The aim of this work was to evaluate the dielectric properties of impregnated and activated palm kernel shells (PKSs) samples using two activating agents, potassium carbonate (K2CO3) and sodium hydroxide (NaOH), at three impregnation ratios. The materials were characterized by moisture content, carbon content, ash content, thermal profile and functional groups. The dielectric properties were examined using an open-ended coaxial probe method at various microwave frequencies (1–6 GHz) and temperatures (25, 35, and 45°C). The results show that the dielectric properties varied with frequency, temperature, moisture content, carbon content and mass ratio of the ionic solids. PKSK1.75 (PKS impregnated with K2CO3 at a mass ratio of 1.75) and PKSN1.5 (PKS impregnated with NaOH at a mass ratio of 1.5) exhibited a high loss tangent (tan δ) indicating the effectiveness of these materials to be heated by microwaves. K2CO3 and NaOH can act as a microwave absorber to enhance the efficiency of microwave heating for low loss PKSs. Materials with a high moisture content exhibit a high loss tangent but low penetration depth. The interplay of multiple operating frequencies is suggested to promote better microwave heating by considering the changes in the materials characteristics.

We demonstrated an effective way of preparing melt spinnable mesophase pitches via catalytic hydrogenation of petroleum residue (fluidized catalytic cracking-decant oil) and their subsequent thermal soaking. The mesophase pitches thus obtained were analyzed in terms of their viscosity, elemental composition, solubility, molecular weight, softening point and optical texture. We found that zeolite-induced catalytic hydrogenation under high hydrogen pressure contributed to a large variation in the properties of the pitches. As the hydrogen pressure increased, the C/H ratio decreased, and the solubility in n-hexane increased. The mesophase pitch with entirely anisotropic domains of flow texture exhibited good meltspinnability. The mesophase carbon fibers obtained from the catalytically hydrogenated petroleum residue showed moderate mechanical properties.

Since methyl bromide(MB) has been designated as ozone deplete substance(ODS) by Montreal protocol (1989), many MBalternative fumigants like ethyl formate and phosphine gas were developed and commercialized. Ethyl formate(EF) is an effectiveMB alternative fumigant to control insect pests on imported fresh commodities. It is important to develop a proper evaporationmethod to apply EF on large scale fumigation because EF has a high boiling point(54℃). Recently, concurrent treatment ofethyl formate and nitrogen(EF+N2 treatment) has been newly developed. At preliminary test, EF+N2 treatment showed goodevaporation rate and showed high efficacy on quarantine pests without phytotoxicity on fresh commodities. In this trial, we’veapplied the EF+N2 treatment on imported orange and lemon at pilot scale (0.5m3, 10m3) containers and commercial scale containerto validate efficacy and phytotoxicity. 70g/m3 of EF liquid was applied on orange and lemon by EF+N2 treatment method,and showed 100% mortality on tested insect pest(Tetranychus urticae) without phytotoxicity at 0.5m3 and 10m3 scale fumigationtrials, respectively. At commercial scale trial, EF+N2 treatment also showed 100% efficacy on T. urticae and there was nophytotoxic symptoms on imported orange and lemon fruit. These results indicate that the newly developed EF+N2 treatmenthas a potential as a MB alternative, and can be applied on imported fresh commodities for quarantine and pre-shipment purpose.

The entomopathogenic fungus Metarhizium anisopliae B is a powerful biological control agent against Monochamusalternatus, a crucial mediator of the pinewood nematode Bursaphelenchus xylophilus. In this study, production of destruxins(dtxs), insecticidal cyclic hexadepsipeptides, was monitored in the submerged culture of M. anisopliae B. Three typesof dtxs, i.e., destruxin A, B, and E, were produced during the culture. Among the three dtxs, the production yield ofdestruxin A was best, followed by destruxin B and E. Destruxin A production was increased when pH was controlledat 6.0, whereas production of destruxin E was not affected by the pH control. The highest yield of dtxs A, B, and Ewere 16.4, 7.3, and 6.1 mg L-1, respectively. Considering that process for dtxs production has not been optimized, M.anisopliae B has more powerful implication as a biocontrol agent.

The entomopathogenic fungus Metarhizium anisopliae is one of potent biological control agents against a variety ofinsect pests. In this study, we investigated enzyme production of M. anisopliae strains A and B. They produced extracellularenzymes for degrading the epidermis of Monochamus alternatus, a crucial mediator of the pinewood nematode Bursaphelenchusxylophilus. With Q-TOF MS/MS analysis, 29 kDa protein, a major band on a SDS-PAGE gel, was identified as subtilisin-likeserine protease PR1A. M. anisopliae A produced an extracellular enzyme more efficiently than M. anisopliae B: however,enzyme activities targeted for the cuticle were comparable. Our results suggest that the two strains of M. anisopliae havethe biological potential against M. alternatus with insecticidal protease production.

Ginger is generally consumed as food or medicine in Korea and mostly imported from China. During quarantine inspection,genus of nematodes, Meloidogyne spp. and Pratylenchus spp., are mainly detected and regulated under the procedure ofquarantine in Korea. We tested the susceptibility and mortality rates of Meloidogyne spp., which are infected in ginger,against a fumigant, Ethanedinitrile (EDN). Juveniles of the nematode showed 100 % mortality against EDN at 2.5 mg/Lfor 2 h at 13°C, meanwhile, egg mass showed 0 % hatching at 5 mg/L for 2 h at 13°C. A concentration × time product(CTP) was determined as 7.24 ghm-3. Under the 35% filling rate of ginger in cold chamber, 100% mortality was observedin both juveniles and eggs at 50 mg/L for 2 h at 13°C. At that condition, CTP was determined as 14.12 ghm-3. Basedon this study, EDN fumigation will be effectively apply to control of nematodes.