Variación anual de las propiedades insecticidas de Peumus boldus sobre Sitophilus zeamais

The objective of this work was to determine the annual variation of Peumus boldus Molina insecticidal properties for the control of Sitophilus zeamais Motschulsky, under laboratory conditions. The powder of P. boldus leaves was evaluated, during 12 months, in 0.5, 1, and 2% (w/w) concentrations. Thirty-six treatments, with three replications, were evaluated in a completely randomized experimental design, with a factorial arrangement. Evaluations were made for adult and immature insect percentage mortality and emergence, grain weight loss and seed germination. The greatest mortality was obtained in August and September 2003, in the three concentrations with 100%, and the lowest mortality was registered in May 2003, when only 2% (w/w) reached almost 100% mortality. The lowest adult insect emergence and weight loss were obtained in the same treatments. The effect on immature stages was lower than on adults; and grain germination was affected by P. boldus powders. Insecticidal properties of P. boldus leaves powder are not stable during the year; May is the month with lesser insecticide efficacy; and the powder affects grain germination.The objective of this work was to determine the annual variation of Peumus boldus Molina insecticidal properties for the control of Sitophilus zeamais Motschulsky, under laboratory conditions. The powder of P. boldus leaves was evaluated, during 12 months, in 0.5, 1, and 2% (w/w) concentrations. Thirty-six treatments, with three replications, were evaluated in a completely randomized experimental design, with a factorial arrangement. Evaluations were made for adult and immature insect percentage mortality and emergence, grain weight loss and seed germination. The greatest mortality was obtained in August and September 2003, in the three concentrations with 100%, and the lowest mortality was registered in May 2003, when only 2% (w/w) reached almost 100% mortality. The lowest adult insect emergence and weight loss were obtained in the same treatments. The effect on immature stages was lower than on adults; and grain germination was affected by P. boldus powders. Insecticidal properties of P. boldus leaves powder are not stable during the year; May is the month with lesser insecticide efficacy; and the powder affects grain germination.El objetivo del presente trabajo fue determinar la variación anual en las propiedades insecticidas de Peumus boldus Molina, en el control de Sitophilus zeamais Motschulsky, bajo condiciones de laboratorio. El polvo de hojas de P. boldus se evaluó durante 12 meses, en concentraciones de 0,5, 1 y 2% (p/p). Se evaluaron 36 tratamientos con tres repeticiones, en un diseño experimental completamente al azar, con un arreglo factorial. Se determinó el porcentaje de mortalidad y emergencia de insectos adultos e inmaduros y pérdida de peso y germinación del grano. La mayor mortalidad se obtuvo en los meses de agosto y septiembre de 2003, para las tres concentraciones con un 100%, mientras que la menor fue en mayo de 2003, cuando solo la concentración de 2% fue próxima a 100% de mortalidad. La menor emergencia de insectos adultos y pérdida de peso se obtuvieron en los mismos tratamientos. El efecto sobre estados inmaduros fue menor que contra adultos, y la germinación de los granos de maíz fue afectada por los polvos de P. boldus. Las propiedades insecticidas del polvo de hojas de P. boldus no son estables durante el año, Mayo es el mes con la menor eficacia insecticida, y la germinación de las semillas se ve afectada por el polvo

Polvos de especias arom\ue1ticas para el control del gorgojo del maiz, Sitophilus zeamais Motschulsky, en trigo almacenado

