No abstract

Bio-based compounds (FmHPM and FdHPM) with a furan backbone and photo-polymerizable 2-hydroxypropyl methacrylate (HPM) group(s) were synthesized from carbohydrate-derived furanyl alcohols (furan-2-methanol and furan-2,5-dimethanol) and their photo-polymerizing behaviors and mechanical properties after photo-polymerization were investigated. Half time values (t 1/2 ) of bio-based FmHPM and FdHPM were 10.4 s and 3.0 s and their shrinkage ratios were 3.0 and 6.1% during photo-polymerization, respectively. Tensile-shear strength of glass and polycarbonate joints bonded by bio-based furanic compounds appeared in range of 0.2-0.6 MPa and pencil hardness of film coated by bio-based furanic compounds after photo-polymerization showed 2H-3H. Newly synthesized bio-based furanic compounds allowed the feasibility to alternate petroleum-based Bis-GMA/TEGDMA, photo-polymerizable composition widely utilized in a variety of applications.

It has been considered that fishing areas for shrimp beam trawl have been in ruin because Korean local governments have permitted trawling into the areas limited by the fisheries local regulations from 1994.Physical and biological effects of the trawling were investigated in the study. Physical effects were investigated by optical methods such as trawling tracking by side scan sonar and comparing the gear both before and after trawling. Biological aspects were investigated by grab sampling of benthic animals, concentration of trace metals in sediment and a flux evaluation of NH4 + , PO4 , and SiO2 by coring. The fishing activity had physical impacts on the seabed but these recovered naturally in less than fourty days naturally, which increased the benthic biodiversity, increases the trace metal concentration of and nutrient flux into the seawater, especially phosphate and silicate. This method and these results can help in further studies looking for disturbances by fishing.