Selected On-Demand Medical Applications of 3D-Printing for Long-Duration Manned Space Missions

Recent technological advances in the area of Additive Manufacturing (i.e. 3D printing) allow for exploration of their use within long-duration manned space missions. Among the many potential application domains, medical and dental fabrication in support of crew health is of interest to NASA’s Advanced Exploration Systems directorate. A classification of medical events with their associated response timeline discern between those applications where current 3D printing technologies can provide adequate support. Products and devices that require on-demand fabrication (due to the high level of personal customization) but that can wait for a reasonable (e.g. few hours) fabrication time are the most promising areas. Among these non-emergency, on-demand applications, two were identified for further investigation: dental health and pharmaceutical drugs. A discussion on the challenges presented by a microgravity operational environment on these technologies is provided

Development Of Master’s Programs In Sustainable Engineering

During the 2006-2007 academic year, a team of faculty from the Kate Gleason College of Engineering developed a proposal for a pair of Master’s programs (a Master of Science program and a Master of Engineering proposal) in the field of Sustainable Engineering. Sustainable Engineering has been described as “engineering for human development that meets the needs of the present without compromising the ability of future generations to meet their own needs” [3]. Both programs are multidisciplinary in nature and include coursework from the disciplines of Industrial and Systems Engineering, Mechanical Engineering, Civil Engineering Technology, and Public Policy. The programs offer students the flexibility to develop ‘tracks’ in their program of study which would permit deeper immersion in domains such as renewable energy systems, systems modeling and analysis, product design, etc. Student interest in the programs has been very favorable. This paper describes the context at RIT from which the idea for these programs arose, the program development process that was followed, and the structure of the two programs

Geometric Modeling of Engineered Abrasive Processes

One of the common issues that arises in abrasive machining is the inconsistency of the surface roughness within the same batch and under identical machining conditions. Recent advances in engineered abrasives have allowed replacement of the random arrangement of minerals on conventional belts with precisely shaped structures uniformly cast directly onto a backing material. This allows for abrasive belts that are more deterministic in shape, size, distribution, orientation, and composition. A computer model based on known tooling geometry was developed to approximate the asymptotic surface profile that was achievable under specific loading conditions. Outputs included the theoretical surface parameters, R^sub q^, R^sub a^, R^sub v^, R^sub p^, R^sub t^, and R^sub sk^. Experimental validation was performed with a custom-made abrader apparatus and using engineered abrasives on highly polished aluminum samples. Interferometric microscopy was used in assessing the surface roughness. Results include the individual effects of pyramid base width, pyramid height, attack angle, and indentation depth on the surface descriptors

Multilobular tumor of the zygomatic bone in a dog

Multilobular tumor of bone (MTB) (also known as Multilobular Osteochondrosarcoma) is an uncommon bone tumor frequently located on the skull of dogs, rarely on the ribs or pelvis. These neoplasms are slow growing, locally invasive, and have the potential to compress and invade the brain. A 10-year-old mixed breed dog was presented with a history of approximately 4 months of progressive growth of a left zygomatic mass. Radiographic investigation revealed a finely granular or stippled non homogeneous radiopaque mass involving the zygomatic arch. After surgery, grossly the neoplasm consisted of multiple, variably sized, grayish-white to yellow nodules separated by collagenous septa of different thickness. Histologically, the tumor was characterized by the presence of multiple lobules containing osteoid and cartilage, separated by a net of fibrous septae. This neoplastic pattern was consistent with a typical multilobular tumor of bone and based on clinical, radiographical, gross and light microscopic findings the definitive diagnosis was made. While reviewing veterinary literature only few cases of MTB were found in dogs

Design, Implementation, And Integration Of An Experiential Assembly System Engineering Laboratory Module

Curriculum integration and multidisciplinary studies have become key issues in improving engineering education. This paper presents the design and implementation of laboratory material that integrates three traditionally independent courses in the industrial engineering curriculum, manufacturing, ergonomics, and simulation, utilizing an experiential assembly system. This collaborative project incorporates a team-based learn-by-doing approach to the theoretical knowledge in these subject areas1,3. These components are implemented in a dynamic and reconfigurable environment in which the students are given the opportunity of contrasting his/her design against the working reality. The results of this project are discussed along with the impact on the curriculum

An MIP Approach to the U-line Balancing Problem With Proportional Worker Throughput

One of the major challenges faced by manufacturing companies is to remain competitive in dynamic environments, where fluctuations in customer demand and production rates require systems capable of adapting in a practical and economical way. A U-shaped production cell is considered one of the most flexible designs for adapting the workforce level to varying conditions. However, re-balancing efforts are time consuming and often require a new work allocation and line design. In this paper, a two-stage MIP model to determine the best cell design under varying workforce levels is proposed. The model seeks to maintain proportionality between throughput and the number of workers. Computational experiments considering various line configurations (up to 19 stations) and workloads (up to 79 tasks) are performed. The results show the proposed algorithm provides excellent results for all small and medium size problems addressed in this study, as well as for certain configurations of large problems. This approach can be used to generate lookup tables of line designs to help with quick reallocation of worker assignments on the shop floor and with minimal disruption