The maize weevil, Sitophilus zeamais Motschulsky, is considered one of the most important pests of stored grains. Plant powders from nine seasoning spices were tested in the laboratory to control S. zeamais at 0,5, 1, 2 and 4% (w/w). The variables evaluated were mortality and emergence (F1) of adult insects, grain weight loss and grain germination. The repellent and fumigant effects were evaluated at concentrations of 0.5, 1, 2 and 4%; the experimental design was completely randomized, with four replicates, and the group of treatments was repeated three times. The highest mortality percentages were obtained with Piper nigrum L. at 1% (83.4%), 2% (97.6%) and 4% (100%). The lowest adult insect emergence was obtained with the same treatments more Capsicum annuum var. longum Sendtn., Cinnamomum zeylanicum Blume and Pimpinella anisum L. at 4% (w/w). No significant differences were recorded as regards grain weight loss and germination. All the plant powders tested had a repellent effect on Sitophilus zeamais and no fumigant effect was recorded.El gorgojo del ma\uedz Sitophilus zeamais Motschulsky,es considerado una de las plagas mas importantes de productos almacenados. Se evaluaron, en laboratorio, polvos vegetales provenientes de nueve especias condimentarias para el control de S. zeamais en concentraciones de 0,5; 1; 2 y 4%. Las variables evaluadas fueron mortalidad y emergencia (F1) de adultos y p\ue9rdida de peso y germinaci\uf3n del grano. Tambi\ue9n se evalu\uf3 el efecto repelente y fumigante a las concentraciones de 0,5; 1 y 2%. El dise\uf1o experimental fue completamente al azar, los tratamientos tuvieron cuatro repeticiones y el grupo de tratamientos fue repetido tres veces. Las mayores mortalidades se obtuvieron con Piper nigrum L. a 1% (83,4%), 2% (97,6%) y 4% (100%). Las menores emergencias de insectos adultos se obtuvieron en los mismos tratamientos m\ue1s Capsicum annuum var. Longum Sendtn., Cinnamomum zeylanicum Blime y Pimpinella anisum L. al 4% (p/p). La p\ue9rdida de peso y germinaci\uf3n de granos no registraron diferencia significativa. Todos los polvos vegetales fueron repelentes para Sitophilus zeamais y ninguno tuvo efecto fumigante

Control de Sitophilus zeamais con polvos vegetales de tres especies del género Chenopodium

Powders of Chenopodium ambrosioides L., Chenopodium album L. and Chenopodium quinoa Willd. were evaluated under laboratory conditions for Sitophilus zeamais Motschulsky control. Evaluated parameters were insect mortality and adult emergence, grain weight loss, grain germination and the following effects of powders: ovicide and larvicide, fumigant, repellent and residual. A completely randomized experimental design with factorial arrangement and three replicates was used. The highest levels of insect mortality were obtained with the powders of Chenopodium ambrosioides L. inflorescence and the mixture of leaves and stems at 2% (w/w), with values of 69.4% and 67.9% respectively. Best emergence reductions were obtained with the same treatments. In all treatments with powders of C. ambrosioides seeds weight were reduced in less than 3%. The residual effect lasted for 15 days, obtaining a mortality of 98.3% of adult insects, when powders of C. ambrosioides inflorescence were used at 2% (w/w) concentration. Powders of C. ambrosioides showed a mortality of 100% of eggs and larvae, and a fumigation effect against adult insects with a mortality of 100% in all treatments was evaluated. Powders of C. ambrosioides have a repellent effect for S. zeamais.Powders of Chenopodium ambrosioides L., Chenopodium album L. and Chenopodium quinoa Willd. were evaluated under laboratory conditions for Sitophilus zeamais Motschulsky control. Evaluated parameters were insect mortality and adult emergence, grain weight loss, grain germination and the following effects of powders: ovicide and larvicide, fumigant, repellent and residual. A completely randomized experimental design with factorial arrangement and three replicates was used. The highest levels of insect mortality were obtained with the powders of Chenopodium ambrosioides L. inflorescence and the mixture of leaves and stems at 2% (w/w), with values of 69.4% and 67.9% respectively. Best emergence reductions were obtained with the same treatments. In all treatments with powders of C. ambrosioides seeds weight were reduced in less than 3%. The residual effect lasted for 15 days, obtaining a mortality of 98.3% of adult insects, when powders of C. ambrosioides inflorescence were used at 2% (w/w) concentration. Powders of C. ambrosioides showed a mortality of 100% of eggs and larvae, and a fumigation effect against adult insects with a mortality of 100% in all treatments was evaluated. Powders of C. ambrosioides have a repellent effect for S. zeamais.Se evaluaron polvos vegetales de Chenopodium ambrosioides L., Chenopodium album L. y Chenopodium quinoa Willd. para el control de Sitophilus zeamais Motschulsky, bajo condiciones de laboratorio. Los parámetros evaluados fueron mortalidad y emergencia de insectos adultos, pérdida de peso y germinación de los granos, efecto ovicida y larvicida, fumigación, repelencia y residualidad de los polvos. El diseño experimental fue completamente al azar, con un arreglo factorial y tres repeticiones. La mayor mortalidad de insectos se obtuvo con los polvos de la inflorescencia y la mezcla de hojas y tallos de Chenopodium ambrosioides L., al 2% (p/p) con valores de 69,4% y 67,9% respectivamente. La menor emergencia de adultos se obtuvo con los mismos tratamientos. La pérdida de peso de granos, en todos los tratamientos de C. ambrosioides, no superó el 3%. Para el tratamiento inflorescencia de C. ambrosioides al 2% (p/p), la residualidad de los polvos se mantuvo hasta los 15 días, con una mortalidad de 98,3%. Esta misma especie presentó una mortalidad de huevos y larvas de 100%, además de presentar un efecto fumigante con una mortalidad de adultos de 100%, en todos los tratamientos evaluados. El polvo de C. ambrosioides es repelente para S. zeamais

