Simulation and Design Tool for Supermileage Vehicle (SMV) Club FINAL DESIGN REPORT

The purpose of this project is to create a sensitivities tool and start an optimization tool to assist the Cal Poly SMV Team in designing their vehicle, developing a driving strategy for competition, and becoming a contender in endurance events. The development of a user-friendly vehicle simulation and design tool was proposed by Professor Joseph Mello who is the club’s advisor. The SMV Team competes in endurance events such as the Supermileage competition or the Shell Eco-marathon with the goal of achieving the best mileage possible. This report will present the research that has been conducted to understand and define the problems this project attempts to solve. Included is information gained from customer interviews (members of SMV club and Professor Mello), existing simulation tools for vehicles such as GT-Suite and OptimumLap, and other relative findings pertaining to subjects like vehicle modeling and the Shell Eco-marathon competition. Two Masters theses are also explored due to their relevance in the design and simulation of the Cal Poly SMV’s prototype vehicles and other sources that cover topics like vehicle inertia and aerodynamic impacts on fuel efficiency are presented. The research also investigates how the world’s most fuel-efficient vehicle, the PAC car II, was developed and details the application of dynamic programming to find the optimum driving strategy. After summarizing the customer’s wants and needs to include the most relevant and important topics, the scope of the project is defined and engineering specifications that the tools will have to meet for this project to be considered successful are established. The specifications are separated into functional and nonfunctional requirements as is the standard practice for software design. Several alternative options were generated as part of the concept prototype and their pros and cons were weighed using a decision matrix to develop the final design. Some of the topics under discussion include modeling the engine, optimization method, and system representation. A few initial concepts were integrated into part of the final design such as the overall GUI layout as well as the road load calculator. For the final design of the simulation and design tool, a model of the vehicle is developed using higher level design parameters and the underlying physical principles governing vehicle performance. The sensitivities (design) tool investigates the effects of changing such parameters on the overall fuel consumption to help the SMV team optimize their design. The burn & coast optimization (simulation) tool attempts to find an ideal driving strategy that maximizes fuel-efficiency given a set of design inputs and track profile. It is to be noted that the burn & coast optimization tool is not completed in its entirety, but a detailed source of instruction to continue with the tool is provided. The end-user can operate the tools through an intuitive graphical user interface (GUI) that can easily be used by any Cal Poly student. There are several spreadsheet tools and templates that interface with the simulation and design tool through the GUI which include the road load calculator, engine performance data, and track profile. The required operating software for the project includes MATLAB 2019b and Microsoft Excel which are both provided by the school and is free of charge for any Cal Poly student. The manufacturing and validation procedures are introduced along with detailed timelines to complete the project before the end of Winter quarter deadline. Part of the validation occurs simultaneously with the development of individual modules such that during the assembly and final production phase, all inputs and outputs have been verified and within an acceptable margin of error. The final product will be tested thoroughly and destructively to leave little room for user error and system crash. User manuals of the product are also available to the SMV team to account for any confusion while using the product. Finally, relevant literature is introduced as part of the appendices

Formation of Warped Disks by Galactic Fly-by Encounters. I. Stellar Disks

Warped disks are almost ubiquitous among spiral galaxies. Here we revisit and test the `fly-by scenario' of warp formation, in which impulsive encounters between galaxies are responsible for warped disks. Based on N-body simulations, we investigate the morphological and kinematical evolution of the stellar component of disks when galaxies undergo fly-by interactions with adjacent dark matter halos. We find that the so-called `S'-shaped warps can be excited by fly-bys and sustained for even up to a few billion years, and that this scenario provides a cohesive explanation for several key observations. We show that disk warp properties are governed primarily by the following three parameters; (1) the impact parameter, i.e., the minimum distance between two halos, (2) the mass ratio between two halos, and (3) the incident angle of the fly-by perturber. The warp angle is tied up with all three parameters, yet the warp lifetime is particularly sensitive to the incident angle of the perturber. Interestingly, the modeled S-shaped warps are often non-symmetric depending on the incident angle. We speculate that the puzzling U- and L-shaped warps are geometrically superimposed S-types produced by successive fly-bys with different incident angles, including multiple interactions with a satellite on a highly elongated orbit.Comment: 16 pages, 13 figures, 3 tables. Accepted for publication in Ap

Hypertensive brainstem encephalopathy involving deep supratentorial regions: does only blood pressure matter?

