Recursos de colección

DSpace at MIT (104.280 recursos)

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Chemical Engineering - Ph.D. / Sc.D.

Mostrando recursos 1 - 20 de 1.076

  1. The effect of solute on the liquid film resistance in gas absorption

    Hutchinson, Margaret H
    by Margaret H. Hutchinson.

  2. Heat and mass transfer from particles suspended in a stirred tank,

    Hales, Hugh Bradley, 1940-
    by Hugh B. Hales.

  3. Robust simulation and optimization methods for natural gas liquefaction processes

    Watson, Harry Alexander James
    Natural gas is one of the world's leading sources of fuel in terms of both global production and consumption. The abundance of reserves that may be developed at relatively low cost, paired with escalating societal and regulatory pressures to harness low carbon fuels, situates natural gas in a position of growing importance to the global energy landscape. However, the nonuniform distribution of readily-developable natural gas sources around the world necessitates the existence of an international gas market that can serve those regions without reasonable access to reserves. International transmission of natural gas via pipeline is generally cost-prohibitive beyond around two...

  4. Optimal control of dynamical systems with time-invariant probabilistic parametric uncertainties

    Shen, Dongying Erin
    The importance of taking model uncertainties into account during controller design is well established. Although this theory is well developed and quite mature, the worst-case uncertainty descriptions assumed in robust control formulations are incompatible with the uncertainty descriptions generated by commercial model identification software that produces time-invariant parameter uncertainties typically in the form of probability distribution functions. This doctoral thesis derives rigorous theory and algorithms for the optimal control of dynamical systems with time-invariant probabilistic uncertainties. The main contribution of this thesis is new feedback control design algorithms for linear time-invariant systems with time-invariant probabilistic parametric uncertainties and stochastic noise....

  5. Improving efficacy of therapeutics by enhancing delivery using chemical engineering

    Tam, Hok Hei
    In the past decades, many new and interesting modalities for therapeutics have been discovered, including nucleic acid therapeutics such as siRNA and mRNA. However, one of the limiting challenges in developing these technologies into medicines is delivering the therapeutics to the correct location in the body or in the cell. Furthermore, many older modalities for therapeutics, such as vaccines and chemotherapeutics, could become more efficacious with optimization of delivery. By using chemical engineering principles, we can develop better delivery methods, materials, and formulations to improve the treatment of a wide range of diseases. In this thesis, I report on applications...

  6. Predictive chemical kinetics for auto ignition of fuel blends

    Yee, Nathan W. (Nathan Wa-Wai)
    Predictive chemical kinetics plays an important part in the study of chemical systems by reducing the need for expensive experiments. The size and complexity of modem chemical mechanisms increasingly require the use of automated mechanism generators, such as the Reaction Mechanism Generator (RMG). Use of these automated generators for creating quality chemical mechanisms necessitates accurate reaction rates. Unfortunately, the vast majority of kinetic parameters governing rate constants are not known. The goals of this thesis are the accurate estimation of kinetic parameters and its application to the prediction of auto ignition in fuel blends. At the molecular scale, quantum chemical...

  7. Transport of molecules through and on carbon nanostructures

    Drahushuk, Lee William
    Single-layer graphene membranes and other 2D membranes can realize very high gas permeation fluxes due to their atomic or unit cell thickness. Established modeling approaches for membrane transport consider transport through a finite and continuum thickness, and therefore they do not apply to the emerging field of 2D membranes, motivating the development of new theoretical treatments. In this thesis, I first developed an analytical theory for the transport of gases through single- layer graphene membranes, from the perspective of using pores in the graphene layer as a means for separation. I considered two pathways for the transport. The first being...

