Performance of Soil Termiticides in Open Field and Under Roof Overhang

The study investigated the difference in performance of termiticides using concrete slab test installed in open field and under roof overhang.  Soil treated with cypermethrin and chlorpyrifos under roof overhang showed lower percentage of termite penetration compared to those in open field in each year of evaluation.  However, in both conditions termites were already able to penetrate treated plots during the first year of trial.  The high percentage of plots attacked by termites could be attributed to several environmental factors such as presence of a wider diversity of termite species, moisture, temperature, soil properties, microbial communities, etc. common in tropical climates.  The results from these two modes of installation could affect protocol used for field trial and the granting of registration or performance warranty to candidate termiticides in tropical countries

Repellent Effects of Annona Crude Seed Extract on the Asian Subterranean Termite Coptotermes gestroi Wasmann (Isoptera:Rhinotermitidae)

Crude seed extract of three tropical fruits belonging to the family Annonaceae, viz., sweetsop (Annona squamosa L.), soursop (A. muricata L.) and biriba (Rollinia mucosa Baill.) were investigated for their repellent effects on the Asian subterranean termite Coptotermes gestroi Wasmann (Isoptera: Rhinotermitidae).  Results of laboratory feeding bioassay (choice and no-choice) indicated that crude extract of A. squamosa, A. muricata and R. mucosa had feeding deterrent effects on C. gestroi.  Termites showed significant avoidance behavior to filter paper treated with extracts of the three Annona species investigated.  Soil barrier test revealed that Annona extracts were able to limit penetration of C. gestroi in laboratory tunneling test.  The results suggest that Annona seed extracts may offer an alternative source of natural insecticide against subterranean termites

Effects of Supercritical Fluid Treatments on Physical Properties of Wood-Based Composites

The effects of supercritical fluid (SCF) impregnation on physical properties of composites were investigated at various pressures, temperatures, and treatment times with carbon dioxide as the fluid and tebuconazole as a biocide. In general, within the ranges tested, SCF treatment had no negative effects on modulus of rupture, (MOR), modulus of elasticity, (MOE), or dimensional stability of particleboard, flakeboard, or medium-density fiberboard; in some instances, SCF treatment appeared to be associated with slight property improvements in some panel types. Shear tests of plywood suggested a similar lack of treatment effect. Results indicate that, despite the elevated pressure employed during the process, SCF impregnation does not adversely affect the mechanical properties of various wood-based composites

Effect of process variables on supercritical fluid impregnation of composites with tebuconazole

This study examines the effects of pressure, temperature, and treatment time on supercritical fluid impregnation of such composites as plywood, particleboard, flakeboard, and medium-density fiberboard. Carbon dioxide with methanol as a cosolvent was used as the supercritical fluid, with tebuconazole as the biocide. Biocide distribution, as measured by extraction and analysis, generally increased with pressure, temperature, and treatment time, although the retentions sometimes decreased at the highest pressure tested (4500 psig). In general, biocide retentions were far above those required for fungal protection, and the distribution was more uniform than that found with conventional pressure treatments. The results suggest that supercritical fluid impregnation represents a simple method for impregnating composites with biocides without the permanent damage typical of other treatment systems.Keywords: composites, tebuconazole, supercritical fluids, waferboard, carbon dioxide, flakeboard, fiberboard, plywood, particleboard, pressure treatmen

Effects of supercritical fluid treatments on physical properties of wood-based composites

The effects of supercritical fluid (SCF) impregnation on physical properties of composites were investigated at various pressures, temperatures, and treatment times with carbon dioxide as the fluid and tebuconazole as a biocide. In general, within the ranges tested, SCF treatment had no negative effects on modulus of rupture (MOR), modulus of elasticity (MOE), or dimensional stability of particleboard, flakeboard, or medium-density fiberboard; in some instances, SCF treatment appeared to be associated with slight property improvements in some panel types. Shear tests of plywood suggested a similar lack of treatment effect. Results indicate that, despite the elevated pressure employed during the process, SCF impregnation does not adversely affect the mechanical properties of various wood-based composites.Keywords: particleboard, supercritical fluid, SCF, strength properties, tebuconazole, plywood, flakeboard, composites, preservative treatment, medium-density fiberboar

