Experimental study on the efficiency of different types of traps and baits for harvesting Macrobrachium amazonicum (Heller, 1862

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Bianca Bentes

2014-10-01

Full Text Available Macrobrachium amazonicum is a freshwater prawn endemic to South America with wide distribution in Brazilian Amazon rivers. In estuary and freshwater streams of the Pará State, they are captured with different types of traps locally know matapi. This study evaluated the efficiency of traps of different sizes (large, medium and small and baits (babassu coconut and fish for sampling this shrimp. Samplings were conducted with 24 traps with different treatments (trap size and bait. We captured 909 specimens. Higher mean catches were observed in traps baited with babassu coconut. Interactions between babassu coconut bait and medium matapi (BM-M, and fish bait and large matapi (FISH-L were significant. Carapace length (CL varied significantly between sites (F = 12.74, p < 0.01. The total maximum length was13.65 cm. Medium traps baited with babassu coconut were the most successful in the tested combinations, however, there was a clear correlation between size trap and size of shrimp, for both body weight and carapace length.

Management strategy evaluation of pheromone-baited trapping techniques to improve management of invasive sea lamprey

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Dawson, Heather; Jones, Michael L.; Irwin, Brian J.; Johnson, Nicholas; Wagner, Michael C.; Szymanski, Melissa

2016-01-01

We applied a management strategy evaluation (MSE) model to examine the potential cost-effectiveness of using pheromone-baited trapping along with conventional lampricide treatment to manage invasive sea lamprey. Four pheromone-baited trapping strategies were modeled: (1) stream activation wherein pheromone was applied to existing traps to achieve 10−12 mol/L in-stream concentration, (2) stream activation plus two additional traps downstream with pheromone applied at 2.5 mg/hr (reverse-intercept approach), (3) trap activation wherein pheromone was applied at 10 mg/hr to existing traps, and (4) trap activation and reverse-intercept approach. Each new strategy was applied, with remaining funds applied to conventional lampricide control. Simulating deployment of these hybrid strategies on fourteen Lake Michigan streams resulted in increases of 17 and 11% (strategies 1 and 2) and decreases of 4 and 7% (strategies 3 and 4) of the lakewide mean abundance of adult sea lamprey relative to status quo. MSE revealed performance targets for trap efficacy to guide additional research because results indicate that combining lampricides and high efficacy trapping technologies can reduce sea lamprey abundance on average without increasing control costs.

Gypsy moth (Lepidoptera: Lymantriidae) flight behavior and phenology based on field-deployed automated pheromone-baited traps

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Patrick C. Tobin; Kenneth T. Klein; Donna S. Leonard

2009-01-01

Populations of the gypsy moth, Lymantria dispar (L.), are extensively monitored in the United States through the use of pheromone-baited traps.We report on use of automated pheromone-baited traps that use a recording sensor and data logger to record the unique date-time stamp of males as they enter the trap.We deployed a total of 352 automated traps...

Heteroptera attracted to butterfly traps baited with fish or shrimp carrion

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Records of Heteroptera collected at butterfly traps baited with fish or shrimp carrion during collecting trips to Bolivia, Brazil, Colombia, Ecuador, and Peru are presented. Traps consisted of a cylinder of net fabric (about 35 cm diam, 75 cm length) attached on the top and bottom to square pieces ...

Factors Influencing Male Plutella xylostella (Lepidoptera: Plutellidae) Capture Rates in Sex Pheromone-Baited Traps on Canola in Western Canada.

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Miluch, C E; Dosdall, L M; Evenden, M L

2014-12-01

Optimization of male moth trapping rates in sex pheromone-baited traps plays a key role in managing Plutella xylostella (L.). We investigated various ways to increase the attractiveness of pheromone-baited traps to P. xylostella in canola agroecosystems in AB, Canada. Factors tested included pheromone blend and dose, addition of a green leaf volatile to the pheromone at different times during the season, lure type, trap color, and height. The industry standard dose of 100 μg of pheromone (four-component blend) per lure (ConTech Enterprises Inc., Delta, British Columbia [BC], Canada) captured the most moths in the two lure types tested. Traps baited with pheromone released from gray rubber septa captured more males than those baited with red rubber septa. Traps baited with lures in which Z11-16: Ac is the main component attracted significantly more moths than those in which Z11-16: Ald is the main component. The addition of the green leaf volatile, (Z)-3-hexenyl acetate, to pheromone at a range of doses, did not increase moth capture at any point during the canola growing season. Unpainted white traps captured significantly more male moths than pheromone-baited traps that were painted yellow. Trap height had no significant effect on moth capture. Recommendations for monitoring P. xylostella in canola agroecosystems of western Canada include using a pheromone blend with Z11-16: Ac as the main component released from gray rubber septa at a dose of 100 μg. © 2014 Entomological Society of America.

Residual CO2 trapping in Indiana limestone.

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El-Maghraby, Rehab M; Blunt, Martin J

2013-01-02

We performed core flooding experiments on Indiana limestone using the porous plate method to measure the amount of trapped CO(2) at a temperature of 50 °C and two pressures: 4.2 and 9 MPa. Brine was mixed with CO(2) for equilibration, then the mixture was circulated through a sacrificial core. Porosity and permeability tests conducted before and after 884 h of continuous core flooding confirmed negligible dissolution. A trapping curve for supercritical (sc)CO(2) in Indiana showing the relationship between the initial and residual CO(2) saturations was measured and compared with that of gaseous CO(2). The results were also compared with scCO(2) trapping in Berea sandstone at the same conditions. A scCO(2) residual trapping end point of 23.7% was observed, indicating slightly less trapping of scCO(2) in Indiana carbonates than in Berea sandstone. There is less trapping for gaseous CO(2) (end point of 18.8%). The system appears to be more water-wet under scCO(2) conditions, which is different from the trend observed in Berea; we hypothesize that this is due to the greater concentration of Ca(2+) in brine at higher pressure. Our work indicates that capillary trapping could contribute to the immobilization of CO(2) in carbonate aquifers.

Sampling gravid Culex quinquefasciatus (Diptera: Culicidae) in Tanzania with traps baited with synthetic oviposition pheromone and grass infusions

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Mboera, L.E.G.; Takken, W.; Mdira, K.Y.; Pickett, J.A.

2000-01-01

The effectiveness of traps baited with (5R,6S)-6-acetoxy-5-hexadecanolide (the synthetic oviposition pheromone) and grass infusions in sampling a population of gravid Culex quinquefasciatus Say was conducted in Muheza, Northeast Tanzania. A counterflow geometry (CFG) trap baited with pheromone and

Converting Mosquito Surveillance to Arbovirus Surveillance with Honey-Baited Nucleic Acid Preservation Cards.

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Flies, Emily J; Toi, Cheryl; Weinstein, Philip; Doggett, Stephen L; Williams, Craig R

2015-07-01

Spatially and temporally accurate information about infectious mosquito distribution allows for pre-emptive public health interventions that can reduce the burden of mosquito-borne infections on human populations. However, the labile nature of arboviruses, the low prevalence of infection in mosquitoes, the expensive labor costs for mosquito identification and sorting, and the specialized equipment required for arbovirus testing can obstruct arbovirus surveillance efforts. The recently developed techniques of testing mosquito expectorate using honey-baited nucleic acid preservation cards or sugar bait stations allows a sensitive method of testing for infectious, rather than infected, mosquito vectors. Here we report the results from the first large-scale incorporation of honey-baited cards into an existing mosquito surveillance program. During 4 months of the peak virus season (January-April, 2014) for a total of 577 trap nights, we set CO2-baited encephalitis vector survey (EVS) light traps at 88 locations in South Australia. The collection container for the EVS trap was modified to allow for the placement of a honey-baited nucleic acid preservation card (FTA™ card) inside. After collection, mosquitoes were maintained in a humid environment and allowed access to the cards for 1 week. Cards were then analyzed for common endemic Australian arboviruses using a nested RT-PCR. Eighteen virus detections, including 11 Ross River virus, four Barmah Forest virus, and three Stratford virus (not previously reported from South Australia) were obtained. Our findings suggest that adding FTA cards to an existing mosquito surveillance program is a rapid and efficient way of detecting infectious mosquitoes with high spatial resolution.

