Flow experiments using heated Jet-A fuel and additives were performed to study the effects of treated surfaces on surface deposition. The experimental apparatus was designed to view deposition due to both thermal oxidative and pyrolytic degradation of the fuel. Carbon burnoff and scanning electron microscopy were used to examine the deposits. To understand the effect of fuel temperature on surface deposition, computational fluid dynamics was used to calculate the two-dimensional temperature profile within the tube. Three kinds of experiments were performed. In the first kind, the dissolved O2 consumption of heated fuel is measured on different surface types over a range of temperatures. It is found that use of treated tubes significantly delays oxidation of the fuel. In the second kind, the treated length of tubing is progressively increased which varies the characteristics of the thermal-oxidative deposits formed. In the third type of experiment, pyrolytic surface deposition in either fully treated or untreated tubes is studied. It is found that the treated surface significantly reduced the formation of surface deposits for both thermal oxidative and pyrolytic degradation mechanisms. Moreover, it was found that the chemical reactions resulting in pyrolytic deposition on the untreated surface are more sensitive to pressure level than those causing pyrolytic deposition on the treated surface.

A flowing, single-pass heat exchanger test rig, with a fuel capacity of 189 liters, has been developed to evaluate jet fuel thermal stability. This “Phoenix Rig” is capable of supplying jet fuel to a 2.15 mm i.d. tube at a pressure up to 3.45 MPa, fuel temperature up to 900 K, and a fuel-tube Reynolds number in the range 300–11,000. Using this test rig, fuel thermal stability (carbon deposition rate), dissolved oxygen consumption, and methane production were measured for three baseline jet fuels and three fuels blended with additives. Such measurement were performed under oxygen-saturation or oxygen-starved conditions. Tests with all of the blended fuel samples showed a noticeable improvement in fuel thermal stability. Both block temperature and test duration increased the total carbon deposits in a nonlinear fashion. Interestingly, those fuels that need a higher threshold temperature to force the consumption of oxygen exhibited greater carbon deposits than those that consume oxygen at a lower temperature. These observations suggested a complicated relationship between the formation of carbon deposits and the temperature-driven consumption of oxygen. A simple analysis, based on a bimolecular reaction rate, correctly accounted for the shape of the oxygen consumption curve for various fuels. This analysis yielded estimates of global bulk parameters of oxygen consumption. The test rig yielded quantitative results, which will be very useful in evaluating fuels additives, understanding the chemistry of deposit formation, and eventually developing a global chemistry model.

Prostate cancer (PC) is the second leading cause of cancer related deaths in US men. Androgen deprivation therapy (ADT) improves clinical outcome, but tumors often recur and progress to androgen independent prostate cancer (AIPC) which no longer responds to ADT. The progression to AIPC is due to genetic alterations that allow PC cancer cells to grow in the absence of androgen. Here we performed an insertional mutagenesis screen using a replication-incompetent lentiviral vector (LV) to identify the genes that promote AIPC in an orthotopic mouse model. Androgen sensitive PC cells, LNCaP, were mutagenized with LV and injected into the prostate of male mice. After tumor development, mice were castrated to select for cells that proliferate in the absence of androgen. Proviral integration sites and nearby dysregulated genes were identified in tumors developed in an androgen deficient environment. Using publically available datasets, the expression of these candidate androgen independence genes in human PC tissues were analyzed. A total of 11 promising candidate AIPC genes were identified: GLYATL1, FLNA, OBSCN, STRA13, WHSC1, ARFGAP3, KDM2A, FAM83H, CLDN7, CNOT6 and B3GNT9. Seven out the 11 candidate genes; GLYATL1, OBSCN, STRA13, KDM2A, FAM83H, CNOT6 and B3GNT6, have not been previously implicated in PC. An in vitro clonogenic assay showed that knockdown of KDM2A, FAM83H and GLYATL1 genes significantly inhibited the colony forming ability of LNCaP cells. Additionally, we showed that a combination of four genes, OBSCN, FAM83H, CLDN7 and ARFGAP3 could significantly predicted the recurrence risk in PC patients after prostatectomy (P=5.3×10-5).

Jet fuel is used for cooling in high-performance aircraft. Unfortunately, jet fuel reacts with dissolved O 2 in the presence of heat to form unwanted surface deposits. Computational fluid dynamics that incorporates pseudo-detailed chemical kinetics with a wall reaction is used to simulate the effects of treated and untreated stainless-steel surfaces on the liquid-phase thermal oxidation of jet fuel in both isothermal and nonisothermal heated-tube experiments. A hydroperoxide decomposition reaction is used to represent the surface chemistry. The effects of a treated surface on thermal oxidation were modeled by adjusting the activation energy of the surface reaction. Nonisothermal heated-tube experiments that measure dissolved O 2 are performed here, whereas isothermal flow experiments are performed elsewhere. Simulations of dissolved O 2 consumption in the presence of treated and untreated surfaces, which include the wall reaction, agree reasonably well with the dissolved O 2 measurements.

The effects of low dissolved oxygen concentrations on fuel thermal stability are far from being understood; however, such an understanding is essential for aircraft fuel system design. Experiments were conducted using a flowing system in which the dissolved oxygen level at the entrance of the apparatus is varied. One of the most intriguing results of these experiments is the increase in deposits in heated sections for decreased oxygen consumption. This observation is seemingly contrary to nearly all previous observations concerning the relation between deposit formation and oxygen consumption. For a given system, there appears to be a least favorable dissolved oxygen concentration which produces the maximum amount of deposits. In addition, the deposition mechanisms in heated locations were quite different from those in cooled regions.