3D printing a transposed design in biopolymer materials using an articulated robot and pellet-based extrusion : a thesis presented in partial fulfilment of the requirements for a degree of Master of Engineering in Mechatronics at Massey University, Albany, New Zealand

The aim of this project was to develop a new method of 3D printing. This method is a mix between Fused Deposition Modelling and freeform printing, using a 6 degree-of-freedom articulated robot and a pellet-based extruder to mix and distribute the biopolymer, to create commercial quality thin-shelled parts with aesthetic aspects unique to the process and with a reduced amount of material wastage. There is the potential for many industries to benefit from this new technology. Initially this project is focused on applications for artists as thin-shelled designs rarely provide the physical properties required for functional parts. An artist has provided a design to test the printer. The hopper is designed to work with a range of different polymer pellets. It is based off a previous student’s design and mimics the operation of an injection moulder by pushing the pellets through a heating chamber with an auger. The robot controlling the movement of the platform is an ABB IRB120. This robot has six degrees-of-freedom that allows it to reach several positions that would otherwise be impossible with a Cartesian system. The IRB120 has a very high spatial accuracy and repeatability. The design’s original format is converted to a flattened 2D format and the lines are interpolated to produce a 2D set of points. The overlaps in the shapes are removed to reduce the number of times the nozzle traces over previous paths, which helps to keep the layer thicknesses the same. These shapes are filled in with points so the contours are not empty. The points are then projected onto a mathematical model of the platform to produce a 3D point cloud. Finally, these points are converted into data for the robot to read. The design data points stream to the robot, which interprets them on the fly. Many iterative changes and improvements were done to the hardware and software as the result of continuous testing of the process and analysis of the print. The pellet-based extruder is an elementary design with numerous variables that affect the resulting extrusion. After many design iterations and improvements to the extruder, the extruder can produce a continuous strand of material, with relatively constant flow. The software accurately converts a design from the given format into a path for the contours, and another path to fill the contours. These paths are projected onto a model of the moulded platform. Each point along the path is put through multiple affine transforms to generate a location and orientation for the end effector of the robot. The robot is moved by streaming each point to the robot one at a time. The extruder was controlled simultaneously to create a printed design. The printed design is geometrically correct. However, the width of the extrusion path needs to be improved to increase the accuracy of the design to the reference one. The current prints achieve the correct visual properties in the extrusion. However, they require a secondary process to improve the surface finish. This project has produced a new 3D printing process, mixing Fused Deposition Modelling and freeform printing. This process can be adapted to be used in a wide range of applications. It has also produced a low-cost, effective pellet-based extruder that can be used to test a range of different materials, and their effectiveness in being used for 3D printing

Healthy Identity Development Among Black Same-Gender Loving Men: A Mixed Methods Approach

Black Same-Gender Loving Men (BSGLM) are a population at the juncture of multiple marginalized identities, which may make it difficult to successfully form their identity due to experienced racism and heterosexism from communities to which they belong. Current paradigms of racial/ethnic and sexual identity do not fully capture the complexities of identity development among BSGLM. Moreover, there is scant literature available detailing what the process of identity development looks like among this population and which factors influence identity development among BSGLM. As such, the current study used an exploratory sequential mixed methods design to first discover what healthy identity looks like among BSGLM and which factors influence the process of developing a healthy identity. The study then empirically tested the elucidated factors in order to understand which of them influence identity development among BSGLM. First, a sample of BSGLM living in the U.S. (n = 19) were recruited via online and interviewed for the qualitative phase of the study about their identity development process. Using a Grounded Theory approach, the qualitative data revealed three unique components of healthy identity among BSGLM (e.g., self-affirmation, freedom from social conventions, having unconditional acceptance) and 13 factors that either inhibited or facilitated their identity development process. Qualitative findings were subsequently used to create a survey battery to quantitatively explore the relationships between the identified factors and components of healthy identity among another sample of BSGLM. The generated survey battery was administered to another sample of BSGLM living in the U.S. (n = 54) recruited from social media and organizations that service BSGLM. Bivariate correlations and multiple regression analyses examined inhibiting and facilitating factors as predictors of healthy identity. Findings revealed that minority stress-related factors were robust predictors of healthy identity. Specifically, rejection sensitivity from one’s family negatively predicted self-affirmation, frustration with concealing one’s sexual identity positively predicted freedom from social conventions, and experiencing threats/violence positively predicted unconditional acceptance. Results from the study may contribute to the refinement of identity development models among BSGLM and inform clinical interventions that bolster identity development among BSGLM such as transdiagnostic interventions that target minority stress and identity-related concerns