Evaluation of Commercial and Field-Expedient Baited Traps for House Flies, Musca domestica L. (Diptera: Muscidae)

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2009-01-09

32212, U.S.A. Received 7 September 2008; Accepted 9 January 2009 ABSTRACT: A comparison of nine commercial baited fly traps on Florida dairy farms...baits relied on natural products such as fermented egg slurries (Willson and Mulla 1973) or combinations of such items as molasses, milk, yeast, grain...2006 on four dairy farms in Gilchrist and Alachua counties, FL. Traps were placed near the calf pens on three of the farms and by the commodity

Influence of Trap Height and Bait Type on Abundance and Species Diversity of Cerambycid Beetles Captured in Forests of East-Central Illinois.

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Schmeelk, Thomas C; Millar, Jocelyn G; Hanks, Lawrence M

2016-08-01

We assessed how height of panel traps above the forest floor, and the type of trap bait used, influenced the abundance and diversity of cerambycid beetles caught in forested areas of east-central Illinois. Panel traps were suspended from branches of hardwood trees at three heights above the ground: understory (∼1.5 m), lower canopy (∼6 m), and midcanopy (∼12 m). Traps were baited with either a multispecies blend of synthesized cerambycid pheromones or a fermenting bait mixture. Traps captured a total of 848 beetles of 50 species in the cerambycid subfamilies Cerambycinae, Lamiinae, Lepturinae, and Parandrinae, and one species in the closely related family Disteniidae. The species caught in highest numbers was the cerambycine Anelaphus pumilus (Newman), represented by 349 specimens. The 17 most abundant species (mean ± 1 SD: 45 ± 80 specimens per species) included 12 cerambycine and five lamiine species. Of these most abundant species, 13 (77%) were attracted to traps baited with the pheromone blend. Only the cerambycine Eburia quadrigeminata (Say) was attracted by the fermenting bait. Three species were captured primarily in understory traps, and another five species primarily in midcanopy traps. Variation among cerambycid species in their vertical distribution in forests accounted for similar overall abundances and species richness across trap height treatments. These findings suggest that trapping surveys of native communities of cerambycids, and quarantine surveillance for newly introduced exotic species, would be optimized by including a variety of trap baits and distributing traps across vertical strata of forests. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

There is no magic fruit fly trap: multiple biological factors influence the response of adult Anastrepha ludens and Anastrepha obliqua (Diptera: Tephritidae) individuals to MultiLure traps baited with BioLure or NuLure.

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Díaz-Fleischer, Francisco; Arredondo, José; Flores, Salvador; Montoya, Pablo; Aluja, Martín

2009-02-01

Field-cage experiments were performed to determine the effectiveness of MultiLure traps (Better World MFG Inc., Fresno, CA) baited with NuLure (Miller Chemical and Fertilizer Corp., Hanover, PA) or BioLure (Suterra LLC, Inc., Bend, OR) in capturing individually marked Mexican fruit fly, Anastrepha ludens (Loew), and West Indian fruit fly, Anastrepha obliqua (Macquart) (Diptera: Tephritidae), of both sexes. Experimental treatments involved wild and laboratory-reared flies of varying ages (2-4 and 15-18 d) and dietary histories (sugar only, open fruit, open fruit plus chicken feces, and hydrolyzed protein mixed with sugar). Data were divided into two parts: total captures over a 24-h period and trap visits/landings, entrances into interior of trap ,and effective captures (i.e., drowning in liquid bait or water) over a 5-h detailed observation period (0600-1100 hours). The response to the two baits varied by fly species, gender, physiological state, age, and strain. Importantly, there were several highly significant interactions among these factors, underlining the complex nature of the response. The two baits differed in attractiveness for A. obliqua but not A. ludens. The effect of strain (wild versus laboratory flies) was significant for A. ludens but not A. obliqua. For effect of dietary history, adults of both species, irrespective of sex, were significantly less responsive to both baits when fed on a mixture of protein and sugar when compared with adults fed the other diets. Finally, we confirmed previous observations indicating that McPhail-type traps are quite inefficient. Considering the total 24-h fly tenure in the cage, and independent of bait treatment and fly type (i.e., strain, adult diet, gender and age), of a total of 2,880 A. obliqua and 2,880 A. ludens adults released into the field cages over the entire study (15 replicates), only 564 (19.6%) and 174 (6%) individuals, respectively, were effectively caught. When only considering the 5-h detailed

Efficiency of box-traps and leg-hold traps with several bait types for capturing small carnivores (Mammalia in a disturbed area of Southeastern Brazil

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Fernanda Michalski

2007-03-01

Full Text Available Capturing small carnivores is often necessary for obtaining key ecological data. We compared the efficiency of box and leg-hold traps, using live and dead bait, to capture six carnivore species (Herpailurus yagouaroundi (É. Geoffroyi, 1803, Leopardus tigrinus (Schreber, 1775, Nasua nasua (Linnaeus, 1766, Cerdocyon thous (Linnaeus, 1766, Eira barbara (Linnaeus, 1758, and Galictis cuja (Molina, 1782. The use of leg-hold traps significantly increased the capture rate of carnivores (5.77% and non-target species (non-carnivores, 11.54%. Dead bait significantly attracted more non-carnivores than carnivores and live bait was more efficient for capturing carnivores (2.56% than non-carnivores (0.77%. Both box and leg-hold traps caused some minor injuries (swelling and claw loss. We provide recommendations for the ethical use of these trap and bait types. Rev. Biol. Trop. 55 (1: 315-320. Epub 2007 March. 31.La captura de pequeños carnívoros es una práctica común para obtener datos ecológicos. Comparamos la eficiencia de cepos (trampas acolchadas y trampas tomahawk para capturar seis especies carnívoras (Herpailurus yagouaroundi (É. Geoffroyi, 1803, Leopardus tigrinus (Schreber, 1775, Nasua nasua (Linnaeus, 1766, Cerdocyon thous (Linnaeus, 1766, Eira barbara (Linnaeus, 1758, and Galictis cuja (Molina, 1782, utilizando carnadas vivas y muertas. Con los cepos se incrementó significativamente la tasa de captura de carnívoros (5.77% y otros mamíferos (no-carnívoros, 11.54%. La carnada muerta atrajo significativamente mas no-carnívoros que carnívoros, mientras que con la carnada viva se capturaron más carnívoros (2.56% vs 0.77% no-carnívoros. Ambos tipos de trampas; cepos y tomahawk, causaron algunas pequeñas lastimaduras (inflamación y pérdida de garras. Hacemos algunas recomendaciones para el uso ético de este tipo de trampas y cebos.

Trapping for invasive crayfish: comparisons of efficacy and selectivity of baited traps versus novel artificial refuge traps

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Green Nicky

2018-01-01

Full Text Available Non-native crayfish can dominate the invertebrate biomass of invaded freshwaters, with their high ecological impacts resulting in their populations being controlled by numerous methods, especially trapping. Although baited funnel traps (BTs are commonly used, they tend to be selective in mainly catching large-bodied males. Here, the efficacy and selectivity of BTs were tested against an alternative trapping method based on artificial refuges (ARTs that comprised of a metal base with several tubes (refuges attached. The target species was signal crayfish Pacifastacus leniusculus in an upland river in southwest England. Trapping was completed in April to October over two consecutive years. In total, 5897 crayfish were captured, with 87% captured in ARTs. Comparison of the catch per unit effort (CPUE between the trapping methods in the same 24 hour periods revealed significantly higher CPUE in ARTs than of BTs. ARTs fished for 6 consecutive days had higher catches than both methods over 24 hours. Whilst catches in BTs were significantly dominated by males (1.49M:1F, the sex ratio of catches in ARTs was 0.99M:1F. The mean carapace length of crayfish was also significantly larger in BTs (43.2 ± 0.6 mm than in ARTs (33.6 ± 0.2 mm. Thus, ARTs had higher CPUE over 24 hour and 6 day periods versus BTs and also captured a greater proportion of smaller and female individuals. These results indicate that when trapping methods are deployed for managing invasions, the use of ARTs removes substantial numbers of crayfish of both sexes and of varying body sizes.

