Histochemical and ultrastructural evidence of lipid secretion by the silk gland of the sugarcane borer Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae)

The silk gland in Lepidoptera larvae is responsible for the silk production used for shelter or cocoon construction. The secretion of fibroin and sericin by the different silk gland regions are well established. There are few attempts to detect lipid components in the insect silk secretion, although the presence of such element may contribute to the resistance of the shelter to wet environment. This study characterizes the glandular region and detects the presence of lipid components in the secretion of the silk gland of Diatraea saccharalis (Fabricius). The silk gland was submitted to histochemical procedure for lipid detection or conventionally prepared for ultrastructural analyses. Lipid droplets were histochemically detected in both the apical cytoplasm of cell of the anterior region and in the lumen among the microvilli. Ultrastructural analyses of the anterior region showed lipid material, visualized as myelin-like structures within the vesicular Golgi complex and in the apical secretory globules, mixed up with the sericin; similar material was observed into the lumen, adjacent to the microvilli. Lipids were not detected in the cells neither in the lumen of the posterior region. Our results suggest that the silk produced by D. saccharalis has a minor lipid content that is secreted by the anterior region together with the sericin.

Evolution of the mechanical properties of a tropical soil stabilized with lime and ash of rice rind

The ash of rice rind is a pozzolanic material that reacts with the calcium hydroxide (Ca (OH)2) forming bonding composites, when finely worn out and in water presence. Considering this behavior, the objective of the present work was to evaluate the potential use of this residue in the enrichment of the content of pozzolanic materials of a tropical soil stabilized with a commercial hydrated lime. The laboratory testing program incorporated unconfined compression strength tests performed on the soil and on its mixtures with contents of 8% of lime enriched with 5 and 10% of ash of rice rind in relation to the soil dry mass. The results of the testing program supported that the use of the residue was effective in increasing the degree of reactivity of the soil that was also directly related with the increase in the ash content and the period of cure of the mixtures.

Glass-ceramic material from the SiO 2-Al 2O 3-CaO system using sugar-cane bagasse ash (SCBA)

Brazil is the world's largest producer of alcohol and sugar from sugarcane. Currently, sugarcane bagasse is burned in boilers to produce steam and electrical energy, producing a huge volume of ash. The major component of the ash is SiO 2, and among the minor components there are some mineralizing agents or fluxing. Published works have shown the potential of transforming silicate-based residues into glass-ceramic products of great utility. This work reports the research results of SCBA use to produce glass-ceramics with wollastonite, rankinite and gehlenite as the major phases. These silicates have important applications as building industry materials, principally wollastonite, due to their special properties: high resistance to weathering, zero water absorption, and hardness among others. The glasses (frits) were prepared mixing ash, calcium carbonate and sodium or potassium carbonates as flux agents, in different concentrations. X-ray fluorescence was used to determine the chemical composition of the glasses and their crystallization was assessed by using thermal analysis (DTA/DSC/TGA) and X-ray diffraction. The crystallization kinetics was evaluated using the Kissinger method, giving activation energies ranging from 200 to 600 kJ/mol. © 2011 Ceramic Society of Japan.

Characterization and impact of the sugarcane borer on sugarcane yield and quality

The sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), is a key pest of sugarcane (Saccharum spp.). While damage caused by this pest has increased in the past 20 yr, studies investigating the insect-plant interactions are still lacking. Moreover, there is no information about the consequences of borer damage on the parameters of sugar quality. Therefore, two field experiments were performed during the 2010 and 2011 growing seasons in Brazil to compare the raw material and sugar quality of SP80-3280 sugarcane plants with and without the sugarcane borer. Plants were protected within screen cages and infested weekly during the 2010 and 2011 seasons, using egg masses starting at the second and third internode stage. At harvest, 25.77 and 19.01% of the internodes were bored by larvae (infestation intensity, II) in the first and second seasons, respectively. There was no correlation between the borer gallery total volume and II. The fiber content significantly increased with increasing II. The stalk biometric parameters, such as length, diameter, and yield, were not correlated with II. The sucrose yield significantly decreased with increasing II. Consequently, sugar yield losses were estimated at 8.83 and 19.80% per 1% bored internode for the first and second seasons, respectively. The concentration of phenolic compounds increased, and unclarified juice color quality decreased, with increasing II. Significant differences were detected in the quality of the sugar. These results should be confirmed for other sugarcane cultivars and incorporated into an economic injury level to enhance decision-making strategies for borer management. © 2013 by the American Society of Agronomy, 5585 Guilford Road, Madison, WI 53711. All rights reserved.

Use of slag/sugar cane bagasse ash (SCBA) blends in the production of alkali-activated materials

Blast furnace slag (BFS)/sugar cane bagasse ash (SCBA) blends were assessed for the production of alkali-activated pastes and mortars. SCBA was collected from a lagoon in which wastes from a sugar cane industry were poured. After previous dry and grinding processes, SCBA was chemically characterized: it had a large percentage of organic matter (ca. 25%). Solutions of sodium hydroxide and sodium silicate were used as activating reagents. Different BFS/SCBA mixtures were studied, replacing part of the BFS by SCBA from 0 to 40% by weight. The mechanical strength of mortar was measured, obtaining values about 60 MPa of compressive strength for BFS/SCBA systems after 270 days of curing at 20 °C. Also, microstructural properties were assessed by means of SEM, TGA, XRD, pH, electrical conductivity, FTIR spectroscopy and MIP. Results showed a good stability of matrices developed by means of alkali-activation. It was demonstrated that sugar cane bagasse ash is an interesting source for preparing alkali-activated binders. © 2013 by the authors; licensee MDPI, Basel, Switzerland.

Impact strength and abrasion resistance of high strength concrete with rice husk ash and rubber tires

The paper discusses the application of High Strength Concrete (HSC) technology for concrete production with the incorporation of Rice Husk Ash (RHA) residues by replacing a bulk of the material caking and rubber tires with partial aggregate volume, assessing their influence on the mechanical properties and durability. For concrete with RHA and rubber, it was possible to reduce the brittleness by increasing the energy absorbing capacity. With respect to abrasion, the RHA and rubber concretes showed lower mass loss than the concrete without residues, indicating that this material is attractive to be used in paving. It is thus hoped that these residues may represent a technological and ecological alternative for the production of concrete in construction works.

Valorization of sugarcane bagasse ash: Producing glass-ceramic materials

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Interaction between N-fertilizer and water availability on borer-rot complex in sugarcane

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Sugarcane Bagasse Ash as a Reinforcing Filler in Thermoplastic Elastomers: Structural and Mechanical Characterizations

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Binding analysis of Bacillus thuringiensis Cry1 proteins in the sugarcane borer, Diatraea saccharalis (Lepidoptera: Crambidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sugarcane bagasse ash: new filler to natural rubber composite

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization of a wollastonite glass-ceramic material prepared using sugar cane bagasse ash (SCBA) as one of the raw materials

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Testis morphology and dichotomic spermatogenesis in the sugarcane borer Diatraea saccharalis (F.) (Lepidoptera: Crambidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)