167 research outputs found
INC892792 Supplemental Material - Supplemental material for The effect of timing of initiation of renal replacement therapy on mortality: A retrospective case–control study
No full textSupplemental material, INC892792 Supplemental Material for The effect of timing of initiation of renal replacement therapy on mortality: A retrospective case–control study by Milo Engoren, Michael D Maile, Michael Heung, James M Blum, Ross Blank, Lena M Napolitano, Pauline K Park, Krishnan Raghavendran, Elizabeth S Jewell and Craig Meldrum in Journal of the Intensive Care Society</p
Active skin for turbulent drag reduction
No full textDue to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references (leaves 107-111).Issued also on microfiche from Lange Micrographics.Drag reduction for aerial vehicles has a range of positive ramifications: reduced fuel consumption with the associated economic and environmental consequences, larger flight range and endurance and higher achievable flight speeds. This work capitalizes on recent advances in active turbulent drag reduction and active material based actuation to develop an active or "smart" skin for turbulent drag reduction in realistic flight conditions. The skin operation principle is based on computational evidence that spanwise traveling waves of the right amplitude, wavelength and frequency can result in significant turbulent drag reduction. Such traveling waves can be induced in the smart skin via active-material actuation. The flow control technique pursued is "micro" in the sense that only micro-scale wave amplitudes (order of 30[]m) and energy inputs are sufficient to produce significant benefits. Two actuation principles are proposed and analyzed and different skin designs based on these two actuation principles are discussed. The feasibility of the different actuation possibilities (such as Shape Memory Alloys and Piezoelectric material based actuators) and relative merits of different skin designs are discussed. Multi-step dynamic analyses are performed to study the response of the skin at various actuation frequencies
Urinary Bladder Xanthoma – Is Immunohistochemistry Necessary?
No full textAbstractUrinary Bladder Xanthomas (UBX) are non-neoplastic reactive tumor like process. Isolated UBX is rare with only around 15 cases reported (Yu, Patel, & Bonert, 2015). UBX are reported in older patients who present with non specific symptoms like UTI or hematuria. Patients often have associated lipid anomalies. UBX have been vaguely described as yellowish white plaques or patches. Also, recent reports have stressed on the role of Immunohistochemistry in the diagnosis (Al-Daraji, Varghese, & Husain, 2007; Vimal, Masih, Manipadam, & Chacko, 2012). The objective of this report is to provide a cystoscopic view of the tumor which will enable easier identification and also to debate on the role of IHC in diagnosis
Study of droplet dynamics in transcritical environments
No full textEfficient combustion processes are indispensable in limiting the temperature increase to 1.5 deg C as set by Intergovernmental Panel on Climate Change (IPCC) before 2030 to curtail the effects of global warming. As for the emissions, the main task lies in controlling the air-fuel ratio in the lean regime as to control the emissions of NOx since they reach maximum discharge at the stoichiometric ratio whereas improper mixing can lead to an increase in CO emissions. Thus, the air and fuel interactions need to be studied to achieve control over emissions. To that end, good computational models are necessary to supplement the design process to control both the emissions and combustion instabilities. The latter can severely damage the combustion chamber. Therefore, the proper modeling of the fuel-air interfaces in high-pressures is pivotal as they differ significantly from the low-pressure injection. Various numerical droplet evaporation models are studied in trans/supercritical environments, the fluid is called supercritical when it's above the critical states whereas it is called transcritical when it passes the critical state. As for the droplets, two components were selected namely n-heptane and n-dodecane. The former for 0-D and 1-D models and the latter for 3-D models, the cases were dictated by the availability of experimental works. As for the 0-D and 1-D models, various correlations based on the Nusselt and Sherwood numbers were utilized. The Prandtl number and other non-dimensional numbers were computed by thermophysical property models based on the 1/3 rd rule rather than fixed values. In comparison, the developed 0-D and 1-D models conform to the experimental results and other computational studies ranging from perfect-gas to real-gas against the experimental work available in the literature. It is hypothesized that the differences in the computation of the latent heat of vaporization are more pronounced in the accuracy of the lifetime of the droplet rather than the density of the components. In 3-D models, the liquid-vapor interface is modeled by level-set and phase-field methods. Thermodynamic closure is achieved by the Peng- Robinson equation of state. Prandtl number assumption model is invoked for the computation of the liquid thermal conductivity, Chung model for the calculation of viscosity of mixtures, and Firoozabadi model for the Maxwell-Stefan diffusion coefficient. A basic model is used for the computation of surface tension coefficient for the phase-field 3-D models. A qualitative agreement was observed between the 3D model under this study, numerical work, and the experimental campaign of microscopic droplets for all the three vaporization regimes namely classical, translational and diffusive mixing. All the models yielded olive-shaped droplets. Effects of mesh resolution on the phase-field quantities were studied and contrasted with the same mesh size for the level set method in a 2-D configuration. Recommendations include better surface tension models, thermal conductivity for gaseous mixtures, the inclusion of PC-SAFT equation of state, cross-diffusion terms, and high mesh resolution of the O(-7) m in the droplet region coupled with adaptive meshing based on the gradient of the phase-field parameter.Aerospace Engineerin
