title: Isolation and crystallographic characterization of solvate- and anion-stabilized PCP pincer complexes of palladium(II)

authors: Neo, Kian Eang

subjects: pincer

abstract: Pincer PCP-Pd(II) complex [PdCl(PCP)] (1) (PCP = −CH(CH₂CH₂PPh₂)₂) reacts with AgNO₃ to give [Pd(NO₃)(PCP)] (2). Similar reaction with AgBF₄ gives the aqua complex [Pd(OH₂)(PCP)][BF₄] (3) and the dinuclear complex [{Pd(PCP)}₂(μ-Cl)][BF₄] (4) with singly bridging chloro ligand. All new complexes were characterized by NMR spectroscopy, ESI-MS and single-crystal X-ray diffraction. Complex 1 and the triflate complex [Pd(OTf)(PCP)] (5) are active towards Suzuki–Miyaura coupling between aryl bromides and phenyl boronic acid.

text: Isolation and crystallographic characterization of solvate- and anion-stabilized PCP pincer complexes of palladium(II) Pincer PCP-Pd(II) complex [PdCl(PCP)] (1) (PCP = −CH(CH₂CH₂PPh₂)₂) reacts with AgNO₃ to give [Pd(NO₃)(PCP)] (2). Similar reaction with AgBF₄ gives the aqua complex [Pd(OH₂)(PCP)][BF₄] (3) and the dinuclear complex [{Pd(PCP)}₂(μ-Cl)][BF₄] (4) with singly bridging chloro ligand. All new complexes were characterized by NMR spectroscopy, ESI-MS and single-crystal X-ray diffraction. Complex 1 and the triflate complex [Pd(OTf)(PCP)] (5) are active towards Suzuki–Miyaura coupling between aryl bromides and phenyl boronic acid.

year: 2008

title: The effect of biochar as a partial replacement of cement in cement mortar mixture and its mechanical properties

authors: Wazir, Paras

abstract: Carbon Dioxide (CO2) pollution is one of the leading causes of present day environmental issues. The construction industry, having a huge cement production contributes to these issues such as global warming and climate change. According to Mota-Panizio et al., (2023),  the third largest CO2 emission contributor is cement production. Several research has been done on agricultural waste solutions which includes the use of rice husk, sugarcane bagasse, and biochar as a partial replacement to cement mortar and concrete. This study will focus on the use and benefits of biochar as a partial replacement to cement, not only results in a decrease in usage of cement, lessening  CO2 but as this study will show, it will also help in improving the mechanical properties of cement mortar. The biochar used in this study is a Pinus Radiata Sawdust Biochar, a commercial biochar made in New Zealand. This study finds that 2-3% of biochar as a partial replacement to cement in cement mortar is the optimum percentage with a D50, 0.0172mm particle size and with an 818m2/kg specific area, in which the mechanical properties would prove to be better than that of a pure cement mixture. To determine the internal curing ability of biochar, it is observed in the 3rd batch , a mix with 2% of biochar water cured for 3 days has the same 28-day compressive strength as the control mix was cured for 7 days. It is also found in this experimental study 1-3% of biochar replacement with cement mortar gave increased compressive strength compared to plain cement mortar in all days of curing.  

While biochar can be produced from agricultural wastes, it can also be derived from forest waste. Not only does it help in eliminating CO2 emission, it also adds commercial value to forestry waste providing an opportunity to use rather than discard it. One consequence of climate change is an increase in the number of extreme weather events such as Cyclone Gabrielle in 2023. The effects of this were made worse in some parts of the country due to accumulated forestry waste which blocked waterways making the flooding worse and damaging essential infrastructure.

 The main questions this study asks are: How does Biochar influence the mechanical properties of cement mortar such as flexural strength, flowability, and compressive strength? How is the incorporation of Biochar to cement mortar significant in lessening the increase of CO2 emission? And In which ways can the use of Biochar help improve forest waste management most especially in New Zealand?  To answer these questions, conducted tests of flowability, compressive strength, flexural strength, TGA, and SEM Analysis that would determine which percentage best depicts the effect of biochar to cement mortar and analyze the mechanical properties of cement mortar when combined with Biochar.

