A finite element method for geometrically nonlinear large displacement problems in thin, elastic plates and shells

A finite element method is presented for geometrically nonlinear large displacement problems in thin, elastic plates and shells of arbitrary shape and boundary conditions subject to externally applied concentrated or distributed loading. The initially flat plate or curved shell is idealized as an assemblage of flat, triangular plate, finite elements representing both membrane and flexural properties. The \u27geometrical\u27 stiffness of the resulting eighteen degree-of-freedom triangular element is derived from a purely geometrical standpoint. This stiffness in conjunction with the standard small displacement \u27elastic\u27 stiffness is used in the linear-incremental approach to obtain numerical solutions to the large displacement problem. Only stable equilibrium configurations are considered and engineering strains are assumed to remain small. Four examples are presented to demonstrate the validity and versatility of the method and to point out its deficiencies --Abstract, page ii

Design and fabrication of a full-size landing impact test model of the Mars legged lander configuration Master agreement, task order three

Design and fabrication of full size landing impact test model of Mars legged lander configuratio

Percutaneous coil embolization of postcatheterization arterial femoral pseudoaneurysms

AbstractStudy Design: This study was a prospective monocentric study to assess the safety and effectiveness of percutaneous embolization with coils of postcatheterization femoral pseudoaneurysm (PCFP). Patients and Methods: Seventeen PCFPs of 32-mm mean diameter in 16 patients were embolized while anticoagulant or antiplatelet therapy was maintained. Ultrasound scan-guided compression repair failed at least one time in 13 cases and was contraindicated in the four remaining cases. With ultrasound-Doppler scan guidance, the PCFPs were percutaneously punctured with a 16-gauge intravenous catheter. An angiogram was performed through the catheter to ensure its location within the sac. Stainless steel spring coils with synthetic fibers were introduced within the PCFP with fluoroscopic control. Successful thrombosis was checked with ultrasound-Doppler scan and was repeated at days 1, 30, and 180 when possible. Results: All PCFPs of 32-mm mean diameter were successfully treated with two to nine coils. After embolization, gentle additional compression was necessary for complete occlusion, with a mean duration of 6.3 minutes (range, 0 to 15 minutes), except in one case with treatment with abciximab in which it was 45 minutes. All procedures were uneventful and painless. The mean follow-up period was 9.5 months (range, 1 to 21 months). Two recurrences (11.7%) were observed, and one was successfully treated with a second embolization. Conclusion: Percutaneous embolization with coils appears to be a safe and effective method for treatment of PCFP. It may be performed in patients undergoing anticoagulant or antiplatelet therapy and must be attempted when ultrasound scan-guided compression repair has failed or is contraindicated. (J Vasc Surg 2002;36:127-31.

Analyses and limited evaluation of payload and legged landing system structures for the survivable soft landing of instrument payloads

Two computer programs for investigation of wide variety of legged planetary landing gear configuration

Benign cervical multi-nodular goiter presenting with acute airway obstruction: a case report

<p>Abstract</p> <p>Introduction</p> <p>Benign cervical goiters rarely cause acute airway obstruction.</p> <p>Case presentation</p> <p>We report the case of a 64-year-old woman of African descent who presented with acute shortness of breath. She required immediate intubation and later a total thyroidectomy for a benign cervical multi-nodular goiter with no retrosternal tracheal compression.</p> <p>Conclusion</p> <p>Benign multi-nodular goiters are commonly left untreated once euthyroid. Peak inspiratory flow rates should be measured via spirometry in all goiters to assess the degree of tracheal compression. Once tracheal compression is identified, an elective total thyroidectomy should be performed to prevent morbidity and mortality from acute airway obstruction.</p

Predictors of the need for an extracervical approach to intrathoracic goitre

Background: Sternotomy and lateral thoracotomy are required infrequently to remove an intrathoracic goitre (ITG). As few studies have explored the need for an extracervical approach (ECA), the aim of this study was to examine this in a large cohort of patients. Methods: A prospective database of all patients who had surgery for ITG between 2004 and 2016 was interrogated. Patient demographics, preoperative characteristics and type of operation were analysed to identify factors associated with an ECA. Results: Of 237 patients who had surgery for ITG, 29 (12·2 per cent) required an ECA. ITGs below the aortic arch (odds ratio (OR) 10·84; P = 0·004), those with an iceberg shape (OR 59·30; P < 0·001) and revisional surgery (OR 4·83; P = 0·022) were significant preoperative predictors of an ECA. Conclusion: The extent of intrathoracic extension in relation to the aortic arch, iceberg goitre shape and revisional surgery were independent risk factors for ECA. Careful preoperative assessment should take these factors into consideration when determining the optimal surgical approach to ITG

