Fisheries-based Evaluation of Carrying Capacity for Scallops in Ogatsu Bay

Symposium mini revie

Fisheries-based Evaluation of Carrying Capacity for Scallops in Ogatsu Bay

Oral Session

Conversion of N-acetyl-d-glucosamine to nitrogen-containing chemicals in high-temperature water

Available online 19 July 2019To demonstrate the conversion of renewable biomass to platform chemicals, we previously reported the non catalytic conversion of N-acetyl-D-glucosamine (GlcNAc), which is obtained from chitin, to nitrogen-containing chemicals; however, various aspects of this process were not clarified. Herein, we reported updated and expanded results for the synthesis of nitrogen-containing chemicals from GlcNAc in high-temperature water at 180-280 degrees C and 25 MPa with a reaction time of 5-34 s. The main products were 2-acetamido-2,3-dideoxy-D-erythro-hex-2-enofuranose (Chromogen I) and 3-acetamido-5-(1',2'-dihydroxyethyl)furan (Chromogen III) with the maximum yields of 37.0% and 34.5%, respectively. Although 3-acetamido-5-acetylfuran was expected to form by the dehydration of Chromogen III, a yield of only < 1% was obtained, likely because the dehydration of Chromogen III is difficult in the absence of a catalyst. The evaluation of the effects of acid and base catalysts on the dehydration of GlcNAc revealed that the acid catalyst suppressed the transformation of GlcNAc to Chromogen I and promoted the transformation of Chromogen I to Chromogen III, whereas the base catalyst had the opposite effects on these processes. The synthesis of nitrogen-containing chemicals from GlcNAc in high temperature water is an environmentally benign method for utilizing renewable chitin biomass.ArticleFUEL PROCESSING TECHNOLOGY. 195:106154 (2019)journal articl

Lower tropospheric vertical distribution of aerosol particles over Syowa Station, Antarctica from spring to summer 2004

Vertical distributions of atmospheric aerosol particles were measured nine times up to 5200 m a.s.l. using an aircraft over Syowa Station, East Antarctica during September-December 2004. Measurements were made for number concentrations of condensation nuclei (CN, Dp>10 nm), number-size distribution larger than 0.3 μm diameter, air temperature, humidity, and GPS position. During spring, the vertical profile of CN concentration showed large variability (100-1000 cm^(-3)), but it was mostly constant in summer. Vertical profiles of number-size distribution larger than 0.3 μm showed a systematic shift at altitudes greater than 4000 m. Both concentrations of aerosol number for Dp>0.3 μm and integrated volume between 0.3 and 1.0 μm showed constantly lower values at altitudes greater than 4000 m. These data suggest that the shift of aerosol parameters results from depletion of coarse particles such as sea salts. Maximum concentrations of the volume and CN were obtained respectively from the profiles on 7 October and 29 November 2004. These events are interpreted as sources and transport processes based on synoptic meteorological data, an ocean color index produced by SeaWiFS, and backward air trajectory analysis