Modelling Aspects in Forming and Welding of Nickel-Base Superalloys

The reduction of fuel consumption and carbon dioxide emissions are currently a key factor for the aviation industry because of major concerns about climate change and more restrictive environmental laws. One way to reduce both fuel consumption and CO2 emissions is by significantly decreasing the weight of vehicles while increasing the efficiency of the engine. To meet these requirements, the European aero-engine industry is continuously focusing on improved engine designs and alternative manufacturing methods for load-carrying structures in advanced materials, such as titanium and nickel-base superalloys. These new manufacturing methods involve sheet-metal parts, small castings, and forgings assembled using welding, enabling flexible designs where each part is made of the most suitable materials and states, with advantages such as reduced product cost, lower weight, and increased engine efficiency. In this thesis, a manufacturing process chain including forming and welding in two nickel-base superalloys, alloy 718 and Haynes® 282®, is studied. The aim of this work is to determine which aspects within the material and process are the most relevant to accurately predict the amount of shape distortions that occur along the manufacturing chain. The effect of the forming temperature on the predicted springback is included. The results are compared with experimental cold and hot forming tests with a subsequent welding procedure. During forming of a double-curved component in alloy 718 at room temperature, open fractures are observed in the drawbead regions, which could not be predicted while evaluating the formability of the material based on Nakazima tests and forming limit curves (FLC). The generalised incremental stress-state dependent damage model (GISSMO) is calibrated and coupled with the anisotropic Barlat Yld2000-2D material model to accurately predict material failure during forming using LS-DYNA. The mechanical properties of alloy 718 are determined via uniaxial tensile, plane strain, shear, and biaxial tests at 20 °C. The deformations are continuously evaluated using the digital image correlation (DIC) system ARAMIS™. Numerical predictions are able to accurately predict failure on the same regions as observed during the experimental forming tests. Comparisons of the distribution of damage on one of the drawbeads, between simulations and damage measurements by acoustic emission, indicate that higher damage values correspond to bigger micro cracks. The history from the sheet-metal forming procedure, i.e. residual stresses, strains, element thickness, and geometry, is used as the input for the FE analysis of a subsequent welding procedure of a strip geometry in alloy 718 and Haynes® 282®. A comprehensive characterization of the elasto-plastic properties of both alloys between 20 and 1000 °C is included. Other temperature-dependent properties are extracted from JMatPro-v9 for the corresponding specific batches. The results from the simulations show that the welding procedure further increases the shape distortions over the part. Encouraging agreement was found between the model predictions and the results of forming and welding tests in alloy 718. The findings underscore the importance of including the material history and accurate process conditions along the manufacturing chain to both the prediction accuracy of accumulated shape distortions, and to the potential for the industry. The work also comprises hot forming of the double-curved component in alloy 718 and Haynes® 282®. The presence and nature of serrations due to the dynamic strain aging (DSA) phenomenon between 300 and 800 °C is studied. Microstructural observations are consistent with the behaviour of the material at the different temperatures tested. The residual stresses obtained from the hot forming simulations are transformed based on the stress-relaxation tests performed at high temperatures ranging from 700 to 1000 °C. The results show the importance of using the novel modelling approach combining the anisotropic Barlat Yld2000-2D material model with the thermo-mechanical properties and stress-relaxation behaviour of the material to predict the final geometry of the component with high accuracy. A welding simulation of a bi-metallic strip geometry obtained from the hot formed double-curved component is performed numerically. The effect of the two superalloys on the shape distortions over the part is discussed.Virtual process chain for superalloy sheet metal aero engine structures - Validation and demonstrator (NFFP6)Validation of a fabrication procedure for bi-metallic aero engine components in superalloys (NFFP7

