, business activity, and the shift to cleaner transport such as EV and FCEV. This trend is expected to put additional pressure on existing electricity infrastructure and networks, many of which were not built to handle such loads. A potential solution is to utilize local renewable energy sources, such as solar, wind, and green hydrogen, to reduce reliance on the national grid and delay costly infrastructure upgrades.
The first part of the thesis investigates the dynamic behaviour of a PEM electrolyser as a likely component in future integrated renewable energy systems. A Python-based simulation compares the hydrogen production output of dynamic and static models of a PEM under variable solar PV inputs. For the PEM capacity selected, there was a modest difference in cumulative hydrogen output from the dynamic model compared to the static model using one-minute input data over a whole day. Potentially, the dynamic model provides a more accurate way to size electrolyser and associated units like compressor and hydrogen storage vessels with the fluctuating electrical input conditions.
The second part evaluates the use of rooftop solar PV, wind, and hybrid solar-wind systems integrated with green hydrogen into a single residential house to achieve various levels of self-sufficiency over a full year. The study models energy balance, hydrogen storage, and levelized cost of energy (LCOE) for a range of system sizes, showing that 100% self-sufficiency is achievable in all three options, but only at extremely high LCOE levels between 0.52 and 0.78 NZD/kWh. Among the options, the hybrid system of solar and wind performs best, achieving complete self-sufficiency (100%) at the lowest cost of 0.52 NZD/kWh while balancing energy generation and storage needs with demand.
The third part presents a case study of the Whitianga township and region, exploring the integration of solar PV, Vehicle-to-grid (V2G), and green hydrogen to meet future energy demand. A techno-economic assessment examines residential, commercial, and transport energy needs from 2024 to 2050 and evaluates how a 32 MWp solar PV energy system can supply local demand while reducing reliance on the national grid and the need for local transformer upgrades. Two approaches were investigated: a centralised solar farm approach plus local hydrogen production & EV charging demand, and a decentralised residential rooftop solar approach supported by V2G electricity storage. The results indicate that the centralised approach has the lowest LCOE of 0.107 NZD/kWh, while the local grid upgrade remains unavoidable, even with higher solar penetration to the local grid. But in terms of payback period, the decentralised approach has a significant advantage, even with the higher investment cost, especially when V2G is incorporated into the energy management system. The initial investment amount can be recovered in 12.01 years with 20kWh of V2G battery storage.

text: Renewable integration options for remote New Zealand community About 35% of New Zealand’s population lives in rural and remote areas like Whitianga and its nearby settlements. These areas are facing growing electricity demand due to rising population, business activity, and the shift to cleaner transport such as EV and FCEV. This trend is expected to put additional pressure on existing electricity infrastructure and networks, many of which were not built to handle such loads. A potential solution is to utilize local renewable energy sources, such as solar, wind, and green hydrogen, to reduce reliance on the national grid and delay costly infrastructure upgrades.
The first part of the thesis investigates the dynamic behaviour of a PEM electrolyser as a likely component in future integrated renewable energy systems. A Python-based simulation compares the hydrogen production output of dynamic and static models of a PEM under variable solar PV inputs. For the PEM capacity selected, there was a modest difference in cumulative hydrogen output from the dynamic model compared to the static model using one-minute input data over a whole day. Potentially, the dynamic model provides a more accurate way to size electrolyser and associated units like compressor and hydrogen storage vessels with the fluctuating electrical input conditions.
The second part evaluates the use of rooftop solar PV, wind, and hybrid solar-wind systems integrated with green hydrogen into a single residential house to achieve various levels of self-sufficiency over a full year. The study models energy balance, hydrogen storage, and levelized cost of energy (LCOE) for a range of system sizes, showing that 100% self-sufficiency is achievable in all three options, but only at extremely high LCOE levels between 0.52 and 0.78 NZD/kWh. Among the options, the hybrid system of solar and wind performs best, achieving complete self-sufficiency (100%) at the lowest cost of 0.52 NZD/kWh while balancing energy generation and storage needs with demand.
The third part presents a case study of the Whitianga township and region, exploring the integration of solar PV, Vehicle-to-grid (V2G), and green hydrogen to meet future energy demand. A techno-economic assessment examines residential, commercial, and transport energy needs from 2024 to 2050 and evaluates how a 32 MWp solar PV energy system can supply local demand while reducing reliance on the national grid and the need for local transformer upgrades. Two approaches were investigated: a centralised solar farm approach plus local hydrogen production & EV charging demand, and a decentralised residential rooftop solar approach supported by V2G electricity storage. The results indicate that the centralised approach has the lowest LCOE of 0.107 NZD/kWh, while the local grid upgrade remains unavoidable, even with higher solar penetration to the local grid. But in terms of payback period, the decentralised approach has a significant advantage, even with the higher investment cost, especially when V2G is incorporated into the energy management system. The initial investment amount can be recovered in 12.01 years with 20kWh of V2G battery storage.

year: 2025-07-11

title: Balancing openness with Indigenous data sovereignty: An opportunity to leave no one behind in the journey to sequence all of life

authors: Cartney, Ann M. Mc

abstract: The field of genomics has benefited greatly from its "openness" approach to data sharing. However, with the increasing volume of sequence information being created and stored and the growing number of international genomics efforts, the equity of openness is under question. The United Nations Convention of Biodiversity aims to develop and adopt a standard policy on access and benefit-sharing for sequence information across signatory parties. This standardization will have profound implications on genomics research, requiring a new definition of open data sharing. The redefinition of openness is not unwarranted, as its limitations have unintentionally introduced barriers of engagement to some, including Indigenous Peoples. This commentary provides an insight into the key challenges of openness faced by the researchers who aspire to protect and conserve global biodiversity, including Indigenous flora and fauna, and presents immediate, practical solutions that, if implemented, will equip the genomics community with both the diversity and inclusivity required to respectfully protect global biodiversity.

text: Balancing openness with Indigenous data sovereignty: An opportunity to leave no one behind in the journey to sequence all of life The field of genomics has benefited greatly from its "openness" approach to data sharing. However, with the increasing volume of sequence information being created and stored and the growing number of international genomics efforts, the equity of openness is under question. The United Nations Convention of Biodiversity aims to develop and adopt a standard policy on access and benefit-sharing for sequence information across signatory parties. This standardization will have profound implications on genomics research, requiring a new definition of open data sharing. The redefinition of openness is not unwarranted, as its limitations have unintentionally introduced barriers of engagement to some, including Indigenous Peoples. This commentary provides an insight into the key challenges of openness faced by the researchers who aspire to protect and conserve global biodiversity, including Indigenous flora and fauna, and presents immediate, practical solutions that, if implemented, will equip the genomics community with both the diversity and inclusivity required to respectfully protect global biodiversity.

year: 2022