Extension of Generalized Fluid System Simulation Program's Fluid Property Database

This internship focused on the development of additional capabilities for the General Fluid Systems Simulation Program (GFSSP). GFSSP is a thermo-fluid code used to evaluate system performance by a finite volume-based network analysis method. The program was developed primarily to analyze the complex internal flow of propulsion systems and is capable of solving many problems related to thermodynamics and fluid mechanics. GFSSP is integrated with thermodynamic programs that provide fluid properties for sub-cooled, superheated, and saturation states. For fluids that are not included in the thermodynamic property program, look-up property tables can be provided. The look-up property tables of the current release version can only handle sub-cooled and superheated states. The primary purpose of the internship was to extend the look-up tables to handle saturated states. This involves a) generation of a property table using REFPROP, a thermodynamic property program that is widely used, and b) modifications of the Fortran source code to read in an additional property table containing saturation data for both saturated liquid and saturated vapor states. Also, a method was implemented to calculate the thermodynamic properties of user-fluids within the saturation region, given values of pressure and enthalpy. These additions required new code to be written, and older code had to be adjusted to accommodate the new capabilities. Ultimately, the changes will lead to the incorporation of this new capability in future versions of GFSSP. This paper describes the development and validation of the new capability

Rise of the Yuan: Export Similarity and Comparisons to the Yen

According to recent studies, the yuan has become a reference currency rivaling the US dollar in East Asia within the past decade. The yen never gained enough influence to challenge that of the dollar despite holding a similar share of trade 20 years ago as China does now in the region. This paper asks why the yuan became a reference currency in East Asia while the yen did not 20 years ago. This study hypothesizes that a reason for this discrepancy is that China competes more with its neighbors today than Japan did 20 years ago. In order to test this hypothesis, this study uses an export similarity method developed by Finger and Kreinin (1979) alongside a multiple regression analysis. The data indicates that export similarity plays a major role in increasing regional currency influence. As a result, this paper finds a developmental difference between the renminbi and yen

Case Study of Metformin-Induced Lactic Acidosis

Metformin induced lactic acidosis is when high levels of metformin cause dangerously high levels of lactic acid. Here is a case report of a 72-year-old female who came in for nausea, vomiting, and diarrhea found to have a high suspicion for metformin induced lactic acidosis. She stabilized in the emergency department, nephrology and ICU was contacted, and she went for emergent dialysis. For many patients the prognosis of metformin induced lactic acidosis is poor. This patient was made comfort care by her family

An Unusual ED Case: Spontaneous Necrotizing Fasciitis Presenting as Hypoxic Pneumonia

We present a case of necrotizing fasciitis initially presenting as septic hypoxic pneumonia, and discuss imaging modalities and diagnostic evaluation. Necrotizing soft tissue infection (NSTI) is a rapidly progressive surgical emergency with a mortality rate of 30%. In approximately 80% of cases, it is introduced through a break in the skin. It can also occur after any invasive procedure or surgery. It is most commonly associated with skin flora including staph and strep, though polymicrobial infections are most common. It usually presents with signs of systemic infection, including fever, chills, sepsis, altered mental status - and signs of cutaneous involvement on physical exam, including erythema / discoloration, sloughing and blistering, and pain out of proportion to exam, and crepitus. The crepitus or findings of subcutaneous emphysema on imaging are due to gas-producing bacteria from polymicrobial infection. Blood work can help support the diagnosis of a systemic infection, including things like elevated white blood cell count, elevated lactic acidosis, and other systemic inflammatory markers. Imaging can show signs of free air, particularly on x-ray, ultrasound, or CT. Poor prognosis is associated with comorbidities, advanced age, immunocompromised state, shock. The definitive treatment is early surgical debridement of the necrosed tissue, and antibiotics. Surgical exploration usually confirms the diagnosis, with foul gray fluid expressed, necrosis and gangrene of underlying tissues and muscles, and friability of muscles on dissection. Hypoxia and tachypnea can have a broad differential diagnosis, including but not limited to reactive airway disease, heart failure, pneumonia, pulmonary emboli. In the setting of fever and cough, a working clinical diagnosis of pneumonia can be considered

Case Report: Splenic Infarct s/p Sleeve Gastrectomy

A case of splenic infarct s/p sleeve gastrectomy is presented. A 28-year-old female presented with LUQ pain s/p sleeve gastrectomy POD7. CT scan with IV contrast revealed an area of nonenhancement at the superomedial aspect of the spleen consistent with a small splenic infarct. She was transferred out to the hospital under the service of the surgeon who had performed her sleeve gastrectomy. Splenic infarction is a rare post-op complication s/p sleeve gastrectomy. The spleen has dual blood supply via the splenic artery and short gastric arteries making complete infarction rare. It is usually diagnosed via CT with IV contrast. The aim of this case report is to the increase the awareness of splenic infarction as a potential complication s/p bariatric surgery