Eficacia de Peak Plus® en el control de Caliroa cerasi (Hymenoptera: Tenthredinidae)

The pear slug (Caliroa cerasi L.) is an important pest of sweet cherries in Chile. It attacks during the harvest and can only be controlled by organosynthetic insecticides. The objective of this study was to evaluate the effect of fatty acids (Peak Plus®) of low risk of toxicity on mammals. The mortality and median lethal concentration (LC50) of Peak Plus® against C. cerasi was determined under laboratory conditions using ten larvae fed on leaf disks in Petri dishes. The insecticide efficacy and foliar damage were evaluated under field conditions on sweet cherry cv. Bing. Treatments were arranged as randomized complete block design with six treatments replicated four times. The LC50 obtained was 1.14 g · L-1 and LC90 was 2.7 g · L-1 24 h after treatments. In the field, Peak Plus® at a concentration of 10 g · L-1 showed high efficacy against C. cerasi, similar to the effects obtained with fenvalerate and methidathion. Peak Plus® at the highest rate decreased foliar damage in a similar way to other insecticides currently used. Finally, we concluded that Peak Plus® is an efficient alternative to organosynthetic insecticides in the control of C. cerasi of sweet cherry.El chape del cerezo es una de las plagas más importantes del cerezo debido a que el ataque se produce durante la cosecha y su control se basa solamente en insecticidas sintéticos. El objetivo de este trabajo fue evaluar un ácido graso de baja toxicidad para mamíferos. En laboratorio, en placas Petri con diez larvas, se estimó mortalidad y concentración letal 50% (CL50) de Peak Plus® sobre Caliroa cerasi L. Se evaluaron cinco concentraciones de Peak Plus® más un testigo absoluto, con cuatro repeticiones y un diseño experimental completamente al azar. Se evaluaron seis tratamientos, incluyendo un testigo absoluto, con cinco repeticiones en un diseño experimental de bloques completamente al azar. En laboratorio, los valores de CL50 y CL90 a las 24 h fueron de 1,14 g·L-1 y de 2,7 g·L-1 respectivamente. En campo, Peak Plus® a una concentración de 10 g·L-1 fue tan efectivo en el control de C. cerasi como fenvalerato y metidation. Peak Plus® detuvo el daño foliar al igual que los insecticidas usados comúnmente. Finalmente se concluye que Peak Plus® es una alternativa efectiva a los insecticidas sintéticos en el control de C. cerasi

Polvos de especias aromáticas para el control del gorgojo del maiz, Sitophilus zeamais Motschulsky, en trigo almacenado