Discrimination, Coping, and Depression among Black Men Who Have Sex with Men

Black men who have sex with men (BMSM) have elevated risk for depression compared to the general population. BMSM’s capacity to cope with these experiences is not well understood. Increased understanding of how multiple forms of discrimination contribute to depression and how BMSM cope with discrimination can better inform interventions. Data come from 3,510 BMSM who attended Black Pride events in six U.S. cities from 2015-2017. Participants completed a health survey that ascertained their psychosocial health and resiliency profiles. Using multivariable logistic regression models, we tested the associations between type-specific discrimination (race, sexuality, HIV status) and depression. We then conducted sub-analyses to determine if coping attenuated the association between type-specific discrimination and depression. Our findings indicated that increased odds of depression among BMSM were associated with discrimination based on race (aOR=1.38, 95% CI = 1.08-1.76), sexual orientation (aOR=1.32, 95% CI = 1.01-1.72), and HIV status (aOR=1.53, 95% CI = 1.08-2.17). Sub-analyses indicated coping had inconsistent moderation effects between type-specific discrimination and depression. Our findings demonstrate that impact of various forms of discrimination on BMSM’s mental health and the mitigating role of coping. Interventions should seek to address depression by reducing experiences of discrimination and building coping resiliency

Addressing the Health Needs of Rural Native Veterans: Assessment and Recommendations

Native Veterans comprise unique populations within the VeteransAdministration (VA) system of care and represent a proud tradition of military service. Limited healthcare data available on rural Native veterans indicate significant disparities in access to care and health status compared with other populations. This article provides an assessment of current challenges, barriers, and issues related to addressing the healthcare needs of rural Native veterans and offers recommendations to improve healthcare for this special population. To meet the needs of rural Native veterans it will be important to: conduct needs assessments to gather important health data about rural Native veterans; develop a clearinghouse of information on and for rural Native veterans and disseminate this information widely; develop strategies to enhance transportation policies and provisions; expand the use of technology and outreach; work toward increasing cultural competence among VA employees; and improve the availability of traditional healing services

The impact of tuberculosis on the well-being of adolescents and young adults

The health needs of adolescents and young adults (AYAs) have been neglected in tuberculosis (TB) care, control, and research. AYAs, who are distinct from younger children and older adults, undergo dynamic physical, psychological, emotional, cognitive, and social development. Five domains of adolescent well-being are crucial to a successful transition between childhood and adulthood: (1) Good health; (2) connectedness and contribution to society; (3) safety and a supportive environment; (4) learning, competence, education, skills, and employability; and (5) agency and resilience. This review summarizes the evidence of the impact of TB disease and treatment on these five domains of AYA well-being

Overview of the MOSAiC expedition-Atmosphere INTRODUCTION

With the Arctic rapidly changing, the needs to observe, understand, and model the changes are essential. To support these needs, an annual cycle of observations of atmospheric properties, processes, and interactions were made while drifting with the sea ice across the central Arctic during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition from October 2019 to September 2020. An international team designed and implemented the comprehensive program to document and characterize all aspects of the Arctic atmospheric system in unprecedented detail, using a variety of approaches, and across multiple scales. These measurements were coordinated with other observational teams to explore crosscutting and coupled interactions with the Arctic Ocean, sea ice, and ecosystem through a variety of physical and biogeochemical processes. This overview outlines the breadth and complexity of the atmospheric research program, which was organized into 4 subgroups: atmospheric state, clouds and precipitation, gases and aerosols, and energy budgets. Atmospheric variability over the annual cycle revealed important influences from a persistent large-scale winter circulation pattern, leading to some storms with pressure and winds that were outside the interquartile range of past conditions suggested by long-term reanalysis. Similarly, the MOSAiC location was warmer and wetter in summer than the reanalysis climatology, in part due to its close proximity to the sea ice edge. The comprehensiveness of the observational program for characterizing and analyzing atmospheric phenomena is demonstrated via a winter case study examining air mass transitions and a summer case study examining vertical atmospheric evolution. Overall, the MOSAiC atmospheric program successfully met its objectives and was the most comprehensive atmospheric measurement program to date conducted over the Arctic sea ice. The obtained data will support a broad range of coupled-system scientific research and provide an important foundation for advancing multiscale modeling capabilities in the Arctic.Peer reviewe

The Impact of Tuberculosis on the Well-Being of Adolescents and Young Adults.

