Final Design Report: Design and Development of an Ackermann Steering Geometry for a Formula SAE Car

The steering system was designed to be implemented in Trinity’s Formula SAE racecar. All design choices were made first with respect to the FSAE rules and then to the team’s production capabilities (manufacturing skill level and the limitations of Trinity’s machine shop equipment). The system was first evaluated by its compliance with FSAE rules: limited degrees of free play, quick release safety compliance, and the clearance of the cockpit template, front uprights, and wheel rims. The next feature that was evaluated was the car’s ability to navigate a hairpin turn. The steering system was evaluated by its toe in/out, steering ratio, and Ackermann percentage. At low speeds, Ackerman geometries improve the cornering ability in fast, technical tracks. Test 1 evaluated the free play present in the steering system. FSAE mandates that there be no greater than 7 degrees of free play. The car successfully passed Test 1 revealing that on average there are only 5 degrees of free play in the steering system. Test 2 assessed the car’s ability to navigate both clockwise and counterclockwise hairpin turns by comparing the actual operating range with previously computed minimum inner and outer toe angles. The operating angles exceeded the minimum steering angles; therefore, the car should be able to navigate all turns in the Autocross and Skidpad events. Test 3 was designed to mimic the track at the annual FSAE competition. The powertrain subsystem remains incomplete, so the car is to be pushed by design team members while another member steers the vehicle. Due to a recent unexpected break in the left front A-arm of the suspension, Test 3 has not been performed. Test 4 assessed the function of the quick release, cockpit ergonomics, and the ability of a driver to safely exit the vehicle in 9 seconds. Thirty trials by three different drivers demonstrate the success of the quick release feature and the ability to exit the vehicle in far less than 9 seconds. A primary objective of this senior design project was to meet FSAE guidelines and create a robust system that can be optimized by future senior design teams. Given that the steering system passed the 3 tests that were performed, it is clear that we have produced a working steering system that will provide a strong basis for the next team that continues to prepare the car for competition. Another objective was to produce the car while cognizant of the different FSAE events that the TUMS car will eventually compete in. Two other objectives were to follow a thorough design process for the steering system and to maintain records of design decisions, engineering drawings, and inventory for future students who will work on the car. Throughout the process the team kept organized notes on materials, vendors, purchases, and decisions. Two more objectives were to fabricate and assemble the steering system and implement a placeholder for the incomplete suspension system. Both objectives were met: the steering system is complete and two wooden blocks were placed next to the uprights to support the car in lieu of a function suspension system for testing.. A final primary objective was to dynamically test the steering system (Test 3), but this was not met. Several welds must be repaired before Test 3 can be safely performed. All welds on the suspension and powertrain should be evaluated and strengthened if needed before dynamic testing should proceed. A secondary objective (not formally evaluated) was to manage the implementation of a braking system to be completed by the current TUMS members. All components of the braking system have been ordered and received. There is a plan for the assembly, but there were not as many active and available TUMS members as anticipated so it has not been completed. To achieve a fully-implemented braking system, all parts should be assembled and plumbing lines purchased and strategically attached. The final goal was to integrate and complete as much of the previously designed subsystems as possible (powertrain, suspension, electronics, etc.). Much research and many steps have been taken towards this objective, but there is a significant future work necessary to achieve a running powertrain and integrated, functional car

Quantitative trait loci conferring grain mineral nutrient concentrations in durum wheat 3 wild emmer wheat RIL population

Mineral nutrient malnutrition, and particularly deficiency in zinc and iron, afflicts over 3 billion people worldwide. Wild emmer wheat, Triticum turgidum ssp. dicoccoides, genepool harbors a rich allelic repertoire for mineral nutrients in the grain. The genetic and physiological basis of grain protein, micronutrients (zinc, iron, copper and manganese) and macronutrients (calcium, magnesium, potassium, phosphorus and sulfur) concentration was studied in tetraploid wheat population of 152 recombinant inbred lines (RILs), derived from a cross between durum wheat (cv. Langdon) and wild emmer (accession G18-16). Wide genetic variation was found among the RILs for all grain minerals, with considerable transgressive effect. A total of 82 QTLs were mapped for 10 minerals with LOD score range of 3.2–16.7. Most QTLs were in favor of the wild allele (50 QTLs). Fourteen pairs of QTLs for the same trait were mapped to seemingly homoeologous positions, reflecting synteny between the A and B genomes. Significant positive correlation was found between grain protein concentration (GPC), Zn, Fe and Cu, which was supported by significant overlap between the respective QTLs, suggesting common physiological and/or genetic factors controlling the concentrations of these mineral nutrients. Few genomic regions (chromosomes 2A, 5A, 6B and 7A) were found to harbor clusters of QTLs for GPC and other nutrients. These identified QTLs may facilitate the use of wild alleles for improving grain nutritional quality of elite wheat cultivars, especially in terms of protein, Zn and Fe