text: The effect of biochar as a partial replacement of cement in cement mortar mixture and its mechanical properties Carbon Dioxide (CO2) pollution is one of the leading causes of present day environmental issues. The construction industry, having a huge cement production contributes to these issues such as global warming and climate change. According to Mota-Panizio et al., (2023),  the third largest CO2 emission contributor is cement production. Several research has been done on agricultural waste solutions which includes the use of rice husk, sugarcane bagasse, and biochar as a partial replacement to cement mortar and concrete. This study will focus on the use and benefits of biochar as a partial replacement to cement, not only results in a decrease in usage of cement, lessening  CO2 but as this study will show, it will also help in improving the mechanical properties of cement mortar. The biochar used in this study is a Pinus Radiata Sawdust Biochar, a commercial biochar made in New Zealand. This study finds that 2-3% of biochar as a partial replacement to cement in cement mortar is the optimum percentage with a D50, 0.0172mm particle size and with an 818m2/kg specific area, in which the mechanical properties would prove to be better than that of a pure cement mixture. To determine the internal curing ability of biochar, it is observed in the 3rd batch , a mix with 2% of biochar water cured for 3 days has the same 28-day compressive strength as the control mix was cured for 7 days. It is also found in this experimental study 1-3% of biochar replacement with cement mortar gave increased compressive strength compared to plain cement mortar in all days of curing.  

While biochar can be produced from agricultural wastes, it can also be derived from forest waste. Not only does it help in eliminating CO2 emission, it also adds commercial value to forestry waste providing an opportunity to use rather than discard it. One consequence of climate change is an increase in the number of extreme weather events such as Cyclone Gabrielle in 2023. The effects of this were made worse in some parts of the country due to accumulated forestry waste which blocked waterways making the flooding worse and damaging essential infrastructure.

 The main questions this study asks are: How does Biochar influence the mechanical properties of cement mortar such as flexural strength, flowability, and compressive strength? How is the incorporation of Biochar to cement mortar significant in lessening the increase of CO2 emission? And In which ways can the use of Biochar help improve forest waste management most especially in New Zealand?  To answer these questions, conducted tests of flowability, compressive strength, flexural strength, TGA, and SEM Analysis that would determine which percentage best depicts the effect of biochar to cement mortar and analyze the mechanical properties of cement mortar when combined with Biochar.

year: 2024

title: ‘Pakeha Bill’: William John McClear, a Pakeha who lived at Te Aroha

authors: Hart, Philip

abstract: Born in Ireland to a Scottish soldier named McAleer, McClear, as he would re-name himself, was uncertain of his age, his birthplace, and the spelling of his name – for, like his parents, he was illiterate. After his drunken father, who abandoned his wife and family, sold him to unknown Maori at an unknown date, he was educated in a Maori school and was unable to speak English until the early 1870s, when he was living with Ngati Rahiri at Omahu pa, at Te Aroha. When Pakeha visitors first met him in 1877, he was a popular resident there and known as Pakeha Bill (or Pakeha William).
Possiby involved in mining before the Te Aroha rush, he both invested in and mined in several claims there from 1880 onwards, and at the end of that decade was one of a small group of Waiorongomai miners who took up a claim at Thames. When not mining, he took whatever jobs were available, struggling financially, in part because of a fondness for drink. As, unlike other Pakeha Maori, there was no evidence of his forming a close relationship with any Maori women, he did not benefit from a Maori wife’s landholdings, and he died in poverty.

text: ‘Pakeha Bill’: William John McClear, a Pakeha who lived at Te Aroha Born in Ireland to a Scottish soldier named McAleer, McClear, as he would re-name himself, was uncertain of his age, his birthplace, and the spelling of his name – for, like his parents, he was illiterate. After his drunken father, who abandoned his wife and family, sold him to unknown Maori at an unknown date, he was educated in a Maori school and was unable to speak English until the early 1870s, when he was living with Ngati Rahiri at Omahu pa, at Te Aroha. When Pakeha visitors first met him in 1877, he was a popular resident there and known as Pakeha Bill (or Pakeha William).
Possiby involved in mining before the Te Aroha rush, he both invested in and mined in several claims there from 1880 onwards, and at the end of that decade was one of a small group of Waiorongomai miners who took up a claim at Thames. When not mining, he took whatever jobs were available, struggling financially, in part because of a fondness for drink. As, unlike other Pakeha Maori, there was no evidence of his forming a close relationship with any Maori women, he did not benefit from a Maori wife’s landholdings, and he died in poverty.

year: 2016