Effect of low load combustion and emissions on fuel dilution in lubricating oil and deposit formation of DI diesel engines fueled by straight rapeseed oil

The objective of this study is to apply neat biomass fuel to a DI diesel engine and investigate the effect of in-cylinder gas flow and combustion on the deposit formation and the fuel dilution in lubricating oil. The study focuses on the low load combustion and emissions considering that low load exhaust contain much unburned fuels and the unburned fuels are the source of the deposit formation and the fuel dilution. Piston configuration and swirl velocity were altered in the engine test. The engine was fueled by neat rapeseed oil. The test was carried out through the four hours continuous engine operation with keeping low load. After the operation, state of deposit formation and fuel dilution in lubricating oil were investigated. Results indicate that Re-entrant piston which creates strong reverse squish and high swirl forms the deposit annular on the piston top. Toroidal piston easily produces deposit on the undersurface of cylinder head. The deposit in the cavity accumulates where initial rapeseed oil spray impinges regardless of piston types. The carbonization of the deposit is promoted on the wall surface where the burned gas with high temperature and high velocity comes into contact. It is important to avoid extremely strong reverse squish to the cylinder liner in order to control the fuel dilution. The deep-bowl chamber changes the direction of reverse squish from the cylinder liner direction to the cylinder head direction. The low velocity outflow from the piston cavity reduces the adhesion of unburned fuel on the cylinder liner, resulting in the smaller amount of unburned fuel scraped off by a piston ring

Microbiome composition comparison in oral and atherosclerotic plaque from patients with and without periodontitis

There is no conclusive evidence regarding a causal relationship between periodontitis and atherosclerosis. In this study, we examined the microbiome in the oral cavity and atheromatous plaques from atherosclerosis patients with or without periodontitis to investigate the role of oral bacteria in the formation of atheromatous plaques. We chose four patients with and without periodontitis, who had undergone carotid endarterectomy. Bacterial samples were extracted from the tongue surface, from periodontal pocket (during the oral examination), and from the atheromatous plaques (APs). We investigated the general and oral conditions from each patient and performed next-generation sequencing (NGS) analysis for all bacterial samples. There were no significant differences between both groups concerning general conditions. However, the microbiome patterns of the gingival pocket showed differences depending on the absence or presence of periodontitis, while those of the tongue surface were relatively similar. The microbiome pattern of the atheromatous plaques was entirely different from that on the tongue surface and gingival pocket, and oral bacteria were seldom detected. However, the microbiome pattern in atheromatous plaques was different in the presence or absence of periodontitis. These results suggested that oral bacteria did not affect the formation of atheromatous plaques directly

Chiral 2-Aryl Ferrocene Carboxylic Acids for the Catalytic Asymmetric C(sp(3))-H Activation of Thioamides

Enantioselective C-H functionalization reactions using trivalent group 9 metals (Co, Rh, Ir) have been investigated mainly on the basis of the development of well-designed chiral cyclopentadienyl (Cp) ligands. Although it has recently been demonstrated that chiral carboxylic acids combined with achiral Cp-type ligands can enable highly enantioselective C-H functionalization reactions, the structural diversity of the applied chiral acids remains limited. Here, we report that chiral 2-aryl ferrocene carboxylic acids, which are easily obtained from diastereoselective ortho lithiation and Suzuki-Miyaura coupling, can serve as external chiral sources for the Cp*Co-III-catalyzed enantioselective C(sp(3))-H amidation of alpha-aryl thioamides using dioxazolones

Chiral Carboxylic Acid Enabled Achiral Rhodium(III)-Catalyzed Enantioselective C-H Functionalization

Reported is an achiral (CpRhIII)-Rh-x/chiral carboxylic acid catalyzed asymmetric C-H alkylation of diarylmethanamines with a diazomalonate, followed by cyclization and decarboxylation to afford 1,4-dihydroisoquinolin-3(2H)-one. Secondary alkylamines as well as nonprotected primary alkylamines underwent the transformation with high enantioselectivities (up to 98.5:1.5 e.r.) by using a newly developed chiral carboxylic acid as the sole source of chirality to achieve enantioselective C-H cleavage by a concerted metalation-deprotonation mechanism

Native Amide-Directed C(sp3)−H Amidation Enabled by Electron-Deficient RhIII Catalyst and Electron-Deficient 2-Pyridone Ligand

Trivalent group-9 metal catalysts with a cyclopentadienyl-type ligand (CpMIII; M=Co, Rh, Ir, Cp=cyclopentadienyl) have been widely used for directed C-H functionalizations, albeit that their application to challenging C(sp(3))-H functionalizations suffers from the limitations of the available directing groups. In this report, we describe directed C(sp(3))-H amidation reactions of simple amide substrates with a variety of substituents. The combination of an electron-deficient (CpRh)-Rh-E catalyst (Cp-E=1,3-bis(ethoxycarbonyl)-substituted Cp) and an electron-deficient 2-pyridone ligand is essential for high reactivity