Monitoring oriental fruit moth (Lepidoptera: Tortricidae) with sticky traps baited with terpinyl acetate and sex pheromone

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Studies in Argentina and Chile during 2010-11 evaluated a new trap (Ajar) for monitoring the oriental fruit moth, Grapholita molesta (Busck). The Ajar trap was delta-shaped with a jar filled with a terpinyl acetate plus brown sugar bait attached to the bottom center of the trap. The screened lid of ...

Field evaluation of synthetic lure (3-methyl-1-butanol) when compared to non odor-baited control in capturing Anopheles mosquitoes in varying land-use sites in Madagascar.

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Zohdy, Sarah; Derfus, Kristin; Andrianjafy, Mbolatiana Tovo; Wright, Patricia C; Gillespie, Thomas R

2015-03-07

Malaria is the 4(th) largest cause of mortality in Madagascar. To better understand malaria transmission dynamics, it is crucial to map the distribution of the malaria vectors, mosquitoes belonging to the genus Anopheles. To do so, it is important to have a strong Anopheles-specific lure to ensure the maximum number of captures. Previous studies have isolated volatiles from the human skin microbiota and found the compound 3-methyl-1-butanol to be the most attractive to the malaria mosquito, Anopheles gambiae, in a laboratory setting; and recommended 3-methyl-1-butanol as a compound to increase An. gambiae captures in the field. To date, this compound's ability to lure wild mosquitoes in differing land-use settings has not been tested. In this study, we evaluate the role of the synthetic compound, 3-methyl-1-butanol in combination with field produced CO(2) in attracting Anopheles mosquitoes in varying land-use sites in Madagascar. CDC miniature light traps in combination with field produced CO(2) were deployed in and around six villages near Ranomafana National Park, Madagascar. To test the role of 3-methyl-1-butanol in luring Anopheles mosquitoes, two traps were set in each land-use site (village, agricultural sites, and forested habitats affiliated with each village). One was baited with the synthetic odor and the other was kept as a non-baited control. While 3-methyl-1-butanol baited traps did capture An. gambiae s.l. in this study, we did not find traps baited with synthetic 3-methyl-1-butanol to be more successful in capturing Anopheles mosquitoes, (including Anopheles gambiae s.l.) than the non odor-baited control traps in any of the land-use sites examined; however, regardless of odor bait, trapping near livestock pens resulted in the capture of significantly more Anopheles specimens. A strong synthetic lure in combination with insecticide has great potential as a mosquito control. Our findings suggest that trapping mosquitoes near livestock in malaria

Tempo-Spatial Dynamics of Adult Plum Curculio (Coleoptera: Curculionidae) Based on Semiochemical-Baited Trap Captures in Blueberries.

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Hernandez-Cumplido, Johnattan; Leskey, Tracy C; Holdcraft, Robert; Zaman, Faruque U; Hahn, Noel G; Rodriguez-Saona, Cesar

2017-06-01

Plum curculio, Conotrachelus nenuphar (Herbst), has become an important pest of highbush blueberries in the northeastern United States. Here, we conducted experiments in 2010-2013 to compare the efficacy of semiochemical-baited traps for C. nenuphar versus conventional (beating cloth) sampling methods in blueberries, and to understand the seasonal abundance and distribution of C. nenuphar adults within and among blueberry fields using these traps. Black pyramid traps baited with the C. nenuphar aggregation pheromone grandisoic acid and the fruit volatile benzaldehyde caught three to four times more adults than unbaited traps without causing an increase in injury to berries in neighboring bushes. Numbers of adult weevils caught in traps correlated with those on bushes (beating cloth samples), indicating that trap counts can predict C. nenuphar abundance in the field. Early in the season, traps placed 20 m from field edges near a forest caught higher C. nenuphar numbers than traps placed at farther distances, suggesting movement of overwintered weevils from outside fields. Using a trapping network across multiple fields in an organic farm, we found evidence of C. nenuphar aggregation in "hotspots"; early in the season, C. nenuphar numbers in traps were higher in the middle of fields, and there was a correlation between these numbers and distance from the forest in 2013 but not in 2012. These results show that semiochemical-baited traps are effective in capturing C. nenuphar adults in blueberries, and that these traps should be placed in the interior of fields preferably, but not exclusively, near wooded habitats to maximize their efficacy. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Influence of trap construction on mosquito capture

Czech Academy of Sciences Publication Activity Database

Šebesta, Oldřich; Peško, Juraj; Gelbič, Ivan

2012-01-01

Roč. 6, č. 2 (2012), s. 209-215 ISSN 1934-7391 R&D Projects: GA MŠk 2B08003 Institutional research plan: CEZ:AV0Z50070508 Institutional support: RVO:68081766 ; RVO:60077344 Keywords : CDC miniature light traps * baited lard-can traps * mosquitoes Subject RIV: EG - Zoology

Trapping of the malaria vector Anopheles gambiae with odour-baited MM-X traps in semi-field conditions in western Kenya

NARCIS (Netherlands)

Njiru, B.N.; Mukabana, W.R.; Takken, W.; Knols, B.G.J.

2006-01-01

Background - The successful development of odour-baited trapping systems for mosquitoes depends on the identification of behaviourally active semiochemicals, besides the design and operating principles of such devices. A large variety of 'attractants' has been identified in laboratory

Effects of carbaryl-bran bait on trap catch and seed predation by ground beetles (Coleoptera: Carabidae).

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Fielding, Dennis J; DeFoliart, Linda S; Hagerty, Aaron M

2013-04-01

Carbaryl-bran bait is effective against grasshoppers without many impacts on nontarget organisms, but ground beetles (Coleoptera: Carabidae) may be susceptible to these baits. Carabids are beneficial in agricultural settings as predators of insect pests and weed seeds. Carabid species and their consumption of weed seeds have not been previously studied in agricultural settings in Alaska. This study examined the effect of grasshopper bran bait on carabid activity-density, as measured by pitfall trap catches, and subsequent predation by invertebrates of seeds of three species of weed. Data were collected in fallow fields in agricultural landscape in the interior of Alaska, near Delta Junction, in 2008 and 2010. Bait applications reduced ground beetle activity-density by over half in each of 2 yr of bait applications. Seed predation was generally low overall (1-10%/wk) and not strongly affected by the bait application, but predation of lambsquarters (Chenopodium album L.) seed was lower on treated plots in 1 yr (340 seeds recovered versus 317 seeds, on treated versus untreated plots, respectively). Predation of dandelion (Taraxacum officinale G. H. Weber ex Wiggers) seeds was correlated with ground beetle activity-density in 1 yr, and predation of dragonhead mint (Dracocephalum parvifolium Nutt.) seed in the other year. We conclude that applications of carbaryl-bran bait for control of grasshoppers will have only a small, temporary effect on weed seed populations in high-latitude agricultural ecosystems.

A pheromone-baited trap for monitoring the Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae).

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Mullen, M A.; Dowdy, A K.

2001-07-01

A pheromone-baited trap was developed to monitor the Indian meal moth in grocery stores and similar areas where visible traps are not desirable. The trap can be used under shelves and against walls. As a shelf mount, the trap is in close proximity to the food packages and may capture emerging insects before they mate. The trap can also be used as a hanging trap similar to the Pherocon II. When used as a shelf or wall mount, it was as effective as the Pherocon II, but when used as a hanging trap significantly fewer insects were captured.

Laboratory and Field Age of Aqueous Grape Juice Bait and Capture of Zaprionus indianus (Diptera: Drosophilidae).

