Validation of CFD Tornado Pressure on Building and Wind Field with TTU Vortex Chamber Measurements

Structural failure of low-rise buildings is the root cause of higher number of casualties, death tolls and economic losses at the place of occurrence of tornadoes. Proper design of low-rise buildings in tornado-prone areas require accurate estimation of tornado-induced wind loads; however, exhaustive research to estimate the wind loads reliably on buildings during tornadic events is still lacking. Several studies have been carried out to investigate the magnitude of forces induced by tornado winds on buildings from experimental as well as computational side. However, the wind pressures obtained on the building from different experimental studies have shown significant variation from one study to another. Similarly, the wind pressures on the building from CFD simulation of tornado vortex often lacks comparison and/or validation with experimental data. Even the modeling of CFD tornado chamber and CFD flow validation is fraught with several challenges such as requirements of high-performance (or supercomputing) resources and lack of guidelines for validation of wind field of tornado vortex from CFD model. Thus, in this work, a simple yet an effective CFD tornado simulator model is developed, which provides comparable results with experiment without the necessity of supercomputing resources. This work also identifies and proposes four important features of tornado vortex (i.e., touchdown swirl ratio, core radius, the maximum tangential velocity & the elevation of maximum tangential velocity) including the ground pressure profile for validation of wind field obtained from CFD model. A comparative analysis of the four important vortex features from different tornado chambers and different work of literature is also presented. Lastly, the pressures induced by tornado vortex from CFD model on the building is validated with TTU experimental datasets. Furthermore, a detailed analysis on the effect of size of building, flow structure and Reynolds number of vortex on the induced wind pressures on the building is also presented

The Strategic Value Driver Model: a Methodology for Examining Value Drivers for a New Pharmaceutical Product in Diabetes

Objective. Objective The primary objective of this study was to explore a new methodological framework—Strategic Value Driver Model (SVDM), for examining value drivers for new pharmaceutical inhaled insulin in diabetes. Methods. A cross-sectional, internet-based survey was used to collect a sample of 483 Type 2 diabetic patients via national panel of diabetic patients. The sample had two subgroups—insulin-naïve (52.9%, n=255) and insulin-user (47.1%, n=227) patients. The comparative performance of insulin syringes/vials, insulin pen and inhaled insulin was captured on four product attributes (i.e., safety, convenience, clinical efficacy and cost) after asking the patients to report the importance of these attributes. The preference for inhaled insulin was used as dependent variable for running multivariable logistic regression with summated-scale score variables for the performance of the products as independent variables. Results. The respondents had an average age of 58 years. After considering product profiles and out-of-pocket monthly cost of three products, insulin pen and inhaled insulin were equally preferred products (by 36.9% and 36.3% of patients, respectively). The preference for inhaled insulin was significantly higher among insulin naïve patients (48.2% insulin naïve vs. 22.8% insulin users). Performance differentiation between inhaled and pen insulin on clinical efficacy and convenience significantly predicted the preference for inhaled insulin; whereas, performance differentiation between inhaled and syringe/vial insulin on clinical efficacy, safety and convenience significantly predicted the preference for inhaled insulin. A higher percentage of insulin naïve patients placed high importance on clinical efficacy, safety and convenience than insulin-user patients (76.9% vs. 65.8% for efficacy, 81.6% vs. 68.4% for safety, and 54.5% vs. 45.2% for convenience, respectively). The two subgroups were found to be different in terms of predictors for the preference of inhaled insulin. Conclusion. It will be critical for the manufacturer of new inhaled insulin to develop strategies to minimize out-of-pocket cost for the patient, along with promoting the clinical efficacy and safety of the new product. Furthermore, the results suggest that insulin naïve patients may be a potential market for this new inhaled insulin. A major limitation for this study was that almost all of the insulin-users had prior experience with Exubera (N=222, 97.4%)

Design and Simulation of an 8-Bit Successive Approximation Register Charge-Redistribution Analog-To-Digital Converter

