Decomposition experiments of microcrystalline cellulose were conducted in subcritical and supercritical water (25 MPa, 320−400 °C, 0.05−10.0 s). At 400 °C hydrolysis products mainly obtained, while 320−350 water, aqueous decomposition glucose the main products. Kinetic studies cellulose, cellobiose, at these conditions showed that below 350 rate was slower than cellobiose rates, above drastically increased became higher rates. Direct observation reaction high-temperature high-pressure by...

In eukaryotic cells, nutrient starvation induces the bulk degradation of cellular materials; this process is called autophagy. yeast Saccharomyces cerevisiae, most ATG (autophagy) genes are involved in not only degradative autophagy, but also a biosynthetic process, cytoplasm to vacuole (Cvt) pathway. contrast, ATG17 gene required specifically To better understand function Atg17, we have performed biochemical characterization Atg17 protein. We found that atg17Δ mutant under condition was...

Abstract Experiments of microcrystalline cellulose conversion in subcritical and supercritical water were conducted at temperatures between 290 400°C, a pressure 25 MPa, residence times 0.02–13.1 s using continuous‐flow‐type microreactor. First, the reaction mechanism was proposed on basis detailed product analyses. Next, kinetic description this grain model carried out to verify consequently found that reaction‐rate models able express identical conditions. © 2004 American Institute...

This study deals with supercritical CO2 extraction of astaxanthin from Haematococcus pluvialis ethanol as an entrainer. The effects pressure, temperature, flow rate, and the existence entrainer concentration on amount total extract, extracted, content in extract were studied. Extractions carried out at pressures 20−55 MPa, temperatures 313−353 K, rates 2−4 mL/min, concentrations 1.67−7.5% (v/v). increased increasing temperature pressure. With higher could be while extracted almost did not...

The kinetics of poly(ethylene terephthalate) (PET) depolymerization in supercritical methanol was investigated to develop a chemical recycling process for postconsumer PET bottles. with high molecular weight (IV value (intrinsic viscosity) = 0.84) depolymerized batch reactor at temperatures between 543 and 573 K under estimated pressures 0.1−15 MPa. In addition weight, low such as its oligomer (trimer), bis-hydroxyethyl terephthalate (BHET), methyl-(2-hydroxyethyl) (MHET), used model...

Abstract Lignin, which is the second most abundant polymeric aromatic organic substance in wood biomass after cellulose, and contains many oxygen‐based functional groups, has been proposed as an alternative source of chemical compounds. Guaiacol, a model compound for lignin, was reacted supercritical water using batch‐type reactor at temperatures 653–673 K various pressures under argon atmosphere. The effects temperature reaction time same pressure were combined into single severity...

Supercritical carbon dioxide (SCCO2) extraction of lycopene from waste tomato skins was investigated. The experiments were carried out at pressures and temperatures ranging 20 to 50 MPa 313 373 K, respectively, without any modifiers. flow rate CO2 maintained 2.5 mL/min for 330 min time. Solvent effect examined rates 1.5 4.5 mL/min. extracts analyzed by high-performance liquid chromatography UV-visible spectroscopy. results showed that with optimized operating conditions, the maximum yield...

Purple witchweed (Striga hermonthica), Orobanchaceae, is an obligate root-parasitic weed of important cereal crops. The parasite a copious seed producer, and huge bank develops soon after the onset initial infestation. To germinate, Striga requires pretreatment in moist warm environment subsequent exposure to exogenous stimulant. One approach reduce artificially induce germination seeds absence or away from host roots. A newly developed stimulant for S. hermonthica, designated as T-010, was...

Retro-aldol condensation of glucose occurred preferentially relative to dehydration and isomerization under low water density conditions in supercritical water, glycolaldehyde was successfully produced a rapid selective manner without any catalyst.

Depression is common in Alzheimer's disease (AD). Clinicoanatomic studies focal brain injuries and functional imaging both primary depression secondary to neurologic diseases have demonstrated involvement of the frontal lobe. Frontal has not been established AD. We studied correlation between metabolic abnormalities In 53 patients with probable AD minimal moderate disability, we assessed severity using Neuropsychiatric Inventory correlated score regional cerebral glucose metabolism...

ABSTRACT Supercritical water liquefaction and gasification is reviewed with the introduction of some recent findings by authors. suitable for recovery energy from wet biomass while supercritical opens door to effective treatment species in terms material recovery. Cellulose, one main components biomass, completely dissolved water. Once dissolved, reaction cellulose can take place swiftly hydrolysis pyrolysis. The reaction, otherwise slower than pyrolysis due mass transfer limitation, faster...

Reactions of cellobiose in subcritical and supercritical water were studied. Kinetic study on the decomposition clarified that contribution hydrolysis to overall rate decreased retro-aldol condensation greatly increased with decreasing pressure near-critical water. It was found expressed as a first-order reaction law kinetic parameters this estimated. With regards cellobiose, it indicated second-order (first-order concentration) its activation energy preexponential factor determined....