METHANOL STEAM REFORMING FOR HYDROGEN PRODUCTION IN MICROCHANNEL REACTORS

Many attempts have been made to improve heat transfer for thermally integrated microchannel reforming reactors. However, the mechanisms for the effects of design factors on heat transfer characteristics are still not fully understood. This study relates to a thermochemical process for producing hydrogen by the catalytic endothermic reaction of methanol with steam in a thermally integrated microchannel reforming reactor. Computational fluid dynamics simulations are conducted to better understand the consumption, generation, and exchange of thermal energy between endothermic and exothermic processes in the reactor. The effects of wall heat conduction properties and channel dimensions on heat transfer characteristics and reactor performance are investigated. Thermodynamic analysis is performed based on specific enthalpy to better understand the evolution of thermal energy in the reactor. The results indicate that the thermal conductivity of the channel walls is fundamentally important. Materials with high thermal conductivity are preferred for the channel walls. Thermally conductive ceramics and metals are well-suited. Wall materials with poor heat conduction properties degrade the reactor performance. Reaction heat flux profiles are considerably affected by channel dimensions. The peak reaction heat flux increases with the channel dimensions while maintaining the flow rates. The change in specific enthalpy is positive for the exothermic reaction and negative for the endothermic reaction. The change in specific sensible enthalpy is always positive. Design recommendations are made to improve thermal performance for the reactor

Aggregation and Dendrimer Mediated Secondary Binding towards Folate Binding Protein & Fatigue Failure Mechanism of Anterior Cruciate Ligament Fracture

Drug conjugation gives many advantages such as improved targeting, solubility and retention. How conjugated drugs interact with proteins is a key question to answer in targeted drug delivery. This not only includes the interaction with the target protein, but also includes the proteins that the drug carrier may encounter during drug trafficking. Folic acid (FA) is of wide interest as a targeting agent. It provides targeting effect towards the folate receptor (FR), a commonly overexpressed protein in breast cancer and ovarian cancer. Chapter one focused on developing a conjugated tighter binder towards the soluble form of folate receptor, folate binding protein (FBP). This strategy employed a PAMAM dendrimer conjugated folic acid; the dissociation constant was improved from 20 nM of free folic acid to 2 nM of the dendrimer conjugated folic acid. The folate binding protein is a minor serum protein and is known to aggregate upon binding to folic acid. This aggregation could pose risk factors for drug delivery vectors such as the folic acid conjugated iron oxide nanoparticles. In chapter two, folate binding protein was shown to aggregate to large iron oxide nanoparticles that are conjugated to folic acid, triggering the agglomeration cascade that could drastically change the size of these nanoparticles. Chapter three addresses a question that is important to sport medicine: what leads to non-contact anterior cruciate ligament (ACL) failure? Our hypothesis was that before the ACL fracture, microdamage would have already been created by jumping and landing activities. In this chapter, paired cadaveric knees were collected and one of the pair was mechanically tested under submaximal loading to see to what extent the microdamage would be created. A hierarchical damage ranging from nanometer level to micrometer level were detected using various methods including atomic force microscopy (AFM), nanoIR, second harmonic generation (SHG) and confocal microscopy. These microdamages exhibits patterns that resemble the fractured ACL seen in the clinical patients.PHDChemistryUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/144055/1/junjchen_1.pd

Review On the Combustion Characteristics of Polymer and Hybrid Fuels for Hybrid Propulsion Systems

Hybrid Propulsion is an attractive alternative to conventional liquid and solid rocket engines. This is an active area of research and technological developments. The potential wide application of the hybrid engines opens the possibility for safer and more flexible space vehicle launching and manoeuvring. The fundamental combustion issues related to further development of hybrid rockets are discussed in the present paper. The emphasis is made on the properties of the potential polymeric fuels and their modification. The fundamentals of polymeric fuel combustion and the flammability Characteristics are discussed