The maize weevil, Sitophilus zeamais Motschulsky, is considered one of the most important pests of stored grains. Plant powders from nine seasoning spices were tested in the laboratory to control S. zeamais at 0,5, 1, 2 and 4% (w/w). The variables evaluated were mortality and emergence (F1) of adult insects, grain weight loss and grain germination. The repellent and fumigant effects were evaluated at concentrations of 0.5, 1, 2 and 4%; the experimental design was completely randomized, with four replicates, and the group of treatments was repeated three times. The highest mortality percentages were obtained with Piper nigrum L. at 1% (83.4%), 2% (97.6%) and 4% (100%). The lowest adult insect emergence was obtained with the same treatments more Capsicum annuum var. longum Sendtn., Cinnamomum zeylanicum Blume and Pimpinella anisum L. at 4% (w/w). No significant differences were recorded as regards grain weight loss and germination. All the plant powders tested had a repellent effect on Sitophilus zeamais and no fumigant effect was recorded.El gorgojo del maíz Sitophilus zeamais Motschulsky,es considerado una de las plagas mas importantes de productos almacenados. Se evaluaron, en laboratorio, polvos vegetales provenientes de nueve especias condimentarias para el control de S. zeamais en concentraciones de 0,5; 1; 2 y 4%. Las variables evaluadas fueron mortalidad y emergencia (F1) de adultos y pérdida de peso y germinación del grano. También se evaluó el efecto repelente y fumigante a las concentraciones de 0,5; 1 y 2%. El diseño experimental fue completamente al azar, los tratamientos tuvieron cuatro repeticiones y el grupo de tratamientos fue repetido tres veces. Las mayores mortalidades se obtuvieron con Piper nigrum L. a 1% (83,4%), 2% (97,6%) y 4% (100%). Las menores emergencias de insectos adultos se obtuvieron en los mismos tratamientos más Capsicum annuum var. Longum Sendtn., Cinnamomum zeylanicum Blime y Pimpinella anisum L. al 4% (p/p). La pérdida de peso y germinación de granos no registraron diferencia significativa. Todos los polvos vegetales fueron repelentes para Sitophilus zeamais y ninguno tuvo efecto fumigante

Polvos de especias aromáticas para el control del gorgojo del maiz, Sitophilus zeamais Motschulsky, en trigo almacenado.

El gorgojo del maíz Sitophilus zeamais Motschulsky, es considerado una de las plagas mas importantes de productos almacenados. Se evaluaron, en laboratorio, polvos vegetales provenientes de nueve especias condimentarias para el control de S. zeamais en concentraciones de 0,5; 1; 2 y 4%. Las variables evaluadas fueron mortalidad y emergencia (F1) de adultos y pérdida de peso y germinación del grano. También se evaluó el efecto repelente y fumigante a las concentraciones de 0,5; 1 y 2%. El diseño experimental fue completamente al azar, los tratamientos tuvieron cuatro repeticiones y el grupo de tratamientos fue repetido tres veces. Las mayores mortalidades se obtuvieron con Piper nigrum L. a 1% (83,4%), 2% (97,6%) y 4% (100%). Las menores emergencias de insectos adultos se obtuvieron en los mismos tratamientos más Capsicum annuum var. Longum Sendtn., Cinnamomun zeylanicum Blime y Pimpinella anisum L. al 4% (p/p). La pérdida de peso y germinación de granos no registraron diferencia significativa. Todos los polvos vegetales fueron repelentes para Sitophilus zeamais y ninguno tuvo efecto fumigante

Propiedades Insecticidas del Polvo de Peumus boldus Molina Solo y en Mezcla con Cal contra Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)

