1,316 research outputs found

    Marine Transportation for CCS

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    Thesis (S.M. in Transportation)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 115-118).The objective of this report is to determine whether opportunities to use liquefied carbon dioxide carriers as part of a carbon capture and storage system will exist over the next twenty years. Factors that encourage or discourage the use of vessels are discussed. This study concludes that liquefied carbon dioxide carriers can potentially be used in both the near and long term under different sets of circumstances.by Mary-Irene Alexandrakis and Bret S. Smart.S.M.in Transportatio

    Simulations of Weighted Tree Automata

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    Simulations of weighted tree automata (wta) are considered. It is shown how such simulations can be decomposed into simpler functional and dual functional simulations also called forward and backward simulations. In addition, it is shown in several cases (fields, commutative rings, Noetherian semirings, semiring of natural numbers) that all equivalent wta M and N can be joined by a finite chain of simulations. More precisely, in all mentioned cases there exists a single wta that simulates both M and N. Those results immediately yield decidability of equivalence provided that the semiring is finitely (and effectively) presented.Comment: 17 pages, 2 figure

    Medical Anthropology: The Development of the Field

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    Foreign Investment in U.S. Airlines: Restrictive Law is Ripe for Change

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    Systemic levels of interleukin-6 and matrix metalloproteinase-9 in patients with multiple myeloma may be useful as prognostic indexes of bone disease

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    Multiple myeloma is characterized by accelerated production of the proteolytic enzyme matrix metalloproteinase (MMP)-9. We hypothesized that myeloma- produced MMP-9 may influence the rate of bone turnover in a paracrine manner. Thus, we examined the correlations of MMP-9 levels, disease severity, and bone turnover rate as evaluated by markers of bone formation and resorption. Thirty-seven newly diagnosed multiple myeloma patients (nine of Durie-Salmon stage I, 12 of stage II and 16 of stage III) and 12 age-matched controls were studied. Serum MMP-9 levels were significantly higher at stage II compared to stage I (188.78 91.27 vs. 59.25 33.09 ng/mL, p-0.004). Additionally, free urine pyridinolines (F-Pyd), free urine deoxy-pyridinolines (F-Dpd) and urine N-telopeptide fragment (NTx) were elevated, their level correlating with disease stage (p-0.001, p-0.03, p-0.001, respectively), as were bone marrow infiltration and serum interleukin- 6 (IL-6) levels (p-0.0001, p-0.01, respectively). MMP-9 levels were lower in patients compared with controls (p-0.001), whereas IL-6 and bone resorption marker levels were higher in patients than in controls (p-0.001 in all cases). Significant correlation was found between infiltration, MMP-9, free urine pyd, free urine dpd and NTx for each stage of the disease (p-0.03, p-0.003, p-0.002, p-0.003 and p-0.001, respectively). Levels of MMP-9 and of IL-6 in multiple myeloma correlate well with bone turnover rate and may be useful in disease evaluation

    Anemia in Heart Failure Patients

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    Heart failure is a very common disease, with severe morbidity and mortality, and a frequent reason of hospitalization. Anemia and a concurrent renal impairment are two major risk factors contributing to the severity of the outcome and consist of the cardio renal anemia syndrome. Anemia in heart failure is complex and multifactorial. Hemodilution, absolute or functional iron deficiency, activation of the inflammatory cascade, and impaired erythropoietin production and activity are some pathophysiological mechanisms involved in anemia of the heart failure. Furthermore other concomitant causes of anemia, such as myelodysplastic syndrome and chemotherapy, may worsen the outcome. Based on the pathophysiology of cardiac anemia, there are several therapeutic options that may improve hemoglobin levels, tissues' oxygenation, and probably the outcome. These include administration of iron, erythropoiesis-stimulating agents, and blood transfusions but still the evidence provided for their use remains limited

    Stresses around neighbouring elliptical holes in flat plates.

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    Thesis. 1976. M.S.--Massachusetts Institute of Technology. Dept. of Ocean Engineering.Microfiche copy available in Archives and Engineering.Includes bibliographical references.M.S

    Macromolecule Transport in Tumours

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    The delivery of immunoreactive macromolecules to tumour cells in solid, heterogeneously perfused tumours is a major problem in the effectiveness of immunotherapy. To help optimize the new experimental treatment method, a published mathematical model of macromolecule transport (Baxter & Jain 1989,1990,199la) was appraised and verified experimentally. Computational and analytical tools were developed to predict the interstitial plasma fluid pressure and velocity distributions in well perfused spherical tumours. Their published analytical solutions of the formulation were found to have some errors and were corrected in this work. To check the validity of the formulation, a series of animal experiments was performed to quantify the total vascular volume, and plasma fluid extravasation rate in SKOV3ipl human ovarian tumour xenografts in nude mice. The results compared well with the theoretically predicted total plasma fluid extravasation rate. Computer codes were also developed to predict the spatial and temporal distributions of intact IgG and its F(ab')₂ and Fab/Fab' fragments in well perfused spherical tumours using the formulation proposed by Baxter & Jain (1989,1990,1991a). The cases of non-binding and binding macromolecules were treated separately. The codes for both the interstitial pressure and macromolecule distributions were written to include a radially variable vessel surface area for transcapillary exchange per unit volume of tumour tissue (SN). The sensitivity of the overall tumour perfusion to variation of (a) the macromolecule m.w., binding affinity, and metabolism, (b) SN, tumour radius, and (c) microvascular permeability were investigated. Comparison of the theoretical predictions with available experimental data leads to the realization of a number of shortcomings in the previously proposed formulations. Finally, a computational method for deriving the effective spherically symmetric spatial distributions for the vascular volume density, and SN from tumour serial sections was developed. This bridges the gap between the actual topology of vascular distributions in tumours and the format of current formulations.ThesisMaster of Science (MS

    On the existence and evaluation of Stokes phenomena in fluid mechanics

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    A singularly perturbed, high order KdV-type model, which describes localized travelling waves ('solitons') is being considered. We focus on the Inner solution, and detect Stokes phenomena that are crucial as to whether we can obtain a suitable solution. We provide a simple proof that the corresponding Stokes constant is non-zero. Also, we evaluate this splitting constant numerically by using two methods that are induced by the underlying theory
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