  8. Leveraging features of nanoscale particulates for information encoding, quantitative sensing and drug delivery

    Bisso, Paul W. (Paul William)
    It is both uncontroversial and unassailable to assert that small things can often go where big things cannot. It is similarly prosaic to note that at smaller length scales, matter behaves differently than at larger length scales. This thesis exploits these intuitive and simple axioms to yield advances in three independent lines of enquiry: (i) robust and practically accessible encoding of information within microparticles, (ii) rapid, quantitative sensing of hydrophobic colloids and (iii) immunologically-focused drug delivery. Specifically, upconversion nanocrystals are used as the foundation of a novel spatial-spectral patterning motif to produce polymer microparticles with unique, decodable identities. With large...

  9. Effects of gamma-irradiation and additives on the growth of potassium chloride crystals from aqueous solutions.

    Botsaris, G. D
    Massachusetts Institute of Technology. Dept. of Chemical Engineering. Thesis. 1965. Ph.D.

  10. Conformational investigations of a model polyzwitterion and its applications in oil recovery

    Ranka, Mikhil Ajay
    In recent years, nanoparticles have demonstrated immense promise for the development of next generation technologies for subsurface reservoir characterization and oil recovery. Until now however, the scope of such nanoparticles has been limited due to the significant challenge of colloidal stabilization under the extreme salinity and high temperature conditions typical of a reservoir. Previous efforts to address this problem have focused on conventional polyelectrolyte based stabilizers, which unfortunately fail at high ionic strengths due to excessive charge screening. In this thesis, we demonstrate a new approach to stabilization that overcomes this key deficiency, by specifically taking advantage of the excessive...

  11. Controlled release microneedle technologies for the enhanced immunogenicity of subunit vaccines

    Zmolek, Andrew Charles
    The poor efficacy of subunit protein vaccines, which typically consist of a protein antigen and a molecular adjuvant, has recently been improved by completing multiple injections of the vaccine with an exponential dosing profile over time. The hypothesis is that as viruses replicate in a host organism, they shed exponentially increasing quantities of pathogen associated molecular patterns (PAMPs) and viral protein, and replicating this pattern during vaccination allows scientists to better mimic the immune response elicited by an actual infection. Instead of completing multiple injections, a promising alternative is to complete a one-time application of a microneedle device to the...

  12. Microfluidic processes to create structured microparticle arrangements and their applications

    Kim, Jae Jung, Ph. D. Massachusetts Institute of Technology
    Multifunctional polymeric microparticles have shown the great potentials in a variety of fields. While the advance in particle synthesis allows for fine tuning of their physical properties and chemical functionality, particle manipulation is still appealing, but challenging issue in colloidal science. In order to expand the utility of microparticles, many particle manipulation techniques have been developed to arrange large-scale of particles at precise locations. However, current approaches cannot simultaneously fulfill desired capabilities of arrangement: scalability, precision, specificity, and versatility. This thesis explores the ability to synthesize particles with a controllability of characteristics, and development of a new microfluidic platform, porous...

  13. Formation of nanoemulsions and entrapped microdroplets

    Gupta, Ankur, Ph. D. Massachusetts Institute of Technology
    Nanoeinulsions (or nano-scale emulsions) are gaining importance in diverse areas like drug delivery, development of smart food drinks, personal care, advanced material synthesis and pharmaceutics. They possess attractive properties such as high surface area, robust stability and tunable rheology. There are two broad categories of method to prepare nanoemulsions: high energy and low energy methods. The literature lacks a mechanistic understanding of nanoemulsion formation leading to a trial and error approach. In this thesis, we address this issue by providing a rationale to synthesize nanoemulsions for both high energy and low energy methods. Specifically, we develop a new scaling theory...

  14. An integrated approach to understanding the metabolic rewiring of cancer cells

    Keibler, Mark Andrew
    Cancer remains a leading worldwide health problem, and in the U.S., 1 in 3 women and 1 in 2 men are expected to develop it during their lifetimes. While the last several decades have provided tremendous understanding of the genetic mutations and signaling pathways that give rise to oncogenic transformation. However, the field of oncology has only relatively recently begun to appreciate the extent of metabolic rewiring required to sustain the uncontrolled growth of tumors. Cancer metabolism is now an active area of research, and efforts are underway to expand the range of oncology diagnostics and therapeutics through targeting metabolism....