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Epsky, Nancy D; Gill, Micah A

2017-06-01

Volatile chemicals produced by actively fermenting aqueous grape juice bait have been found to be highly attractive to the African fig fly, Zaprionus indianus Gupta. This is a highly dynamic system and time period of fermentation is an important factor in bait efficacy. A series of field tests were conducted that evaluated effects of laboratory versus field fermentation and sampling period (days after placement [DAP]) on bait effectiveness as the first step in identifying the chemicals responsible for attraction. Tests of traps with bait that had been aged in the laboratory for 0, 3, 6, and 9 d and then sampled 3 DAP found higher capture in traps with 0- and 3-d-old baits than in traps with 6- or 9-d-old baits. To further define the time period that produced the most attractive baits, a subsequent test evaluated baits aged for 0, 2, 4, and 6 d in the laboratory and sampled after 1-4 DAP, with traps sampled and bait discarded at the end of each DAP period. The highest capture was in traps with 4-d-old bait sampled 1 DAP, with the second best capture in traps with 0-d-old bait sampled 3 DAP. However, there tended to be fewer flies as DAP increased, indicating potential loss of identifiable flies owing to decomposition in the actively fermenting solutions. When traps were sampled and bait recycled daily, the highest capture was in 2- and 4-d-old baits sampled 1 DAP and in 0-d-old baits sampled 2-4 DAP. Similar patterns were observed for capture of nontarget drosophilids. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

Trapping Douglas-fir beetle (Dendroctonus pseudotsugae) with pheromone baited multiple-funnel traps does not reduce Douglas-fir (Pseudotsuga menziesii) mortality

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R.A. Progar; N. Sturdevant; M.J. Rinella

2010-01-01

Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) (DFB) causes considerable mortality to Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in western North American forests. We evaluated the use of semiochemical-baited multiple-funnel traps for the protection of small, high-value stands of trees, such as those occurring...

Forest tent caterpillar, Malacosoma disstria (Lepidoptera: Lasiocampidae mate-finding behavior is greatest at intermediate population densities: Implications for interpretation of moth capture in pheromone-baited traps.

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Maya L. Evenden

2015-07-01

Full Text Available The forest tent caterpillar, Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae is a native forest defoliator with a broad geographic range in North America. Forest tent caterpillars experience cyclical population changes and at high densities, repeated defoliation can cause reduced tree growth and tree mortality. Pheromone-based monitoring of forest tent caterpillar moths can provide information on spatial and temporal patterns of incipient outbreaks. Pheromone-baited trap capture of male moths correlates to the number of eggs and pupae in a population but this relationship breaks down at high population densities, when moth trap capture declines. The objective of the current study is to understand the mechanisms that reduce trap capture at high population densities. We tested two different hypotheses: 1 at high population densities, male moth orientation to pheromone sources is reduced due to competition for pheromone plumes; and 2 moths from high density populations will be in poor condition and less likely to conduct mate-finding behaviors than moths from low density populations. A field study showed non-linear effects of density on male moth capture in female-baited traps. The number of males captured increased up to an intermediate density level and declined at the highest densities. Field cage studies showed that female moth density affected male moth orientation to female-baited traps, as more males were recaptured at low than high female densities. There was no effect of male density on the proportion of males that oriented to female-baited traps. Moth condition was manipulated by varying larval food quantity. Although feeding regimes affected the moth condition (size, there was no evidence of an effect of condition on mate finding or close range mating behavior. In the field, it is likely that competition for pheromone plumes at high female densities during population outbreaks reduces the efficacy of pheromone-baited monitoring

Is the capture success of orchid bees (Hymenoptera, Apoidea influenced by different baited trap designs? A case study from southern Brazil

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Nicolle Veiga Sydney

2015-03-01

Full Text Available Orchid bees are increasingly applied on Neotropical biomonitoring and bioindication studies due to the relative easiness of sampling and identification when compared to other bee groups. A considerable number of orchid bee community studies have been adopting baited traps as a sampling method, especially for replication purposes. However, the trap attributes are variable, and hitherto no evaluation of different designs was carried out. Here, five attributes of baited traps were tested: trap volume, number of entrance holes, presence of landing platform, kind of landing platform, and fixation content. We use Mann-Whitney tests to access differences in richness and abundance capture rates for each trap design. We found that volume, number of entrance holes, and fixation content do not influence orchid bees capture. However, the design without landing platforms had a significantly higher capture rate for richness when compared with sanded landing platforms. On the other hand, analyzing the kind of landing platform, we detected a significantly higher richness and abundance for the trap with landing platforms glued with sand. Despite the fact that the effects of different designs tested here were very punctual, we consider that results from samples taken with different baited trap designs are comparable. Some adjustments on trap design can be done according to the particularities of future studies.

Time Spent by Calliphora Spp. Blowflies on Standard Traps Baited with Liver and Ammonia

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Florica Morariu

2010-10-01

Full Text Available The larvae of blowflies from the Calliphoridae family cause fly strikes in sheep and other species of economic importance. Impaired wool, decrease of ewe fertility, and even death can occur in heavy infestations. This paper describes the Calliphora spp. blowflies’ behavior on and around a trap baited with liver and ammonia before they entered in. More than half of Calliphora spp. blowflies (50.88% stayed a medium time (eight to fourteen seconds on the standard trap, while only 1.79% of them spent a longer time (26 to 30 seconds before entering the trap.

Comparison of male and female emerald ash borer (Coleoptera: Buprestidae) responses to phoebe oil and (Z)-3-hexanol lures in light green prism traps

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Gary G. Grant; Therese M. Poland; Tina Ciaramitaro; D. Barry Lyons; Gene C. Jones

2011-01-01

We conducted trapping experiments for the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in Michigan, USA, and Ontario, Canada, to compare unbaited light green sticky prism traps with traps baited with phoebe oil, (Z)-3-hexenol (Z3-6:OH), or blends of other green leaf volatiles (GLVs) with Z3-6:OH. Traps were placed in the...

Orchid bee baits attracting bees of the genus Megalopta (Hymenoptera, Halictidae) in Bauru region, São Paulo, Brazil: abundance, seasonality, and the importance of odors for dim-light bees

OpenAIRE

Fátima R. N. Knoll; Leandro M. Santos

2012-01-01

Nocturnal bees in the genus Megalopta Smith, 1853 are generally collected using artificial light sources. However, between 1993 and 2000, a total of 946 females (no males were captured) were captured using aromatic baits commonly used for orchid bees (Euglossini) in five localities in Bauru region, São Paulo, Brazil. Aromatic compounds used in bait traps were: benzyl acetate, eucalyptol, eugenol, skatole, methyl salicylate, and vanillin. The Megalopta species collected were: M. guimaraesi (71...

How much CO2 is trapped in carbonate minerals of a natural CO2 occurrence?

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Király, Csilla; Szabó, Zsuzsanna; Szamosfalvi, Ágnes; Cseresznyés, Dóra; Király, Edit; Szabó, Csaba; Falus, György

2017-04-01

Carbon Capture and Storage (CCS) is a transitional technology to decrease CO2 emissions from human fossil fuel usage and, therefore, to mitigate climate change. The most important criteria of a CO2 geological storage reservoir is that it must hold the injected CO2 for geological time scales without its significant seepage. The injected CO2 undergoes physical and chemical reactions in the reservoir rocks such as structural-stratigraphic, residual, dissolution or mineral trapping mechanisms. Among these, the safest is the mineral trapping, when carbonate minerals such as calcite, ankerite, siderite, dolomite and dawsonite build the CO2 into their crystal structures. The study of natural CO2 occurrences may help to understand the processes in CO2 reservoirs on geological time scales. This is the reason why the selected, the Mihályi-Répcelak natural CO2 occurrence as our research area, which is able to provide particular and highly significant information for the future of CO2 storage. The area is one of the best known CO2 fields in Central Europe. The main aim of this study is to estimate the amount of CO2 trapped in the mineral phase at Mihályi-Répcelak CO2 reservoirs. For gaining the suitable data, we apply petrographic, major and trace element (microprobe and LA-ICP-MS) and stable isotope analysis (mass spectrometry) and thermodynamic and kinetic geochemical models coded in PHREEQC. Rock and pore water compositions of the same formation, representing the pre-CO2 flooding stages of the Mihályi-Répcelak natural CO2 reservoirs are used in the models. Kinetic rate parameters are derived from the USGS report of Palandri and Kharaka (2004). The results of petrographic analysis show that a significant amount of dawsonite (NaAlCO3(OH)2, max. 16 m/m%) precipitated in the rock due to its reactions with CO2 which flooded the reservoir. This carbonate mineral alone traps about 10-30 kg/m3 of the reservoir rock from the CO2 at Mihályi-Répcelak area, which is an

Semi-field assessment of the BG-Malaria trap for monitoring the African malaria vector, Anopheles arabiensis.