Iso-conversional kinetic and thermodynamic analysis of catalytic pyrolysis for palm oil wastes

This chapter presents the comparative studies related to the kinetic and thermodynamic analysis of the pyrolysis of oil palm frond (OPF) and oil palm trunk (OPT) that are investigated in the absence and presence of OPF ash, OPT ash, and OPF/OPT ash using thermogravimetric approach (TGA). OPF ash, OPT ash, and OPF/OPT ash are used as natural catalysts in the pyrolysis process of palm oil wastes. The experiments are conducted at various heating rates ranging 10–100 K min−1 from temperature of 323K to 1,173K. Iso-conversional kinetic models such as Coats-Redfern, Vyazovkin, and Miura-Maki model are the selected kinetic models to predict the kinetic parameters such as activation energy (EA) and preexponential factor. The average EA values ranged 28.49–211.69 kJ.mol−1 and 44.00–168.06 kJ.mol−1 for pyrolysis of OPF and OPT, respectively. Meanwhile, the average EA values ranged from 22.66–182.91 kJ.mol−1 and 36.86–269.67 kJ.mol−1 for the catalytic pyrolysis of OPF and OPT respectively

Toxicity, Tunneling and Feeding Behavior of the Termite, Coptotermes vastator, in Sand Treated with Oil of the Physic Nut, Jatropha curcas

Oil of the physic nut, Jatropha curcas L. (Malpighiales: Euphorbiaceae), was evaluated in the laboratory for its barrier and repellent activity against the Philippine milk termite Coptotermes vastator Light (Isoptera: Rhinotermitidae). The study showed that J. curcas oil had anti-feeding effect, induced reduction in tunneling activity and increased mortality in C. vastator. Behavior of termites exposed to sand treated with J. curcas oil indicated that it is toxic or repellent to C. vastator. Toxicity and repellent thresholds, were higher than those reported for other naturally occurring compounds tested against the Formosan subterranean termite

Repellent Effects of Annona Crude Seed Extract on the Asian Subterranean Termite Coptotermes gestroi Wasmann (Isoptera:Rhinotermitidae)

Crude seed extract of three tropical fruits belonging to the family Annonaceae, viz., sweetsop (Annona squamosa L.), soursop (A. muricata L.) and biriba (Rollinia mucosa Baill.) were investigated for their repellent effects on the Asian subterranean termite Coptotermes gestroi Wasmann (Isoptera: Rhinotermitidae).  Results of laboratory feeding bioassay (choice and no-choice) indicated that crude extract of A. squamosa, A. muricata and R. mucosa had feeding deterrent effects on C. gestroi.  Termites showed significant avoidance behavior to filter paper treated with extracts of the three Annona species investigated.  Soil barrier test revealed that Annona extracts were able to limit penetration of C. gestroi in laboratory tunneling test.  The results suggest that Annona seed extracts may offer an alternative source of natural insecticide against subterranean termites

Performance of Soil Termiticides in Open Field and Under Roof Overhang

The study investigated the difference in performance of termiticides using concrete slab test installed in open field and under roof overhang.  Soil treated with cypermethrin and chlorpyrifos under roof overhang showed lower percentage of termite penetration compared to those in open field in each year of evaluation.  However, in both conditions termites were already able to penetrate treated plots during the first year of trial.  The high percentage of plots attacked by termites could be attributed to several environmental factors such as presence of a wider diversity of termite species, moisture, temperature, soil properties, microbial communities, etc. common in tropical climates.  The results from these two modes of installation could affect protocol used for field trial and the granting of registration or performance warranty to candidate termiticides in tropical countries