Purple Urine Bag Syndrome (PUBS) in a Patient with a Chronic Indwelling Foley

Purple urine bag syndrome (PUBS) is a rare medical condition characterized by the appearance of purple discoloration in the urine collection bag of patients who use catheters for urinary drainage. PUBS is primarily seen in elderly, female, and institutionalized patients who have chronic indwelling catheters. The discoloration occurs due to the presence of certain bacteria that produce pigments, which react with the plastic materials of the catheter and urine collection bag, leading to the formation of a purple color. In addition to the aesthetic concerns, PUBS may also indicate an underlying urinary tract infection or other medical conditions that require immediate attention. This case report provides an overview of PUBS, including its etiology, pathogenesis, clinical manifestations, and management

Path Planning with Power Schedules for Solar-Powered Ground Robot

This Research examines an integrated path planning and power management problem for a solarpowered unmanned ground vehicle (UGV). The proposed method seeks to minimize the travel time of the UGV through a given static area by both designing an optimal path and allocating the obtained power among the electrical components. Two types of path planes are examined in this research: a differential drive and pseudo-dubins. The UGV is operating under strict power constraints while harvesting ambient environmental energy along the designed path. A scalar field is first established to evaluate the solar radiation density at discrete locations. A modified Particle Swarm Optimization method is applied to search for a minimal time path wherein the energy gathered is equal to or greater than the energy expended. The proposed modeling and optimization strategy is verified through computer simulation and test bed demonstration. Current and future work is also examined in the areas of a continuous smooth curve and alternative methods of capturing the solar density that will potential allow for constant updating and dynamic area path planning

A Novel Case of HHV-6 Meningoencephalitis in an Immunocompetent Adult

We present a case of a 56-year-old female who presented with HHV6 encephalitis. She initially presented with altered mental status. Our patient ultimately made a full recovery several days later with only some mild intermittent episodes of confusion. Currently there are no other case reports of HHV6 encephalitis in the adult population

Determination of the hydrogen peroxide concentration in rotenone induced dopaminergic cells using cyclic voltammetry and amplex red

Parkinson\u27s disease (PD) is a neurodegenerative condition that affects millions of people worldwide. The exact etiology of PD is unknown. However, it is well established that environmental factors contribute to the onset of PD. In particular, chemicals such as the insecticide Rotenone have been shown to increase the death of dopaminergic (DA) neurons by increasing levels of reactive oxygen species (ROS). ROS such as hydrogen peroxide (H2O2) have been shown to be elevated above basal levels in PD patients. Currently, to measure H2O2 concentrations, a commercially available (Amplex® Red) fluorescent assay is used. However, the assay has limitations: it is not completely specific to hydrogen peroxide and can only measure extracellular ROS concentrations. This research focuses on testing an electrochemical sensor that uses cyclic voltammetry to quantitatively determine concentrations of H2O2 released from a cell culture. The sensor was first tested in normal cell culture conditions. Next, chemical interference was reduced and the sensor was optimized for accuracy by altering protein concentrations in the media. Finally, Rotenone was added to a cell culture to induce H2O2 production. Near real-time measurements of H2O2 were taken using the sensor and comparisons made to the fluorescent assay method. Overall, we are trying to determine if the electrochemical sensor can selectively and quantitatively measure H2O2 released from cells. Being able to track the production, migration and concentration of H2O2 in a cell can help researchers better understand its mechanism of action in cell death and oxidative damage, thus getting closer to finding a cure for PD

Thyrotoxic Periodic Paralysis: A Case Report and Discussion of Clinical and Imaging Features

Thyrotoxic Periodic Paralysis (TPP) is a rare manifestation of thyrotoxicosis, resulting in periodic episodes of acute onset muscle weakness in the setting of hypokalemia. The thyrotoxic form of Hypokalemic Periodic Paralysis (HPP) is less studied than the more well-known familial form due to fewer reported cases and smaller prevalence. This case study presents a 30-year-old African American male with multiple episodes of acute lower extremity muscle weakness, tachycardia, and a history of heat intolerance. Abnormal findings on thyroid ultrasound coupled with increased thyroid related immunoglobulins led to a diagnosis of TPP related to exacerbation of newly-found Graves’ disease. The case study will further discuss the importance of imaging in assessing the etiology of TPP with review of relevant literature