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Elis P A Batista

Full Text Available Odour-baited technologies are increasingly considered for effective monitoring of mosquito populations and for the evaluation of vector control interventions. The BG-Malaria trap (BGM, which is an upside-down variant of the widely used BG-Sentinel trap (BGS, has been demonstrated to be effective to sample the Brazilian malaria vector, Anopheles darlingi. We evaluated the BGM as an improved method for sampling the African malaria vectors, Anopheles arabiensis. Experiments were conducted inside a large semi-field cage to compare trapping efficiencies of BGM and BGS traps, both baited with the synthetic attractant, Ifakara blend, supplemented with CO2. We then compared BGMs baited with either of four synthetic mosquito lures, Ifakara blend, Mbita blend, BG-lure or CO2, and an unbaited BGM. Lastly, we compared BGMs baited with the Ifakara blend dispensed via either nylon strips, BG cartridges (attractant-infused microcapsules encased in cylindrical plastic cartridge or BG sachets (attractant-infused microcapsules encased in plastic sachets. All tests were conducted between 6P.M. and 7A.M., with 200-600 laboratory-reared An. arabiensis released nightly in the test chamber. The median number of An. arabiensis caught by the BGM per night was 83, IQR:(73.5-97.75, demonstrating clear superiority over BGS (median catch = 32.5 (25.25-37.5. Compared to unbaited controls, BGMs baited with Mbita blend caught most mosquitoes (45 (29.5-70.25, followed by BGMs baited with CO2 (42.5 (27.5-64, Ifakara blend (31 (9.25-41.25 and BG lure (16 (4-22. BGM caught 51 (29.5-72.25 mosquitoes/night, when the attractants were dispensed using BG-Cartridges, compared to BG-Sachet (29.5 (24.75-40.5, and nylon strips (27 (19.25-38.25, in all cases being significantly superior to unbaited controls (p < 000.1. The findings demonstrate potential of the BGM as a sampling tool for African malaria vectors over the standard BGS trap. Its efficacy can be optimized by selecting

Pore-scale imaging of capillary trapped supercritical CO2 as controlled by water-wet vs. CO2-wet media and grain shapes

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Chaudhary, K.; Cardenas, M.; Wolfe, W. W.; Maisano, J. A.; Ketcham, R. A.; Bennett, P.

2013-12-01

The capillary trapping of supercritical CO2 (s-CO2) is postulated to comprise up to 90% of permanently trapped CO2 injected during geologic sequestration. Successive s-CO2/brine flooding experiments under reservoir conditions showed that water-wet rounded beads trapped 15% of injected s-CO2 both as clusters and as individual ganglia, whereas CO2¬-wet beads trapped only 2% of the injected s-CO2 as minute pockets in pore constrictions. Angular water-wet grains trapped 20% of the CO2 but flow was affected by preferential flow. Thus, capillary trapping is a viable mechanism for the permanent CO2 storage, but its success is constrained by the media wettability.

Capture of melon flies, Zeugodacus cucurbitae (Diptera: Tephritidae), in a food-baited Multilure trap: influence of distance, diet, and sex

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Many countries operate trapping programs to detect invasions of pestiferous fruit fly species (Diptera: Tephritidae). Surveillance relies heavily on traps baited with male lures, which, while powerful, have limited effectiveness, because (i) they are sex-specific and (ii) males of some species do no...

Enhanced attraction of Plutella xylostella (Lepidoptera: Plutellidae) to pheromone-baited traps with the addition of green leaf volatiles.

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Li, Pengyan; Zhu, Junwei; Qin, Yuchuan

2012-08-01

Diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is one of the most serious pests of Brassicaceae crops worldwide. Electrophysiological and behavioral responses of P. xylostella to green leaf volatiles (GLVs) alone or together with its female sex pheromone were investigated in laboratory and field. GLVs 1-hexanol and (Z)-3-hexen-1-ol elicited strong electroantennographic responses from unmated male and female P. xylostella, whereas (Z)-3-hexenyl acetate only produced a relatively weak response. The behavioral responses of unmated moths to GLVs were further tested in Y-tube olfactometer experiments. (E)-2-Hexenal, (Z)-3-hexen-1-ol, and (Z)-3-hexenyl acetate induced attraction of males, reaching up to 50%, significantly higher than the response to the unbaited control arm. In field experiments conducted in 2008 and 2009, significantly more moths were captured in traps baited with synthetic sex pheromone with either (Z)-3-hexenyl acetate alone or a blend of (Z)-3-hexenyl acetate, (Z)-3-hexen-1-ol, and (E)-2-hexenal compared with sex pheromone alone and other blend mixtures. These results demonstrated that GLVs could be used to enhance the attraction of P. xylostella males to sex pheromone-baited traps.

Evaluation of bait traps as a means to predict initial blow fly (Diptera: Calliphoridae) communities associated with decomposing swine remains in New Jersey, USA.

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Weidner, Lauren M; Gemmellaro, M Denise; Tomberlin, Jeffery K; Hamilton, George C

2017-09-01

Information about blow fly (Diptera: Calliphoridae) species distributions can be valuable for criminal investigations, with regards to determining movement of remains from one location to another and time of colonization estimates, making these data extremely useful. Past work has been conducted on initial species community structure across New Jersey, USA using traps baited with beef liver; however, if these same species frequent vertebrate carrion remains unclear. In order to evaluate these data, piglet carcasses were placed out once every two weeks for a year in New Brunswick, New Jersey, USA. The same methods were implemented as those used for traps baited with beef liver, with length of collections being based on ADD values. Seven calliphorid species, Calliphora vicina (Robineau-Desvoidy), Lucilia sericata (Meigen), Lucilia coeruleiviridis (Macquart), Phormia regina (Meigen), Pollenia pediculata Macquart, Pollenia rudis (F.) and Protophormia terraenovae (Robineau-Desvoidy) were collected from the carcasses. During this experiment L. sericata, L. coeruleiviridis and P. regina were the dominant adult blow flies captured, totaling 38.2%, 29.2% and 29.2% respectively of all adults caught. All three species colonized the carcasses as well, although not all were dominant colonizers. C. vicina was recorded ovipositing in December, while the piglet was submerged in approximately 5cm of snow. All species that totaled at least 1% of the total collection (adults captured and larvae reared) were the same across baited traps and carcasses. This study supports the use of beef liver baits for surveying forensically important blow flies and the application of such information to forensic investigations. Copyright © 2017 Elsevier B.V. All rights reserved.