Chlorate Reduction in Water using Advanced Reduction Processes
No full textChlorate is one of the disinfection byproducts when chlorine/chlorine dioxide is used as the primary disinfectant. Excess amounts of chlorate in drinking water above permissible limits are toxic. This study investigated chlorate removal from water by photochemical degradation using advanced reduction processes (ARP). This new class of treatment processes combines a reducing agent and an activation method to generate reducing radicals that can efficiently destroy persistent oxidized contaminants. The effectiveness of combinations of four reducing agents (sulfite, dithionite, sulfide, and ferrous iron) and three UV light sources (UV-L, UV-M, and UV-B) were evaluated for chlorate removal. Dithionite irradiated by broad-band UVB lamp having the output between 280 nm and 320 nm with peak energy at 312 nm (UV-B) showed the highest chlorate removal. In pursuit of finding the optimum ARP conditions, the process variables including pH, reducing agent dose, initial chlorate concentration and light intensity were investigated. Dithionite/UV-B ARP was effective at weakly acidic conditions less than pH 5, and chlorate removal occurred in two steps. The first was an initial rapid decrease in chlorate concentration that occurred before initiating UV irradiation and was attributed to reaction with dithionite decomposition products. Bisulfite or metabisulfite in equilibrium with bisulfite are believed to be the decomposition products responsible for chlorate reduction. The second step was a slow decrease during UV irradiation that is caused by radicals produced by photolysis of the products of dithionite decomposition. The major product of chlorate destruction was chloride, with negligible amounts of chlorite produced
Impact of DSCSA on United States pharmaceutical industry under decentralized information flow
No full textThesis: M. Eng. in Supply Chain Management, Massachusetts Institute of Technology, Supply Chain Management Program, 2017.Cataloged from PDF version of thesis.Includes bibliographical references (pages 46-47).Drug counterfeiting is one of the major issues in the pharmaceutical industry across the world. These products could cause damages from ineffective treatments to death of patients. In order to fight against counterfeit drugs, the US government introduced Drug Supply Chain Security Act (DSCSA) mandating that all prescription drugs should be serialized. In addition, it mandates all pharmaceutical companies in the U.S. to provide tracking documents in response to a tracing request from FDA. While the act aims to improve drug security across the pharmaceutical industry, it poses a huge impact across the supply chain on both physical flow and information flow. This research evaluates the supply chain impact at an industry level. In this thesis, we evaluate the supply chain impact of Matryoshka model and Unit level model supported by a decentralized information flow. The thesis then evaluates the supply chain impact from three aspects, operational cost, IT infrastructure cost and capital investment. We reference Nabiyeva and Wu's research on centralized information flow model to conduct an exhaustive supply chain impact evaluation across the centralized model and the decentralized model. We conclude that among all these scenarios, unit level model under centralized information flow design bears the highest cost as it requires higher IT investment. On the other hand, the matryoshka model under decentralized information flow has a least supply chain impact from the cost perspective with low IT investment.by Meng Ying Chang and Raghavendran Mohan.M. Eng. in Supply Chain Managemen
Improved validation of IDP ensembles by one-bond Cα-Hα scalar couplings.
No full textIntrinsically disordered proteins (IDPs) are best described by ensembles of conformations and a variety of approaches have been developed to determine IDP ensembles. Because of the large number of conformations, however, cross-validation of the determined ensembles by independent experimental data is crucial. The (1)JCalphaHalpha coupling constant is particularly suited for cross-validation, because it has a large magnitude and mostly depends on the often less accessible dihedral angle psi. Here, we reinvestigated the connection between (1)JCalphaHalpha values and protein backbone dihedral angles. We show that accurate amino-acid specific random coil values of the (1)JCαHα coupling constant, in combination with a reparameterized empirical Karplus-type equation, allow for reliable cross-validation of molecular ensembles of IDPs
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