The effects of the addition of n-butanol on the formation of hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) of n-heptane combustions were investigated using a micro flow reactor (MFR) with a controlled temperature profile. The concentrations of small and large hydrocarbons, as well as PAHs were measured at a maximum wall temperature of 1,100 K and atmospheric pressure. The values obtained from several mechanisms were compared to the measurement values at equivalence ratios of 2.0–5.0. The CRECK mechanism was in fair agreement with the measurements. The computational results confirmed that the concentration of the PAHs and soot precursors' decreased, while that of CO and CO2 increased due to the addition of butanol. These trends were also shown by the measurement values. The reaction path and rate of production analyzes were carried out to identify the major reactions contributing toward species concentrations.
A 62 years-old male visited us to undergo further detailed examination following the positive fecal occult blood test. Type-Ip lesion revealing a fine villous structure at the top was discerned endoscopically which resulted in the diagnosis of serrated adenoma. EMR (endoscopic mucosal resection) was well indicated. At the second endoscopic examination for EMR, however, in the lower part of the lesion, an irregularly-shaped concavity, endoscopically rigid, revealing the loss of villous structure was present, leading to the suspect diagnosis of sm2 invasive cancer in adenoma. Accordingly, the treatment was switched from EMR to surgical operation. Furthermore, through endoscopy just before the surgical operation, the concavity deepened along with the whitish coating, which was strongly indicative of sm2 cancer. Laparoscopic assisted partial resection was carried out in the ascending colon. Pathologically diagnosed as moderately differentiated adenocarcinoma in serrated adenoma, sm2, ly2, v2, n0. The malignant potential of serrated adenoma is considered to be almost equal to that of ordinary adenoma. Taking into consideration that the larger the diameter of a lesion becomes, the greater the malignant incidence grows, and that there actually exists sm invasive cancer originating from serrated adenoma requiring surgical operation, we are expected to scrutinize the lesion of serrated adenoma through endoscopy as to whether it is cancerous or not.
Ignition and combustion characteristics of stoichiometric Dimethyl ether (DME)/Air mixture are investigated by using a micro flowreactor with controlled temperature profile which is smoothly increasing from the room temperature to the ignition temperature. Special attention is paid to the multi-stage oxidation in low temperature oxidation. Various flame responses were observed by changing incoming mixture velocity. Stable double weak luminous zones at low velocity region are observed. One-dimensional computation with detail chemistry showed stationary three-stage oxidation defined by the triple peaks in the heat release rate profile at relevant low velocity region. To interpret discrepancy between experimental double weak flames and computational triple flames, gas sampling was conducted for obtaining major species distributions in the flowreactor. The results indicated that low-temperature oxidation occurs in the upstream side of the experimental first luminous zone. Thus, three-stage oxidation can be indi9ated as a stationary phenomon experimentally and computationally.