We report on a 42-year-old female patient who presented with high arterial blood pressure of 245/150 mmHg and hypertensive brainstem encephalopathy that involved the brainstem and extensive supratentorial deep gray and white matter. The lesions were nearly completely resolved several days after stabilization of the arterial blood pressure. Normal diffusion-weighted imaging findings and high apparent diffusion coefficient values suggested that the main pathomechanism was vasogenic edema owing to severe hypertension. On the basis of a literature review, the absolute value of blood pressure or whether the patient can control his/her blood pressure seems not to be associated with the degree of the lesions evident on magnetic resonance imaging. It remains to be determined if the acceleration rate and the duration of elevated arterial blood pressure might play a key role in the development of the hypertensive encephalopathy pattern

Hemorrhagic pericarditis with cardiac tamponade after percutaneous coronary intervention associated with the use of abciximab

Glycoprotein (GP) IIb/IIIa inhibitors, such as abciximab, are used as adjunctive therapy for percutaneous coronary intervention (PCI) in high-risk non-ST-elevation myocardial infarction (NSTEMI) and in ST-elevation myocardial infarction (STEMI), although their effects when used for STEMI are less clear. As the use of GP IIb/IIIa inhibitors becomes more widespread, determining the risks associated with them becomes more important. The major risks associated with the use of GP IIb/IIIa inhibitors are the potential for major bleeding and thrombocytopenia. This is the first reported case in Korea of hemorrhagic pericarditis resulting in cardiac tamponade associated with the use of abciximab, a commonly used GP Ilb/IIa inhibitor, following PCI

Intracorporeal Anastomosis Using Linear Stapler in Laparoscopic Distal Gastrectomy: Comparison between Gastroduodenostomy and Gastrojejunostomy

Purpose: Intracorporeal anastomosis during laparoscopic gastrectomy is becoming increasingly prevalent. However, selection of the anastomosis method after laparoscopic distal gastrectomy is equivocal because of a lack of technical feasibility and safety. We compared intracorporeal gastroduodenostomy with gastrojejunostomy using linear staplers to evaluate the technical feasibility and safety of intracorporeal anastomoses as well as its' minimally invasiveness. Materials and Methods: Retrospective analyses of a prospectively collected database for gastric cancer revealed 47 gastric cancer patients who underwent laparoscopic distal gastrectomy with either intracorporeal gastroduodenostomy or gastrojejunostomy from March 2011 to June 2011. Perioperative outcomes such as operation time, postoperative complication, and hospital stay were compared according to the type of anastomosis. Postoperative inflammatory response was also compared between the two groups using white blood cell count and high sensitivity C-reactive protein. Results: Among the 47 patients, 26 patients received gastroduodenostomy, whereas 21 patients received gastrojejunostomy without open conversion or additional mini-laparotomy incision. There was no difference in mean operation time, blood loss, and length of postoperative hospital stays. There was no statistically significant difference in postoperative complication or mortality between two groups. However, significantly more staplers were used for gastroduodenostomy than for gastrojejunostomy (n=6) than for gastroduodenostomy and (n=5). Conclusions: Intracorporeal anastomosis during laparoscopic gastrectomy using linear stapler, either gastroduodenostomy or gastrojejunostomy, shows comparable and acceptable early postoperative outcomes and are safe and feasible. Therefore, surgeons may choose either anastomosis method as long as oncological safety is guaranteedope

Usefulness of serum lactate as a predictor of successful discontinuation of continuous atropine infusion in patients with severe acute organophosphate poisoning

Objective In severe organophosphate (OP) poisoning, administration of atropine via continuous intravenous infusion is typically considered. To date, there have been no studies on predicting successful atropine discontinuation through plasma cholinesterase (PChE) and serum lactate levels, which are monitored during critical care in severe acute OP poisoning. Therefore, we retrospectively evaluated the usefulness of serum lactate and PChE as predictors of successful discontinuation of atropine infusion. Methods This retrospective observational study was performed on consecutive adult patients treated for severe acute OP poisoning between March 2011 and December 2016. We sequentially evaluated serum lactate and PChE levels on emergency department arrival and before a discontinuation trial of atropine infusion. Discontinuation of atropine intravenous infusion was attempted in patients after clearance of respiratory secretions and cessation of bronchoconstriction. Discontinuation of atropine infusion attempts were divided into successful and failed trials. Results A total of 95 trials were conducted in 62 patients. Serum lactate levels before trials were significantly different between patients with successful and failed trials. The area under the curve for prediction of successful atropine discontinuation using serum lactate levels before trial discontinuation were 0.742 (95% confidence interval, 0.638 to 0.846). PChE level was not significantly different between two groups. Conclusion Serum lactate levels before the discontinuation trial of atropine infusion served to predict successful discontinuation in severe acute OP poisoning