The insecticidal properties of boldus ( Peumus boldus Molina) powder used alone and mixed with lime against adults of maize weevil ( Sitophilus zeamais Motschulsky) were evaluated under laboratory conditions. Additionally, aeration effects (presence or absence) and temperature (room temperature vs. 3 ºC) on insecticidal properties were studied over time. A mortality rate of 100% was observed at 20 g kg-1 (w/w) of P. boldus powder when used alone and mixed with lime in proportions of 50:50, 60:40, and 80:20. The 50% lethal concentration (LC50) for all treatments was < 5 g kg-1, while LC90 was 11 g kg-1. Mixing corn grains with different insecticidal treatments did not affect maize germination. Temperature and aeration did not influence mortality of maize weevil adults. When the boldus powder was mixed with the infested maize 24 h before grinding, the toxicity to the parental adults and emergence of F1 adults with respect to the untreated control was 100 and 0%, respectively. The results were not satisfactory when boldus powder was stored during 30, 60, and 90 d and then mixed with the infested maize. Boldus foliage toxicity was high 24 h after grinding, but decreased significantly over time.Se evaluaron las propiedades insecticidas del polvo de boldo ( Peumus boldus Molina), solo y en mezcla con cal, bajo condiciones de laboratorio. Adicionalmente, se evaluó el efecto de la aeración (presencia vs. ausencia) y de la temperatura (temperatura ambiente vs. 3 ºC) sobre la mortalidad y emergencia de adultos de la F1. La concentración de 20 g kg-1 (p/p) del polvo de boldo ya sea solo o en combinación con cal en las proporciones de 50:50, 60:40 y 80:20 mostraron 100% de mortalidad. La concentración letal 50% (CL50), en todos los tratamientos fue menor a 5 g kg-1 (p/p) mientras que la CL90 no superó 11 g kg-1 (p/p). La mezcla del polvo con los granos de maíz tanto solo como en mezcla con cal no afectó la germinación. La temperatura y la aeración no afectaron la mortalidad de los adultos parentales ni la emergencia de adultos de la F1. Cuando se mezcló el maíz con el polvo de boldo molido 24 h antes de la infestación con adultos, la mortalidad de los adultos parentales y la emergencia de adultos de la F1 fue de 100 y de 0%, respectivamente. Los resultados no fueron satisfactorios cuando el polvo de boldo almacenado durante 30, 60 y 90 d fue mezclado con el maíz infestado. La toxicidad del follaje de boldo es alta 24 h después de pulverizarse; si el tiempo es mayor, la toxicidad declina significativamente

Variación anual de las propiedades insecticidas de Peumus boldus sobre Sitophilus zeamais Annual variation of insecticide properties of Peumus boldus on Sitophilus zeamais

El objetivo del presente trabajo fue determinar la variación anual en las propiedades insecticidas de Peumus boldus Molina, en el control de Sitophilus zeamais Motschulsky, bajo condiciones de laboratorio. El polvo de hojas de P. boldus se evaluó durante 12 meses, en concentraciones de 0,5, 1 y 2% (p/p). Se evaluaron 36 tratamientos con tres repeticiones, en un diseño experimental completamente al azar, con un arreglo factorial. Se determinó el porcentaje de mortalidad y emergencia de insectos adultos e inmaduros y pérdida de peso y germinación del grano. La mayor mortalidad se obtuvo en los meses de agosto y septiembre de 2003, para las tres concentraciones con un 100%, mientras que la menor fue en mayo de 2003, cuando solo la concentración de 2% fue próxima a 100% de mortalidad. La menor emergencia de insectos adultos y pérdida de peso se obtuvieron en los mismos tratamientos. El efecto sobre estados inmaduros fue menor que contra adultos, y la germinación de los granos de maíz fue afectada por los polvos de P. boldus. Las propiedades insecticidas del polvo de hojas de P. boldus no son estables durante el año, Mayo es el mes con la menor eficacia insecticida, y la germinación de las semillas se ve afectada por el polvo.<br>The objective of this work was to determine the annual variation of Peumus boldus Molina insecticidal properties for the control of Sitophilus zeamais Motschulsky, under laboratory conditions. The powder of P. boldus leaves was evaluated, during 12 months, in 0.5, 1, and 2% (w/w) concentrations. Thirty-six treatments, with three replications, were evaluated in a completely randomized experimental design, with a factorial arrangement. Evaluations were made for adult and immature insect percentage mortality and emergence, grain weight loss and seed germination. The greatest mortality was obtained in August and September 2003, in the three concentrations with 100%, and the lowest mortality was registered in May 2003, when only 2% (w/w) reached almost 100% mortality. The lowest adult insect emergence and weight loss were obtained in the same treatments. The effect on immature stages was lower than on adults; and grain germination was affected by P. boldus powders. Insecticidal properties of P. boldus leaves powder are not stable during the year; May is the month with lesser insecticide efficacy; and the powder affects grain germination