The health needs of adolescents and young adults (AYAs) have been neglected in tuberculosis (TB) care, control, and research. AYAs, who are distinct from younger children and older adults, undergo dynamic physical, psychological, emotional, cognitive, and social development. Five domains of adolescent well-being are crucial to a successful transition between childhood and adulthood: (1) Good health; (2) connectedness and contribution to society; (3) safety and a supportive environment; (4) learning, competence, education, skills, and employability; and (5) agency and resilience. This review summarizes the evidence of the impact of TB disease and treatment on these five domains of AYA well-being

Negative life events and suicide risk in college students: Conditional indirect effects of hopelessness and self-compassion

Objective: Suicide risk is a significant public health concern for college students and may be exacerbated by hopelessness resulting from negative life events (NLE), yet may be ameliorated by self-compassion. We examined the mediating role of hopelessness in the relation between NLE and suicidal behavior, and the moderating influence of self-compassion on all model paths. Participants: Participants were 338 undergraduates (89% white; 67% female). Data were collected from December 2014 to December 2015. Methods: Participants completed the Life Events Checklist for College Students, Beck Hopelessness Inventory, Self-Compassion Scale, and Suicidal Behaviors Questionnaire – Revised. Results: Negative life events were related to greater hopelessness and, in turn, to more suicidal behavior, yet self-compassion attenuated this effect. Conclusions: Self-compassion may buffer the NLE–hopelessness linkage, thereby reducing suicide risk among college students. Therapeutic promotion of self-compassion, and reduction of hopelessness, may be important suicide prevention strategies on college campuses

Bayesian analysis of Jolly-Seber type models; Incorporating heterogeneity in arrival and departure

We propose the use of finite mixtures of continuous distributions in modelling the process by which new individuals, that arrive in groups, become part of a wildlife population. We demonstrate this approach using a data set of migrating semipalmated sandpipers (Calidris pussila) for which we extend existing stopover models to allow for individuals to have different behaviour in terms of their stopover duration at the site. We demonstrate the use of reversible jump MCMC methods to derive posterior distributions for the model parameters and the models, simultaneously. The algorithm moves between models with different numbers of arrival groups as well as between models with different numbers of behavioural groups. The approach is shown to provide new ecological insights about the stopover behaviour of semipalmated sandpipers but is generally applicable to any population in which animals arrive in groups and potentially exhibit heterogeneity in terms of one or more other processes

Assessing Natural Resource Use by Forest-Reliant Communities in Madagascar Using Functional Diversity and Functional Redundancy Metrics

Biodiversity plays an integral role in the livelihoods of subsistence-based forest-dwelling communities and as a consequence it is increasingly important to develop quantitative approaches that capture not only changes in taxonomic diversity, but also variation in natural resources and provisioning services. We apply a functional diversity metric originally developed for addressing questions in community ecology to assess utilitarian diversity of 56 forest plots in Madagascar. The use categories for utilitarian plants were determined using expert knowledge and household questionnaires. We used a null model approach to examine the utilitarian (functional) diversity and utilitarian redundancy present within ecological communities. Additionally, variables that might influence fluctuations in utilitarian diversity and redundancy—specifically number of felled trees, number of trails, basal area, canopy height, elevation, distance from village—were analyzed using Generalized Linear Models (GLMs). Eighteen of the 56 plots showed utilitarian diversity values significantly higher than expected. This result indicates that these habitats exhibited a low degree of utilitarian redundancy and were therefore comprised of plants with relatively distinct utilitarian properties. One implication of this finding is that minor losses in species richness may result in reductions in utilitarian diversity and redundancy, which may limit local residents' ability to switch between alternative choices. The GLM analysis showed that the most predictive model included basal area, canopy height and distance from village, which suggests that variation in utilitarian redundancy may be a result of local residents harvesting resources from the protected area. Our approach permits an assessment of the diversity of provisioning services available to local communities, offering unique insights that would not be possible using traditional taxonomic diversity measures. These analyses introduce another tool available to conservation biologists for assessing how future losses in biodiversity will lead to a reduction in natural resources and provisioning services from forests