  15. Charge carrier dynamics in lead sulfide quantum dot solids

    Gilmore, Rachel Hoffman
    Quantum dots, also called semiconductor nanocrystals, are an interesting class of materials because their band gap is a function of the quantum dot size. Their optical properties are not determined solely by the atomic composition, but may be engineered. Advances in quantum dot synthesis have enabled control of the ensemble size dispersity and the creation of monodisperse quantum dot ensembles with size variations of less than one atomic layer. Quantum dots have been used in a variety of applications including solar cells, light-emitting diodes, photodetectors, and thermoelectrics. In many of these applications, understanding charge transport in quantum dot solids is...

  16. Certain cohesive and adhesive characteristics of thermoplastic high polymers

    Merrill, Edward W
    by Edward Wilson Merrill.

  17. Multidimensional population balance modeling and optimization of continuous reactive crystallization

    Zhu, Zhilong, Ph. D. Massachusetts Institute of Technology
    Phosphoric acid is the primary ingredient for almost all the phosphorous based fertilizer used in agriculture around the world. During the production of phosphoric acid, phosphate rock is reacted with sulfuric acid producing gypsum as the byproduct that is separated from the phosphoric acid by filtration. The efficiency of filtration depends strongly on the crystal size distribution (CSD) and shape. Undesired gypsum CSD and shape not only prolong the filtration and bottleneck the plant's overall production, but also decrease the phosphate recovery from the wet cake. To optimize the process, a first-principle process model is developed for the reactor-crystallizer to...

  18. Study of the differential compartmentation and functions of hexokinase isoforms and implications for cancer metabolism

    Zhang, Zhe, Ph. D. Massachusetts Institute of Technology
    Selectivity is a very important consideration when designing cancer treatment. Therefore, targeting cancer-specific isoforms of key metabolic enzymes is a very promising strategy. Elevated glucose consumption and lactate secretion under aerobic conditions is a hallmark of many cancer cells. One of the major contributors to this highly glycolytic phenotype is hexokinase 2 isoform (HK2), which is significantly overexpressed in many tumors but not in normal adult tissue. Several small molecule inhibitors targeting HK have exhibited promising anticancer activity. However, these small molecule inhibitors cannot differentiate between HK isoforms, leading to severe side effects. Elucidating the differences between HK isoforms can...

  19. Targeting immunosuppression in the tumor microenvironment and protein-based antagonism of oncogenic K-Ras

    Kauke, Monique Jacqueline
    Cancer is routinely treated with surgery, chemotherapy, and radiotherapy, but in recent decades, two new modes of treatment have emerged, targeted therapy and immunotherapy. Targeted therapies exploit differences between cancerous and healthy cells, targeting the proteins and pathways that exclusively drive cancer cell growth, while immunotherapies harness the body's immune system to destroy cancer cells. With these new treatment strategies, tumor regression and complete remission of disease have become attainable for a larger subset of patients. Nevertheless, the fight against cancer continues to be met with significant challenges, including development of resistance to targeted therapies and immunosuppressive factors that cripple...

  20. Catalytic upgrading of biomass through the hydrodeoxygenation (HDO) of bio-oil derived model compounds

    Shetty, Manish
    Lignocellulosic biomass is an attractive renewable source for fuels and chemicals. Of the many conversion alternatives, catalytic fast pyrolysis has emerged as an attractive technology to convert biomass into fuel additives and value-added chemicals. Current pyrolysis oils or bio-oils are incompatible with refinery streams due to their high acid, water, and water content. The key roadblock in its commercial exploitation is development of catalytic platforms for selective deoxygenation along with minimum hydrogen consumption and carbon loss. Current catalytic solutions including zeolites, and conventional hydrotreating catalysts employ high hydrogen pressures, leading to aromatic ring hydrogenation, and hydrogen consumption. This thesis focusses...

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