Trapping of Rift Valley Fever (RVF vectors using Light Emitting Diode (LED CDC traps in two arboviral disease hot spots in Kenya

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Tchouassi David P

2012-05-01

Full Text Available Abstract Background Mosquitoes’ response to artificial lights including color has been exploited in trap designs for improved sampling of mosquito vectors. Earlier studies suggest that mosquitoes are attracted to specific wavelengths of light and thus the need to refine techniques to increase mosquito captures following the development of super-bright light-emitting diodes (LEDs which emit narrow wavelengths of light or very specific colors. Therefore, we investigated if LEDs can be effective substitutes for incandescent lamps used in CDC light traps for mosquito surveillance, and if so, determine the best color for attraction of important Rift Valley Fever (RFV vectors. Methods The efficiency of selected colored LED CDC light traps (red, green, blue, violet, combination of blue-green-red (BGR to sample RVF vectors was evaluated relative to incandescent light (as control in a CDC light trap in two RVF hotspots (Marigat and Ijara districts in Kenya. In field experiments, traps were baited with dry ice and captures evaluated for Aedes tricholabis, Ae. mcintoshi, Ae. ochraceus, Mansonia uniformis, Mn. africana and Culex pipiens, following Latin square design with days as replicates. Daily mosquito counts per treatment were analyzed using a generalized linear model with Negative Binomial error structure and log link using R. The incidence rate ratios (IRR that mosquito species chose other treatments instead of the control, were estimated. Results Seasonal preference of Ae.mcintoshi and Ae. ochraceus at Ijara was evident with a bias towards BGR and blue traps respectively in one trapping period but this pattern waned during another period at same site with significantly low numbers recorded in all colored traps except blue relative to the control. Overall results showed that higher captures of all species were recorded in control traps compared to the other LED traps (IRR  Conclusion Based on our trapping design and color, none of the LEDs

Influence of trap color and host volatiles on capture of the emerald ash borer (Coleoptera: Buprestidae).

Science.gov (United States)

Crook, Damon J; Khrimian, Ashot; Cossé, Allard; Fraser, Ivich; Mastro, Victor C

2012-04-01

Field trapping assays were conducted in 2009 and 2010 throughout western Michigan, to evaluate lures for adult emerald ash borer, A. planipennis Fairmaire (Coleoptera: Buprestidae). Several ash tree volatiles were tested on purple prism traps in 2009, and a dark green prism trap in 2010. In 2009, six bark oil distillate lure treatments were tested against manuka oil lures (used in 2008 by USDA APHIS PPQ emerald ash borer cooperative program). Purple traps baited with 80/20 (manuka/phoebe oil) significantly increased beetle catch compared with traps baited with manuka oil alone. In 2010 we monitored emerald ash borer attraction to dark green traps baited with six lure combinations of 80/20 (manuka/phoebe), manuka oil, and (3Z)-hexenol. Traps baited with manuka oil and (3Z)-hexenol caught significantly more male and total count insects than traps baited with manuka oil alone. Traps baited with manuka oil and (3Z)-hexenol did not catch more beetles when compared with traps baited with (3Z)-hexenol alone. When compared with unbaited green traps our results show that (3Z)-hexenol improved male catch significantly in only one of three field experiments using dark green traps. Dark green traps caught a high number of A. planipennis when unbaited while (3Z)-hexenol was seen to have a minimal (nonsignificant) trap catch effect at several different release rates. We hypothesize that the previously reported kairomonal attractancy of (3Z)-hexenol (for males) on light green traps is not as obvious here because of improved male attractancy to the darker green trap.

Chlorophyllin Bait Formulation and Exposure to Different Spectrum of Visible Light on the Reproduction of Infected/Uninfected Snail Lymnaea acuminata

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Navneet Kumar

2016-01-01

Full Text Available Fasciolosis is a waterborne disease, caused by Fasciola species. Snail Lymnaea acuminata is an intermediate host of these flukes. Control of snail population is major tool in reducing the incidences. Variation in light intensity and wavelength caused significant changes in reproduction pattern of snails. Maximum fecundity was noted with bait containing carbohydrate (starch, 468 ± 0.10/20 snails or amino acid (serine, 319 ± 0.29/20 snails as attractant. Sublethal feeding of chlorophyllin bait with starch or serine attractant to infected and uninfected snails caused significant reduction in fecundity, hatchability, and survivability. These significant changes are observed in snails exposed to different spectral band of visible light and sunlight. Maximum fecundity of 536 ± 2.0 and minimum of 89.3 ± 0.4 were noted in snails not fed with bait and exposed to sunlight and red spectral band, respectively. There was complete arrest in the fecundity of infected and uninfected snails and no survivability of uninfected snails after 48 h feeding with bait containing chlorophyllin + attractant. Minimum hatchability (9.25 ± 0.5 was noted in red light exposed, chlorophyllin + starch fed infected snails and hatching period of bait fed snails was prolonged. Conclusively, chlorophyllin bait and red light reduce reproduction capacity in snails.

Development of a Novel Trap for the Collection of Black Flies of the Simulium ochraceum Complex

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Rodríguez-Pérez, Mario A.; Adeleke, Monsuru A.; Burkett-Cadena, Nathan D.; Garza-Hernández, Javier A.; Reyes-Villanueva, Filiberto; Cupp, Eddie W.; Toé, Laurent; Salinas-Carmona, Mario C.; Rodríguez-Ramírez, Américo D.; Katholi, Charles R.; Unnasch, Thomas R.

2013-01-01

Background Human landing collections are currently the standard method for collecting onchocerciasis vectors in Africa and Latin America. As part of the efforts to develop a trap to replace human landing collections for the monitoring and surveillance of onchocerciasis transmission, comprehensive evaluations of several trap types were conducted to assess their ability to collect Simulium ochraceum sensu lato, one of the principal vectors of Onchocerca volvulus in Latin America. Methodology/Principal Findings Diverse trap designs with numerous modifications and bait variations were evaluated for their abilities to collect S. Ochraceum s.l. females. These traps targeted mostly host seeking flies. A novel trap dubbed the “Esperanza window trap” showed particular promise over other designs. When baited with CO2 and BG-lure (a synthetic blend of human odor components) a pair of Esperanza window traps collected numbers of S. Ochraceum s.l. females similar to those collected by a team of vector collectors. Conclusions/Significance The Esperanza window trap, when baited with chemical lures and CO2 can be used to collect epidemiologically significant numbers of Simulium ochraceum s.l., potentially serving as a replacement for human landing collections for evaluation of the transmission of O. volvulus. PMID:24116169

Selected beetle assemblages captured in pitfall traps baited with deer dung or meat in balsam fir and sugar maple forests of central Quebec.

Science.gov (United States)

Brousseau, Pierre-Marc; Cloutier, Conrad; Hébert, Christian

2010-08-01

Vertebrate dung and carrion are rich and strongly attractive resources for numerous beetles that are often closely linked to them. The presence and abundance of beetles exploiting such resources are influenced by various ecological factors including climate and forest cover vegetation. We studied selected assemblages of coprophilous and necrophagous beetles in Quebec along a 115-km north-south transect in three balsam fir (Abies balsamea (L.) Miller) forest sites and in a fourth forest site dominated by sugar maple (Acer saccharum Marshall), close to the southern fir site. Beetle abundance was estimated using a sampling design comprising replicated pitfall traps baited with red deer meat or dung in each site. A total of 8,511 beetles were caught and identified to family level, 95.7% of which belonged to families with known coprophilous or necrophagous behavior. Meat-baited pitfall traps caught nearly 15 times as many beetles as dung-baited traps. All Histeridae, Hydrophilidae, Scarabaeidae, and Silphidae were identified to species to examine specific diversity variation among sites. For the beetles caught in the meat-baited traps (majority of captures), decreases in abundance and species richness were observed from south to north along the fir forest transect, with evidence of decreasing specific diversity as measured by the Shannon index of diversity. Strong differences in species assemblages were also observed between the southern maple and fir forest sites. The Silphidae and Histeridae were more abundant in the maple forest, whereas the Hydrophilidae and Ptilidae were more abundant in the fir forest.

Hourly and seasonable variation in catch of winter moths and bruce spanworm in pheromone-baited traps

Science.gov (United States)

Joseph Elkinton; Natalie Leva; George Boettner; Roy Hunkins; Marinko. Sremac

2011-01-01

Elkinton et al. recently completed a survey of northeastern North America for the newly invasive winter moth, Operophtera brumata L. The survey used traps baited with the winter moth pheromone, which, as far as it is known, consists of a single compound that is also used by Bruce spanworm, the North American congener of winter moth, O....

