Pengaruh Insektisida Deltametrin Terhadap Perilaku Orientasi Parasitoid Anagrus Nilaparvatae (Pang Et Wang) (Hymenoptera: Mymaridae)

Host searching behaviour by a parasitoid includes orientation to the volatile compounds (odor) relesead by host or host plant. The aim of this study was to determine the changes in the orientation behaviour of Anagrus nilaparvatae (Pang et Wang), the egg parasitoid of rice brown planthoppers (Nilaparvata lugens (Stål)), after being exposed to sublethal concentrations of deltamethrin. The impact of residue on plants to the behaviour of parasitoid was also studied. The sublethal concentrations (LC10 and LC40) used were 0.023 ppm and 2.235 ppm, respectively. Deltamethrin applied to the rice plants were 12.5 ppm and 6.25 ppm, and its effect was observed at 3 hours, 1, 3 and 7 days after application. Orientation behavior was studied using Y-tube olfactometer. Application of deltamethrin at subletal concentration reduced the ability of surviving A. nilaparvatae to detect odors (volatile ompounds) released by the host, N. lugens. The higher the concentration of deltamethrin applied to the parasitoid or to the rice plants, the more prominent effect observed in the changing in the parasitoid behavious, in particular disruption to the parasitoid's orientation to find their host. As consequences, effects of deltamethrin may lead to reduce the effectiveness of A. nilaparvatae as biological control agents in the field as a result of declining their searching capacity

Distributions of Noble Metal Pd and Pt in Mesoporous Silica

Mesoporous silica nanostructures have been synthesized and loaded with Pd and Pt catalytic noble metals. It is found that Pd forms small nanoclusters (3–5 nm) on the surface of the mesoporous structure whereas Pt impregnation results in the inclusion of Pt nanostructures within the silica hexagonal pores (from nanoclusters to nanowires). It is observed that these materials have high catalytic properties for CO–CH4 combustion, even in a thick film form. In particular, results indicate that the Pt and Pd dispersed in mesoporous silica are catalytically active as a selective filter for gas sensors

Distributions of Nobel Metal Pd and Pt in Mesoporous Silica

Mesoporous silicananostructures have been synthesized and loaded with Pd and Pt catalytic noble metals. It is found that Pd forms small nanoclusters (3–5 nm) on the surface of the mesoporous structure whereas Pt impregnation results in the inclusion of Pt nanostructures within the silica hexagonal pores (from nanoclusters to nanowires). It is observed that these materials have high catalyticproperties for CO–CH4CO–CH4CO–CH4 combustion, even in a thick film form. In particular, results indicate that the Pt and Pd dispersed in mesoporous silica are catalytically active as a selective filter for gas sensors

Surface States in Template Synthesized Tin Oxide Nanoparticles

Tin–oxide nanoparticles with controlled narrow size distributions are synthesized while physically encapsulated inside silica mesoporous templates. By means of ultraviolet-visible spectroscopy, a redshift of the optical absorbance edge is observed. Photoluminescence measurements corroborate the existence of an optical transition at 3.2 eV. The associated band of states in the semiconductor gap is present even on template-synthesized nanopowders calcined at 800 °C, which contrasts with the evolution of the gap states measured on materials obtained by other methods. The gap states are thus considered to be surface localized, disappearing with surface faceting or being hidden by the surface-to-bulk ratio decrease

THE TOTAL IRREGULARITY STRENGTH OF SOME COMPLETE BIPARTITE GRAPHS

This paper deals with the total irregularity strength of complete bipartite graph  where  and . &nbsp

Synthesis of Tin Oxide Nanostructures with Controlled Particle Size Using Mesoporous Frameworks

Tin oxide nanostructures with controlled narrow particle size distribution were synthesized inside silica mesoporous templates. In this way, particle growth was blocked by physically corseting the tin compound inside the silica frameworks, the pore diameter of which determines the final tin oxide crystallite size distribution. Template structures were subsequently eliminated by chemical methods to collect the unsupported semiconductor nanoparticles. Thus obtained tin oxed nanopowders, with particle sizes in the range between 6 and 10 nm, were structurally, chemically, and electically characterized. The results are compared with those obtained from the characterization of larger crystallite materials