NEUDOSE: NEUtron DOSimetry & Exploration - A CubeSat for Dosimetry of Charged and Neutral Particles

Radiation hazard is a major concern for astronauts, especially as we look beyond LEO. We require a method for real-time measurements of both charged and neutral radiation for personal dosimetry. Large uncertainties in current data mostly due to radiation quality and dose-rate effects

Passive Attitude Control to Decrease CubeSatellite Complexity

Attitude control is often a requirement for the optimal functionality of satellite payloads. The McMaster Neutron Dosimetry and Exploration (NEUDOSE) mission aims to measure charged and neutral radiation in Low Earth Orbit. NEUDOSE can detect particles effectively from any direction due to its spherical symmetry, meaning unlike most satellite missions, it does not require attitude control to function. The attitude is still crucial for the mission in order to achieve optimal communication. The NEUDOSE satellite utilizes Ultra High Frequency and Very High Frequency dipole antennas for communication. If the satellite’s attitude lines up in a specific orientation, communication will be hindered due to the nature of the antenna’s radiation pattern. With short access times to the ground station, and relatively small amounts of data being transferred, effective communication is important for the success of the mission. Initially the NEUDOSE mission had an active attitude control system, but with the lack of pointing requirements for the payload’s operation, and a stringent power budget, the active system was removed. A passive magnetic attitude control system was then explored as a solution to optimize communication, without adding much complexity or burden on the power budget

Design of a Custom Secondary On-Board Computer for the NEUDOSE CubeSat Mission

The NEUtron DOSimetry & Exploration (NEUDOSE) CubeSat is the first small satellite mission from McMaster University. The mission includes two on-board computers (OBCs): a commercial off-the-shelf (COTS) board as the primary OBC, and a custom student-designed board, the secondary on-board computer (SOBC), as a secondary payload to the mission

Pregnancy and Mental Health of Young Homeless Women

Pregnancy rates among women in the U.S. who are homeless are much higher than rates among women who are housed (Greene & Ringwalt, 1998). Yet little research has addressed mental health, risk and resilience among young mothers who are homeless. This study utilizes a sample of women from the Midwest Longitudinal Study of Homeless Adolescents (MLSHA) to investigate pregnancy and motherhood over three years among unaccompanied homeless young mothers. Our data are supplemented by in-depth interviews with a subset of these women. Results show that almost half of sexually active young women (n = 222, μ age = 17.2) had been pregnant at baseline (46.4%), and among the longitudinal subsample of 171 women (μ age = 17.2), almost 70.0% had been pregnant by the end of the study. Among young mothers who are homeless, only half reported that they helped to care for their children consistently over time, and one-fifth of the women reported never seeing their children. Of the young women with children in their care at the last interview of the study (Wave 13), almost one-third met criteria for lifetime major depressive episode (MDE), lifetime posttraumatic stress disorder (PTSD), and lifetime drug abuse, and onehalf met criteria for lifetime antisocial personality disorder (APD). Twelve-month diagnoses are also reported. The impacts of homelessness on maternal and child outcomes are discussed, including the implications for practice, policy, and research

Image Analysis of Structured Surfaces for Quantitative Topographical Characterization

In the fields of functional materials, interfacial chemistry, and microscale devices, surface structuring provides an opportunity to engineer materials with unique tunable properties such as wettability, anti-fouling, crack propagation, and specific surface area. Often, the resulting properties are related to the feature sizes of the structured surfaces and therefore, it is necessary to accurately quantify these topographies. This work presents a step-by-step description of a method for the quantification of the size of periodic structures using 2D discrete Fourier Transform analysis coupled with data filtering techniques to optimize feature size extraction and reduce user bias and error. The method is validated using artificial images of periodic patterns as well as scanning electron microscopy images of gold films that are structured on different substrates. While image Fourier Transform has been used previously and is a built-in feature in some commercial and open-source image analysis software, this work details image pre-processing and feature extraction steps, and how to best apply them, which has not been described in detail elsewhere. This method can analyze engineered or natural periodic topographies (e.g., wrinkles) to enable the design of patterned materials for applications including photovoltaics, biosensors, tissue engineering, flexible electronics, and thin film metrology.</p