Orchid bee baits attracting bees of the genus Megalopta (Hymenoptera, Halictidae in Bauru region, São Paulo, Brazil: abundance, seasonality, and the importance of odors for dim-light bees

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Fátima R. N. Knoll

2012-12-01

Full Text Available Nocturnal bees in the genus Megalopta Smith, 1853 are generally collected using artificial light sources. However, between 1993 and 2000, a total of 946 females (no males were captured were captured using aromatic baits commonly used for orchid bees (Euglossini in five localities in Bauru region, São Paulo, Brazil. Aromatic compounds used in bait traps were: benzyl acetate, eucalyptol, eugenol, skatole, methyl salicylate, and vanillin. The Megalopta species collected were: M. guimaraesi (71.2% of total number of specimens, M. amoena (28.1%, and M. aegis (0.6%. Using the data from these traps, we showed that there was a positive and significant correlation between the abundance of individuals and meteorological factors, rainfall and temperature. Bees were more commonly collected in the spring (September to December and summer (December to March than in the autumn and winter, the latter characterized for being a drier and colder period. Variations in the abundance were also detected among localities and years. The most attractive compounds were eugenol (54%, methyl salicylate (22%, and eucalyptol (16%. The ability to detect smells may have an important role in searching for flowers during dim-light conditions. We suggest the use of aromatic compounds in future studies on the biology of Megalopta in the Neotropical region.

Odor-baited trap trees: a novel management tool for plum curculio (Coleoptera: Curculionidae).

Science.gov (United States)

Leskey, Tracy C; Piñero, Jaime C; Prokopy, Ronald J

2008-08-01

The plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae), one of the most important pests of apple (Malus spp.) in eastern and central North America, historically has been managed in New England apple orchards by three full block insecticide applications. Efforts to reduce insecticide inputs against plum curculio include perimeter row sprays, particularly after petal fall, to control immigrating adults. The odor-baited trap tree approach represents a new reduced input strategy for managing plum curculio based on the application of insecticides to a few perimeter-row trap trees rather than the entire perimeter row or full orchard block. Here, we compared the efficacy of a trap tree approach with perimeter row treatments to manage populations after petal fall in commercial apple orchards in 2005 and 2006. Injury was significantly greater in trap trees compared with unbaited perimeter row treated trees in both years of the study. In 2005, heavy rains prevented growers from applying insecticide applications at regular intervals resulting in high injury in nearly all blocks regardless of type of management strategy. In 2006, both the trap-tree and perimeter-row treatments prevented penetration by immigrating populations and resulted in economically acceptable levels of injury. The trap tree management strategy resulted in a reduction of approximately 70% total trees being treated with insecticide compared with perimeter row sprays and 93% compared with standard full block sprays.

Attractiveness of MM-X traps baited with human or synthetic odor to mosquitoes (Diptera: Culicidae) in The Gambia

NARCIS (Netherlands)

Qiu, Y.T.; Smallegange, R.C.; Braak, ter C.J.F.; Spitzen, J.; Loon, van J.J.A.; Jawara, M.; Milligan, P.; Galimard, A.M.S.; Beek, van T.A.; Knols, B.G.J.; Takken, W.

2007-01-01

Chemical cues play an important role in the host-seeking behavior of blood-feeding mosquitoes (Diptera: Culicidae). A field study was carried out in The Gambia to investigate the effects of human odor or synthetic odor blends on the attraction of mosquitoes. MM-X traps baited with 16 odor blends to

Enhanced selective photocatalytic CO{sub 2} reduction into CO over Ag/CdS nanocomposites under visible light

Energy Technology Data Exchange (ETDEWEB)

Zhu, Zezhou; Qin, Jiani; Jiang, Min; Ding, Zhengxin; Hou, Yidong, E-mail: ydhou@fzu.edu.cn

2017-01-01

Highlights: • Ag/CdS nanocomposites were prepared by a facile photodeposition method. • Ag/CdS was more effective as a photocatalyst for CO{sub 2} reduction than CdS. • Ag as cocatalyst served as electron trap as well as active site for CO{sub 2} reduction reaction. - Abstract: Photocatalytic reduction of carbon dioxide can convert chemically inert carbon dioxide into useful chemical fuel in a mild manner. Herein, Ag-CdS nanocomposites were prepared by photodeposition method and examined for photocatalytic CO{sub 2} reduction under visible light. Meanwhile, the nanocomposites were characterized by XRD, SEM, TEM, XPS, DRS and PL in detail. The results show that, the deposition of Ag improves the photocatalytic performance of CdS, especially in the selectivity of CO{sub 2}-to-CO. The highest photocatalytic activity is achieved over 1.0 wt.% Ag/CdS, with an increase by 3 times in comparison to CdS. In this reaction system, Ag can serve as electron trap as well as active site for CO{sub 2} reduction, which is probably responsible for the enhanced activity and selectivity of CO{sub 2} to CO over Ag/CdS. The possible mechanism of CO{sub 2} photoreduction over Ag/CdS was proposed in view of the abovementioned analysis.

Wettability impact on supercritical CO2 capillary trapping: Pore-scale visualization and quantification

Science.gov (United States)

Hu, Ran; Wan, Jiamin; Kim, Yongman; Tokunaga, Tetsu K.

2017-08-01

How the wettability of pore surfaces affects supercritical (sc) CO2 capillary trapping in geologic carbon sequestration (GCS) is not well understood, and available evidence appears inconsistent. Using a high-pressure micromodel-microscopy system with image analysis, we studied the impact of wettability on scCO2 capillary trapping during short-term brine flooding (80 s, 8-667 pore volumes). Experiments on brine displacing scCO2 were conducted at 8.5 MPa and 45°C in water-wet (static contact angle θ = 20° ± 8°) and intermediate-wet (θ = 94° ± 13°) homogeneous micromodels under four different flow rates (capillary number Ca ranging from 9 × 10-6 to 8 × 10-4) with a total of eight conditions (four replicates for each). Brine invasion processes were recorded and statistical analysis was performed for over 2000 images of scCO2 saturations, and scCO2 cluster characteristics. The trapped scCO2 saturation under intermediate-wet conditions is 15% higher than under water-wet conditions under the slowest flow rate (Ca ˜ 9 × 10-6). Based on the visualization and scCO2 cluster analysis, we show that the scCO2 trapping process in our micromodels is governed by bypass trapping that is enhanced by the larger contact angle. Smaller contact angles enhance cooperative pore filling and widen brine fingers (or channels), leading to smaller volumes of scCO2 being bypassed. Increased flow rates suppress this wettability effect.

Vertically averaged approaches for CO 2 migration with solubility trapping

KAUST Repository

Gasda, S. E.

2011-05-20

The long-term storage security of injected carbon dioxide (CO2) is an essential component of geological carbon sequestration operations. In the postinjection phase, the mobile CO2 plume migrates in large part because of buoyancy forces, following the natural topography of the geological formation. The primary trapping mechanisms are capillary and solubility trapping, which evolve over hundreds to thousands of years and can immobilize a significant portion of the mobile CO2 plume. However, both the migration and trapping processes are inherently complex, spanning multiple spatial and temporal scales. Using an appropriate model that can capture both large- and small-scale effects is essential for understanding the role of these processes on the long-term storage security of CO2 sequestration operations. Traditional numerical models quickly become prohibitively expensive for the type of large-scale, long-term modeling that is necessary for characterizing the migration and immobilization of CO2 during the postinjection period. We present an alternative modeling option that combines vertically integrated governing equations with an upscaled representation of the dissolution-convection process. With this approach, we demonstrate the effect of different modeling choices for typical large-scale geological systems and show that practical calculations can be performed at the temporal and spatial scales of interest. Copyright 2011 by the American Geophysical Union.

