Note on the ∂-problem on the complex ellipsoid

Let D be a complex ellipsoid in C^n. In this paper we study Holder estimates for solutions of the ∂^^--problem in D

Hannaella oleicumulans sp. nov. and Hannaella higashiohmiensis sp. nov., two novel oleaginous basidiomycetous yeast species

滋賀県の土壌から新種の油脂酵母2種を発見 --日本の土壌微生物の可能性を開拓--. 京都大学プレスリリース. 2023-10-04.Two-of-a-kind strike oil: Discovery of oil-forming yeast species boosts hope for reducing carbon dioxide emissions. 京都大学プレスリリース. 2023-10-04.Three strains of novel oleaginous yeast species were isolated from soil samples collected in Shiga Prefecture, Japan. The sequences of the internal transcribed spacer (ITS) region and the D1/D2 region of the large subunit (LSU) of the rRNA genes indicated that these novel yeast species are members of the genus Hannaella. The results of molecular phylogenetic analysis indicated that strains 38–3 and 8s1 were closely related to Hannaella oryzae. They differed by 10 nucleotide substitutions and one gap (1.77 %) in the D1/D2 region of the LSU of the rRNA genes and by 17–18 nucleotide substitutions and 10–11 gaps (5.45–5.85 %) in the ITS region. Strain 51–4 differed from the type strain of the most closely related species, Hannaella pagnoccae, by 26 nucleotide substitutions (4.46 %) in the D1/D2 region of the LSU of the rRNA genes and by 20 nucleotide substitutions and six gaps (5.42 %) in the ITS region. The names proposed for these previously undescribed species are Hannaella oleicumulans sp. nov. and Hannaella higashiohmiensis sp. nov

Burn Time Correction of Start-Up Transients for CAMUI Type Hybrid Rocket Engine

Burn time errors caused by various start-up transient effects have a significant influence on the regression modelling of hybrid rockets. Their influence is especially pronounced in the simulation model of the Cascaded Multi Impinging Jet (CAMUI) hybrid rocket engine. This paper analyses these transient burn time errors and their effect on the regression simulations for short burn time engines. To address these errors, the equivalent burn time is introduced and is defined as the time the engine would burn if it were burning at its steady-state level throughout the burn time to achieve the measured total impulse. The accuracy of the regression simulation with and without the use of equivalent burn time is then finally compared. Equivalent burn time is shown to address the burn time issue successfully for port regression and, therefore, also for other types of cylindrical port hybrid rocket engines. For the CAMUI-specific impinging jet fore-end and back-end surfaces, though, the results are inconclusive

Investigation of Graphite Nozzle Erosion in Hybrid Rockets Using Oxygen/High-Density Polyethylene

A recently developed reconstruction technique is used to investigate graphite nozzle erosion in two scales of hybrid rocket motors, 30-N-thrust class and 2000-N-thrust class, using oxygen as the oxidizer and high-density polyethylene as the fuel. Thermocouple measurements taken from within the nozzles are used to estimate nozzle throat wall temperature. Forty-four static firing tests were conducted under varying experimental conditions to confirm the validity of the reconstruction technique results, to investigate the conditions at the onset of erosion, and to formulate an empirical predictive model of nozzle erosion rate. Results show that a single formula that treats the combustion gas as a single oxidizing agent for which heterogenous rate constants are functions of equivalence ratio can satisfactorily replicate the erosion rate of graphite by a combustion gas containing multiple oxidizing species. Furthermore, the chemical-kinetic-limited conditions of the onset of nozzle erosion are specified by a novel empirical correlation, which shows that erosion begins at lower temperature and pressure in oxidizer-rich combustion gas than in fuel-rich combustion gas