The thesis initially investigates the history of the monolithic ADCs. The next chapter explores the different types of ADCs available in the market today. Next, the operation of a 4-bit SAR ADC has been studied. Based on this analysis, an 8-bit charge-redistribution SAR ADC has been designed and simulated with Multisim (National Instruments, Austin, TX). The design is divided into different blocks which are individually implemented and tested. Level-1 SPICE MOSFET models representative of 5μm devices were used wherever individual MOSFETs were used in the design. Finally, the power dissipation during the conversion period was also estimated. The supply voltage for the ADC is 5V and the clock frequency is 500KHz

Mature cystic teratoma mimicking ectopic pregnancy: a case report

We present a case of mature cystic teratoma resembling ectopic pregnancy in a patient with positive serum beta-hCG and an adnexal mass. A 30-year-old woman who was experiencing pelvic pain and vaginal bleeding was sent to the emergency room. An ultrasound revealed a complex right adnexal mass measuring 63×42 mm and the absence of an intrauterine gestational sac. Based on these findings, ectopic pregnancy was suspected; nevertheless, a subsequent magnetic resonance imaging (MRI) was planned, which suggested mature cystic teratoma. On a laparoscopy, later findings were verified. Cyst removal was the patient's treatment. Despite the possibility of an ectopic pregnancy being indicated by the existence of an adnexal mass without an intrauterine gestational sac and a positive beta-hCG level, a mature cystic teratoma should be considered as a differential diagnosis.

Candiduria: its characterization, antifungal susceptibility pattern and biofilm formation

Background: Candida are the fourth most common species causing urinary tract infections. The last two decades has shown rapid increase in Candida associated UTI along with change in its distribution. The indiscriminate use of antifungal drugs, especially azole group have contributed in emergence of resistant strains of Candida. Biofilm producing property of Candida also contributes to antifungal resistance. Aims and objectives was to detect the occurrence of Candida as causative agent of UTI and a potent bio film producer. The susceptibility of Candida to antifungal drugs and their correlation with the production of bio film and presence of Foleys catheter was also determined.Methods: A total of 4192 urine specimens were analysed. Candida species isolated from urine samples were characterized using CHROM agar, sugar assimilation tests and micro morphology on corn meal agar. The antifungal susceptibility testing was performed by modified disc diffusion method on MHA with two drugs; fluconazole 25µg, and voriconazole 1µg discs. The biofilm production capability was tested according to the protocol proposed by Branchini et al.Results: Out of 113 Candida species isolated, 16.8% were Candida albicans as compared to 83.2% non albicans, with Candida tropicalis as the most common species. Antimicrobial sensitivity by modified Kirby Bauer disc diffusion method showed 74.3 % of Candida isolates to be fluconazole sensitive while sensitivity to voriconazole was 100%. 60.2% of Candida were biofilm producers out of which 48.5 % were from urine samples of catheterized patients. Similarly, 26.4 % of fluconazole resistant strains were also biofilm producers.Conclusions: The increased incidence of Non albicans candiduria which are also biofilm producers and resistant to commonly used drug fluconazole is a matter of concern. Therefore, the species identification of Candida isolates along with their antifungal susceptibility pattern should be routinely performed to help the clinicians in better treating the patients with candiduria

Seismic Data Conditioning for Quantitative Interpretation of Unconventional Reservoirs

Shale resource plays are fairly new to the petroleum industry, but they have reinvigorated oil and gas production in North America. Brittleness and TOC are the two most important parameters for shale resource characterization. Ideally, of the multilinear and non-linear regression can be used to correlate TOC and brittleness measured on core to well logs forming a proxy for TOC and brittleness with in the seismic survey. In turn seismic attributes correlated to TOC and brittleness predictions from well logs. The success of such integration depends on data quality. In Texas and the mid-continent much of our seismic data have been merged and reprocessed using modern technology. I will expose one pitfall on merged seismic surveys due to offset range variation. Other pitfalls are best addressed by seismic modeling. Legacy seismic data acquired in the mid-continent region have low fold, resulting in a rise to low signal to noise ratio. Such data often exhibit a strong acquisition footprint, which can be caused by the presence of aliased ground roll. Conventional processing techniques cannot suppress such groundroll without damaging the signal. I developed and applied a coherence-based technique to remove highly aliased ground roll present in a survey of North Central Texas Mississippi Lime play. The predicted TOC and brittleness volumes showed a fair correlation with production in the Barnett Shale of Fort Worth Basin. The areas of good production are associated with high brittleness in the vicinity of high TOC