Phenotypic Diversity for Seed Mineral Concentration in North American Dry Bean Germplasm of Middle American Ancestry

Dry bean (Phaseolus vulgaris L.) seeds are a major protein, carbohydrate, and mineral source in the human diet of peoples in multiple regions of the world. Seed mineral biofortification is an ongoing objective to improve this important food source. The objective of this research was to assess the seed mineral concentration of five macroelements and eight microelements in a large panel (n = 277) of modern race Durango and race Mesoamerica genotypes to determine if variability existed that could be exploited for targeted seed biofortification. Varieties that derive from these races are found in many diets throughout the world. The panel was grown in replicated trials under typical production conditions in the major bean growing regions of the United States, and a subset of the panel was also grown in replicated trials at three locations under control and terminal drought conditions. Except for K, seed mineral concentrations were higher for race Mesoamerica genotypes. Significantly higher seed concentrations for the majority of the minerals were observed for white-seeded genotypes and race Durango genotypes with the now preferred indeterminate, upright growth habit. Modern genotypes (since 1997) had equal or increased mineral concentrations compared with older genotypes. Drought affected mineral content differentially, having no effect on the microelement content but increased Co, Fe, and Ni concentrations. The correlation of Ca and Mn concentrations suggests that these elements may share seed deposition mechanisms. The high heritability for seed mineral concentration implies that breeding progress can be achieved by parental selection from this panel

Arabidopsis Glutaredoxin S17 Contributes to Vegetative Growth, Mineral Accumulation, and Redox Balance during Iron Deficiency

Iron (Fe) is an essential mineral nutrient and a metal cofactor required for many proteins and enzymes involved in the processes of DNA synthesis, respiration, and photosynthesis. Iron limitation can have detrimental effects on plant growth and development. Such effects are mediated, at least in part, through the generation of reactive oxygen species (ROS). Thus, plants have evolved a complex regulatory network to respond to conditions of iron limitations. However, the mechanisms that couple iron deficiency and oxidative stress responses are not fully understood. Here, we report the discovery that an Arabidopsis thaliana monothiol glutaredoxin S17 (AtGRXS17) plays a critical role in the plants ability to respond to iron deficiency stress and maintain redox homeostasis. In a yeast expression assay, AtGRXS17 was able to suppress the iron accumulation in yeast ScGrx3/ScGrx4 mutant cells. Genetic analysis indicated that plants with reduced AtGRXS17 expression were hypersensitive to iron deficiency and showed increased iron concentrations in mature seeds. Disruption of AtGRXS17 caused plant sensitivity to exogenous oxidants and increased ROS production under iron deficiency. Addition of reduced glutathione rescued the growth and alleviates the sensitivity of atgrxs17 mutants to iron deficiency. These findings suggest AtGRXS17 helps integrate redox homeostasis and iron deficiency responses

Elevated copper impairs hepatic nuclear receptor function in Wilson’s disease

Wilson's disease (WD) is an autosomal recessive disorder that results in accumulation of copper in the liver as a consequence of mutations in the gene encoding the copper-transporting P-type ATPase (ATP7B). WD is a chronic liver disorder, and individuals with the disease present with a variety of complications, including steatosis, cholestasis, cirrhosis, and liver failure. Similar to patients with WD, Atp7b⁻/⁻ mice have markedly elevated levels of hepatic copper and liver pathology. Previous studies have demonstrated that replacement of zinc in the DNA-binding domain of the estrogen receptor (ER) with copper disrupts specific binding to DNA response elements. Here, we found decreased binding of the nuclear receptors FXR, RXR, HNF4α, and LRH-1 to promoter response elements and decreased mRNA expression of nuclear receptor target genes in Atp7b⁻/⁻ mice, as well as in adult and pediatric WD patients. Excessive hepatic copper has been described in progressive familial cholestasis (PFIC), and we found that similar to individuals with WD, patients with PFIC2 or PFIC3 who have clinically elevated hepatic copper levels exhibit impaired nuclear receptor activity. Together, these data demonstrate that copper-mediated nuclear receptor dysfunction disrupts liver function in WD and potentially in other disorders associated with increased hepatic copper levels