Modeling of Tooling-Workpiece Interactions on Random Surfaces

Abrasive processes, commonly employed in manufacturing, are difficult to model because they rely on brittle particles with unknown geometry and multiple points of contact. Newly developed microreplicated abrasives allow for control of abrasive grit properties such as size, shape, and distribution. This paper proposes and validates a parametric model of abrasive machining that allows for studying the interaction of this particular tooling with randomly generated surfaces. In this work, the parameters of a probability distribution function that represents the workpiece surface are approximated by profilometry data. Monte Carlo simulation is used to account for inter- and intraspecimen variability. A geometric representation is used to mathematically represent the interaction between workpiece and tool. The results show good correlation between theoretical and actual values. This approach could be used to aid in tool geometry design as well as in process parameter optimization

Analysis of very-high surface area 3D-printed media in a moving bed biofilm reactor for wastewater treatment

Moving Bed Biofilm Reactors (MBBRs) can efficiently treat wastewater by incorporating suspended biocarriers that provide attachment surfaces for active microorganisms. The performance of MBBRs for wastewater treatment is, among other factors, contingent upon the characteristics of the surface area of the biocarriers. Thus, novel biocarrier topology designs can potentially increase MBBR performance in a significant manner. The goal of this work is to assess the performance of 3-D-printed biofilter media biocarriers with varying surface area designs for use in nitrifying MBBRs for wastewater treatment. Mathematical models, rendering, and 3D printing were used to design and fabricate gyroid-shaped biocarriers with a high degree of complexity at three different levels of specific surface area (SSA), generally providing greater specific surface areas than currently available commercial designs. The biocarriers were inoculated with a nitrifying bacteria community, and tested in a series of batch reactors for ammonia conversion to nitrate, in three different experimental configurations: constant fill ratio, constant total surface area, and constant biocarrier media count. Results showed that large and medium SSA gyroid biocarriers delivered the best ammonia conversion performance of all designs, and significantly better than that of a standard commercial design. The percentage of ammonia nitrogen conversion at 8 hours for the best performing biocarrier design was: 99.33% (large SSA gyroid, constant fill ratio), 94.74% (medium SSA gyroid, constant total surface area), and 92.73% (large SSA gyroid, constant biocarrier media count). Additionally, it is shown that the ammonia conversion performance was correlated to the specific surface area of the biocarrier, with the greatest rates of ammonia conversion (99.33%) and nitrate production (2.7 mg/L) for manufactured gyroid biocarriers with a specific surface area greater than 1980.5 m2/m3. The results suggest that the performance of commercial MBBRs for wastewater treatment can be greatly improved by manipulation of media design through topology optimization

Cumulative Genetic and Environmental Predictors of Youth Substance Use

Thesis advisor: Rebekah Levine ColeySubstance abuse and dependence are among the nation's leading health issues, leading to more illnesses, disabilities, and deaths than any other modifiable health condition. Substance use among youth is of particular concern, as rates are higher than among any other age group and because early use is associated with a higher risk of later abuse and dependence and a higher incidence of related risk-taking behavior. Thus, a better understanding of the causes of substance use problems is a central issue. The primary goal of this study was to examine genetic and environmental predictors of youth alcohol and drug abuse and dependence. This study expands upon extant research by being the first to utilize a genetic risk score (GRS) approach to examine the joint effect of four dopaminergic genetic polymorphisms on substance abuse and dependence, by incorporating cumulative measures of environmental risk and promotive factors, and by examining gene-environment interactions (GxEs) and gender differences in substance use predictors, thus allowing for a more comprehensive assessment of environmental and genetic influences than has previously been attempted. Analyses were conducted on a national longitudinal sample of 1,396 Caucasian youth who participated in surveys and DNA sampling in the National Longitudinal Study of Adolescent Health, with individuals followed from adolescence (ages 12-18) into early adulthood (ages 24-32). Logistic regression analyses examined main and interactive effects of cumulative environmental risk and promotive factors and genetic risk scores on clinically significant alcohol and drug abuse and dependence in early adulthood. Analyses were conducted separately for males and females to examine gender differences in substance use predictors. Results show that a dopaminergic GRS index significantly predicted the likelihood that female, but not male, youth will meet clinical criteria for substance abuse and dependence, even after accounting for cumulative environmental influences. No evidence of GxE was found. These results provide a better understanding of the etiology of substance abuse and dependence and provide evidence of the utility of GRS methods for studying genetic influences on substance use behaviors.Thesis (PhD) — Boston College, 2012.Submitted to: Boston College. Lynch School of Education.Discipline: Counseling, Developmental, and Educational Psychology