Percutaneous Endovascular Treatment of Innominate Artery Lesions

AbstractPurposeTo assess primary success and safety of percutaneous transluminal angioplasty and/or stenting of innominate artery lesions and to compare its 30-day stroke/mortality level with the literature data.MethodsA total of 72 patients (77 stenoses, five recurrent, 58 symptomatic and 39 female) with seven innominate vessel occlusions, nine subocclusive lesions and 61 significant (>60%) stenoses of innominate artery treated between 2000 and 2009 were retrospectively reviewed. With the exception of seven, all procedures were performed using a transfemoral approach. A stent was implanted in 49 (63.6%) cases. Follow-up included neurological examination, carotid duplex scan and office/telephone interview.ResultsPrimary technical success was 93.5% (72/77). There was neither periprocedural (<48h) death, nor major neurological complication. Minor periprocedural neurological complications consisted of 2/72 (2.6%) ipsilateral TIAs. Access site complications included 4 (5.2%) access site bleedings. Follow-up was achieved in 65/72 (90.3%) of all patients and 68 (88.3%) of all procedures for a mean of 42.3 months and revealed neither major neurological complication, nor additional TIA.The cumulative primary patency rate was 100% at 12 months, 98±1.6% at 24 months, and 69.9±8.5% at 96 months. The cumulative secondary patency rate was 100% at 12 and at 24 months, and 81.5±7.7% at 96 months. Log-rank test showed no significant difference (p=0.79) in primary cumulative patencies between PTA alone (n=28) or PTA/stent (n=49).ConclusionTransfemoral PTA with or without stent appears to be a safe treatment option for innominate artery lesions

Uninfected Para-Anastomotic Aneurysms after Infrarenal Aortic Grafting

Purpose: This single-institution retrospective review examines the management of uninfected para-anastomotic aneurysms of the abdominal aorta (PAAA), developed after infrarenal grafting. Materials and Methods: From October 1979 to November 2005, 31 PAAA were observed in our Department. Twenty-six uninfected PAAA of degenerative etiology, including 24 false and 2 true aneurysms, were candidates for intervention and retrospectively included in our database for management and outcome evaluation. Six (23%) patients were treated as emergencies. Surgery included tube graft interposition (n = 12), new reconstruction (n = 8), and graft removal with extra-anatomic bypass (n = 3). Endovascular management (n = 3) consisted of free-flow tube endografts. Results: The mortality rate among the elective and emergency cases was 5% and 66.6%, respectively (p = 0.005). The morbidity rate in elective cases was 57.8%, whereas 75% in emergency cases (p = 0.99). The survival rate during the follow-up was significantly higher for elective cases than for emergency cases. Conclusion: Uninfected PAAA is a late complication of aortic grafting, tends to evolve silently and is difficult to diagnose. The prevalence is underestimated and increases with time since surgery. The mortality rate is higher among patients treated as an emergency than among patients who undergo elective surgery, therefore, elective treatment and aggressive management in the case of pseudoaneurysm are the keys to obtain a good outcome. Endovascular treatment could reduce mortality. Patients who undergo infrarenal aortic grafting require life-long surveillance after surgery

Women in the church (Middle Ages)

Chattanooga State undergraduate researchers present current research projects: This project focuses on the women in the church during the Middle Ages, what their role and purpose was to the Catholic Church. During this period of time, the main strategy of a woman becoming a saint was asceticism. Asceticism worked in a way of martyrdom through the practices of fasting and chastity. During this time women were seen as inferior to men, but in the eyes of the church the way they could make up for it was living an ascetic life. A big part of this is to remain a virgin, metaphorically the church’s bride. The rise of these female saints’ lives continued to grow in the church and through society, setting a standard for sainthood. In England, this way of life also gave a rise to convents so that these women could live together and embrace the ascetic lifestyle. The women who became saints were not granted sainthood until after their death. During the middle ages there was a rise of female, virgin martyrs. There is controversy as to why there was the rise of virgin martyrs. One side mentions the concern of how often this type of saint comes about, a man trying to seduce a young, untouched woman, being subjected to violence specifically from men ending with the woman’s death. The concern was that it could be said that there was some type of justification of treatment towards women if they ended becoming saints. The other side says that these women became saints because they were strong women, who did not bow down or give up their beliefs even if it meant they would die in the end. Another aspect that impacted women in society during that time was the Virgin Mary, giving into the idea that women did not have to marry to confirm her identity. Focusing on a couple of saints during this time is Saint Hilda of Whitby. Her life started out by being raised in the Catholic faith. She was considered to be highly educated for a female during that time. Because of her education and experience, she was sought out by any and all types of people. She lived in and took care of the large estate of Whitby. During that time that area there was a vote to determine if Catholicism would be allowed in Britain. Even though the vote ended in against the church, Hilda stuck by the church’s side and encouraged people to seek Catholicism. Julian of Norwich was a Christian writer during the middle ages around mid to late 14th century. Her focus on the church was mainly about her interpretation of the Holy Trinity, how God can play the role of being a divine being and also being human. She spent her life without being married due to her not needing that role to be played for herself. She devoted her life to prayer and lived in a cell that was a part of the St. Julian Church in Norwich

Effects of Dietary Inorganic Acids, Their Salts, and Cation - Anion Ratios on Growth, Mineral and Nitrogen Metabolism in the Rat and Chick

98 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1966.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD