title: Production and characterization of titanium based alloys with potential for antifouling and biofouling

authors: Alshammari, Yousef Namlan

subjects: Titanium

abstract: Biofouling is the settlement and accumulation of microorganisms on the surface of a material submerged in sea water, and most of the time is an unwanted phenomenon and constitutes a financial burden. Titanium is a lightweight high strength metal characterised by good corrosion resistance, better than stainless steel, and would be the ideal material to be used in marine applications. However, biofouling would still happen in structures made out of titanium.
The aim of this study is to gain understanding of the biofouling process to be able to design Ti-based materials with the potential to prevent, or conversely enhance, biofouling, as both scenarios could have relevant industrial applications. In particular, it was planned to manufacture the Ti-based materials via powder metallurgy to take advantage of the intrinsic benefits of these techniques which include the freedom of designing new alloys, without the limits imposed by binary phase diagrams.
From literature, it was found that Cu and Mn could have respectively, the ability to reduce or promote biofouling. Therefore, various binary Ti-xCu and Ti-yMn compositions, where x = 0.5%, 2.5%, 5%, and y = 1%, 5%, 10%, were targeted and successfully manufactured via the conventional powder metallurgy route of cold uniaxial pressing plus vacuum sintering, obtaining fully homogeneous materials. 
It is well known that residual porosity is still present in sintered Ti-based materials, and for that the binary Ti-xCu and Ti-yMn alloys were also a thermomechanical process via forging. This hot deformation process should reduce the amount of residual porosity, but it can also be used to tailor the microstructure, and thus the mechanical behaviour, which is paramount for many industrial applications. Along this line, it was decided to investigate the effect of the forging temperature (i.e. of the starting microfeatures) and thus forging from the β and within the α+β region was considered.
From the characterisation performed, the Ti-5Cu and Ti-5Mn alloys were chosen as the most promising alloys for the investigation of the antifouling and biofouling capability of the binary Ti-xCu and Ti-yMn alloys developed

text: Production and characterization of titanium based alloys with potential for antifouling and biofouling Biofouling is the settlement and accumulation of microorganisms on the surface of a material submerged in sea water, and most of the time is an unwanted phenomenon and constitutes a financial burden. Titanium is a lightweight high strength metal characterised by good corrosion resistance, better than stainless steel, and would be the ideal material to be used in marine applications. However, biofouling would still happen in structures made out of titanium.
The aim of this study is to gain understanding of the biofouling process to be able to design Ti-based materials with the potential to prevent, or conversely enhance, biofouling, as both scenarios could have relevant industrial applications. In particular, it was planned to manufacture the Ti-based materials via powder metallurgy to take advantage of the intrinsic benefits of these techniques which include the freedom of designing new alloys, without the limits imposed by binary phase diagrams.
From literature, it was found that Cu and Mn could have respectively, the ability to reduce or promote biofouling. Therefore, various binary Ti-xCu and Ti-yMn compositions, where x = 0.5%, 2.5%, 5%, and y = 1%, 5%, 10%, were targeted and successfully manufactured via the conventional powder metallurgy route of cold uniaxial pressing plus vacuum sintering, obtaining fully homogeneous materials. 
It is well known that residual porosity is still present in sintered Ti-based materials, and for that the binary Ti-xCu and Ti-yMn alloys were also a thermomechanical process via forging. This hot deformation process should reduce the amount of residual porosity, but it can also be used to tailor the microstructure, and thus the mechanical behaviour, which is paramount for many industrial applications. Along this line, it was decided to investigate the effect of the forging temperature (i.e. of the starting microfeatures) and thus forging from the β and within the α+β region was considered.
From the characterisation performed, the Ti-5Cu and Ti-5Mn alloys were chosen as the most promising alloys for the investigation of the antifouling and biofouling capability of the binary Ti-xCu and Ti-yMn alloys developed

year: 2017

title: The evolution of China’s nuclear weapons program and doctrine and its implications for international security

authors: Abbasi, Khusrow Akkas

subjects: International Relations

abstract: As China’s power in the international system increases, its strategic policies are changing. This includes its nuclear weapons program and nuclear deterrent policy, viewed as a critical guarantor of Beijing’s security and a tool that supports its growing regional and global interests. China’s evolving nuclear program and doctrine have multidimensional implications. This study critically examines the drivers of China’s ongoing nuclear weapons policy and force modernization by employing neoclassical realism. In doing so, it considers the implications of China’s nuclear program for international and regional security, and for strategic stability by exploring relevant case studies and dyads (China- US, China-Japan, China-South Korea, China-India, and China-Taiwan) and speculates on the future trajectory of China’s nuclear weapons modernization. In this context, China’s contemporary nuclear weapons force modernization is an ongoing process that started in late 2015 under President Xi Jinping’s rule.
The hypothesis of this thesis extends from this line of thinking, holding that the emerging nuclear program of China is increasing regional and international strategic insecurity. This involves China, the US and other regional powers, manifested in a “security dilemma”.1 An empirical and analytical approach is used to evaluate the hypothesis and critically deconstruct prevailing discourses. The methodology employs deductive reasoning that uses existing theory as a foundation for formulating and testing the hypothesis.
The findings show that China’s nuclear weapons policy and ongoing force modernization drivers are primarily structural. However, internal factors within China, such as its leadership and economic development, and bureaucratic competition between different services of the PLA also play a significant role in shaping China’s emerging full-spectrum deterrence posture calibrated towards limited nuclear war fighting. This breeds a spiral of insecurity vis-a-vis the US, Japan, South Korea, Taiwan, and India, is leading to greater strategic and crisis instability and an intensified security dilemma.

text: The evolution of China’s nuclear weapons program and doctrine and its implications for international security As China’s power in the international system increases, its strategic policies are changing. This includes its nuclear weapons program and nuclear deterrent policy, viewed as a critical guarantor of Beijing’s security and a tool that supports its growing regional and global interests. China’s evolving nuclear program and doctrine have multidimensional implications. This study critically examines the drivers of China’s ongoing nuclear weapons policy and force modernization by employing neoclassical realism. In doing so, it considers the implications of China’s nuclear program for international and regional security, and for strategic stability by exploring relevant case studies and dyads (China- US, China-Japan, China-South Korea, China-India, and China-Taiwan) and speculates on the future trajectory of China’s nuclear weapons modernization. In this context, China’s contemporary nuclear weapons force modernization is an ongoing process that started in late 2015 under President Xi Jinping’s rule.
The hypothesis of this thesis extends from this line of thinking, holding that the emerging nuclear program of China is increasing regional and international strategic insecurity. This involves China, the US and other regional powers, manifested in a “security dilemma”.1 An empirical and analytical approach is used to evaluate the hypothesis and critically deconstruct prevailing discourses. The methodology employs deductive reasoning that uses existing theory as a foundation for formulating and testing the hypothesis.
The findings show that China’s nuclear weapons policy and ongoing force modernization drivers are primarily structural. However, internal factors within China, such as its leadership and economic development, and bureaucratic competition between different services of the PLA also play a significant role in shaping China’s emerging full-spectrum deterrence posture calibrated towards limited nuclear war fighting. This breeds a spiral of insecurity vis-a-vis the US, Japan, South Korea, Taiwan, and India, is leading to greater strategic and crisis instability and an intensified security dilemma.

year: 2022

title: Adolescent Māori mothers experiences with social support during pregnancy, birth and motherhood and their participation in education

authors: Rawiri, Casey

subjects: social support

abstract: The purpose of this research was to investigate the role of social support in helping
adolescent Māori mothers cope with pregnancy, birth and motherhood, with a
particular emphasis on its role in enabling them to continue at school. The aim of this
research is to understand and make sense of these experiences and to perhaps identify
gaps within an individual's social network. The analysis and methodology of the
research was underpinned by a community psychology framework.
Nine interviews were conducted with young Māori women who had become pregnant
and continued with their pregnancy, all before the age of 20. The in depth interviews
included questions focusing on the young women learning of pregnancy, the
pregnancy, birth, caring for their child and their experiences with education and future
plans.
Negative experiences were usually those which involved unsupportive people.
Positive interactions were those where support, of all types, was offered and useful to
my participants and their children. Education was highlighted as the most effective
way of providing a better life for adolescent mothers and their children.
The research highlights the importance of social support and the continuation of
education. Combining the efforts of positive social networks and social support
services can improve the lives of adolescent Māori mothers and their children.

text: Adolescent Māori mothers experiences with social support during pregnancy, birth and motherhood and their participation in education The purpose of this research was to investigate the role of social support in helping
adolescent Māori mothers cope with pregnancy, birth and motherhood, with a
particular emphasis on its role in enabling them to continue at school. The aim of this
research is to understand and make sense of these experiences and to perhaps identify
gaps within an individual's social network. The analysis and methodology of the
research was underpinned by a community psychology framework.
Nine interviews were conducted with young Māori women who had become pregnant
and continued with their pregnancy, all before the age of 20. The in depth interviews
included questions focusing on the young women learning of pregnancy, the
pregnancy, birth, caring for their child and their experiences with education and future
plans.
Negative experiences were usually those which involved unsupportive people.
Positive interactions were those where support, of all types, was offered and useful to
my participants and their children. Education was highlighted as the most effective
way of providing a better life for adolescent mothers and their children.
The research highlights the importance of social support and the continuation of
education. Combining the efforts of positive social networks and social support
services can improve the lives of adolescent Māori mothers and their children.

year: 2007