Mosquito Traps: An Innovative, Environmentally Friendly Technique to Control Mosquitoes

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Brigitte Poulin

2017-03-01

Full Text Available We tested the use of mosquito traps as an alternative to spraying insecticide in Camargue (France following the significant impacts observed on the non-target fauna through Bti persistence and trophic perturbations. In a village of 600 inhabitants, 16 Techno Bam traps emitting CO2 and using octenol lures were set from April to November 2016. Trap performance was estimated at 70% overall based on mosquitoes landing on human bait in areas with and without traps. The reduction of Ochlerotatus caspius and Oc. detritus, the two species targeted by Bti spraying, was, respectively, 74% and 98%. Traps were less efficient against Anopheles hyrcanus (46%, which was more attracted by lactic acid than octenol lures based on previous tests. Nearly 300,000 mosquitoes from nine species were captured, with large variations among traps, emphasizing that trap performance is also influenced by surrounding factors. Environmental impact, based on the proportion of non-target insects captured, was mostly limited to small chironomids attracted by street lights. The breeding success of a house martin colony was not significantly affected by trap use, in contrast to Bti spraying. Our experiment confirms that the deployment of mosquito traps can offer a cost-effective alternative to Bti spraying for protecting local populations from mosquito nuisance in sensitive natural areas.

Monitoring Pseudococcus calceolariae (Hemiptera: Pseudococcidae) in Fruit Crops Using Pheromone-Baited Traps.

Science.gov (United States)

Flores, M Fernanda; Romero, Alda; Oyarzun, M Soledad; Bergmann, Jan; Zaviezo, Tania

2015-10-01

The citrophilus mealybug, Pseudococcus calceolariae (Maskell), is an important pest of fruit crops in many regions of the world. Recently, its sex pheromone has been identified and synthesized. We carried out field experiments with the goal of developing monitoring protocols for P. calceolariae using pheromone-baited traps. Traps checked hourly for 24 hours showed a distinct diel pattern of male flight, between 18:00 and 21:00 h. The presence of unnatural stereoisomers did not affect trap captures, with isomeric mixtures capturing similar amounts of males as the biological active isomer. Dose of isomeric mixture pheromone (0-100 µg) had a nonlinear effect on male captures, with 10, 30, and 50 µg capturing similar amounts. The effective range of pheromone traps was determined by placing traps at different distances (15, 40, and 80 m) from an infested blueberry field, loaded with 0, 1 and 25 µg of the pheromone. For all distances, 25 µg dose captured more males, and was highly attractive up to 40 m. There was a significant effect of lure age on male captures (0-150 d), with similar amount of males captured up to 90-day-old lure, and lower captures in the 150-day-old lure compared with fresh ones. We found significant positive correlations between P. calceolariae males caught in pheromone traps with female abundance and fruit infestation at harvest. Our results show the usefulness of P. calceolariae pheromones for monitoring at field level and provide information for the design of monitoring protocols. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Rules of attraction: The role of bait in small mammal sampling at ...

African Journals Online (AJOL)

Baits or lures are commonly used for surveying small mammal communities, not only because they attract large numbers of these animals, but also because they provide sustenance for trapped individuals. In this study we used Sherman live traps with five bait treatments to sample small mammal populations at three ...

Fish assemblages associated with natural and anthropogenically-modified habitats in a marine embayment: comparison of baited videos and opera-house traps.

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Corey B Wakefield

Full Text Available Marine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment and modified (rockwall and dredge channel habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment.

Comparison of ethanolamine and potassium hydroxide as quantitative trapping agents for radiolabeled CO2 in metabolism studies

International Nuclear Information System (INIS)

Medinsky, M.A.

1984-01-01

The efficiency of ethanolamine and potassium hydroxide as trapping agents for CO 2 was tested using a flow of 500 ml/min through CO 2 absorption towers containing trapping solutions. Radiolabeled CO 2 was produced by acidification of suspensions containing Ba 14 CO 3 . With 200 ml of ethanolamine, trapping efficiency of 14 CO 2 decreased when only 5% or less of the amount of ethanolamine available had reacted (22 mmoles of CO 2 trapped). In contrast, use of 200 ml of 1 M or 5 M KOH was effective in retaining 88 mmoles of CO 2 . This is equivalent to the amount of CO 2 produced by a rat over an 8-hour period

Comparison of ethanolamine and potassium hydroxide as quantitative trapping agents for radiolabeled CO2 in metabolism studies

International Nuclear Information System (INIS)

Medinsky, M.A.

1986-01-01

The efficiency of ethanolamine and potassium hydroxide (KOH) as trapping agents for CO 2 was determined using a flow of 500 mL/min through CO 2 absorption towers containing trapping solution. Radiolabeled 14 CO 2 was produced by acidification of suspensions containing Ba 14 CO 3 . Both 100% ethanolamine and 5M ethanolamine in 2-methoxyethanol were evaluated. With 200 mL of either solution, trapping efficiency of 14 CO 2 decreased when only 5% or less of the amount of ethanolamine available had reacted (22 mmoles of CO 2 ) trapped). In contrast, use of 200 mL of 1M or 5M KOH was effective in retaining 88 mmoles of CO 2 . This is equivalent to the amount of CO 2 produced by a rat over an 8-hr period. In summary, with flow rates commonly used in in vivo metabolism studies, the trapping efficiency of ethanolamine was far less than the theoretical efficiency. In these types of studies KOH would be a more suitable trapping agent or, if used, ethanolamine solutions must be changed frequently

TYPE OF LIGHT IN SAND FLY CAPTURES (DIPTERA:PSYCHODIDAE

Directory of Open Access Journals (Sweden)

VERÔNICA DE LOURDES SIERPE JERALDO

2012-09-01

Full Text Available The number of cases of visceral leishmaniasis in Brazil has been gradually increasing, and one of the strategies to reduce the transmission of this disease is based on the control of the adult forms of its vectors. It is therefore of great epidemiological importance to develop more refined methods for monitoring and controlling its vectors, which are the phlebotomine sand flies, or biting midges. The present study compares the attraction exercised by UV light in comparison with conventional incandescent, or white, light in catching phlebotomine sand flies. Traps baited with UV light caught higher numbers of these flies than traps baited with white light, indicating the potential use of UV light, especially in locations of low demographic density of the flies.

Medfly (Ceratitis capitata Wiedemann) female attractant studies and development of trapping systems for sterility assessment

International Nuclear Information System (INIS)

Vasquez, L.A.; Sponagel, K.

1999-01-01

In four years of research, we evaluated different traps (McPhail, Tephri, Closed-bottom dry trap, Open-bottom dry trap, and Frutect), lures (FA-2 and FA-3 synthetic lures composed of ammonium acetate + putrescine, and ammonium acetate + putrescine + trimethylamine, respectively), and insect retention methods (water, sticky inserts, insecticides) to develop a selective trapping system for female Mediterranean fruit fly (Ceratitis capitata, Wiedemann) sterility assessment. The trapping systems were compared with protein-baited McPhail traps, which are the standard method for C. capitata female capture, during eight to fifteen week trials in coffee and orthanique orange plantations at two different localities in Honduras. Trimedlure-baited Jackson traps were also used as the standard indicator of the C. capitata populations. The Closed-bottom trap baited with the two-component synthetic lure captured eight to twelve times fewer C. capitata than the Jackson trap. The McPhail trap and the modified Open-bottom trap, both baited with the two-component synthetic lure, captured 1.6 to 3.5 times more C. capitata females than the protein-baited McPhail trap. The addition of trimethylamine to the two-component synthetic lure resulted in 9.8 to 15.8 times increases in C. capitata female capture over the protein-baited McPhail trap. The presence of water in McPhail or Tephri traps did not affect the capture of C. capitata females. Throughout the study, all female-targeted trapping systems captured the same proportion of females. (author)

Pore scale study of multiphase multicomponent reactive transport during CO2 dissolution trapping

Science.gov (United States)

Chen, Li; Wang, Mengyi; Kang, Qinjun; Tao, Wenquan

2018-06-01

Solubility trapping is crucial for permanent CO2 sequestration in deep saline aquifers. For the first time, a pore-scale numerical method is developed to investigate coupled scCO2-water two-phase flow, multicomponent (CO2(aq), H+, HCO3-, CO32- and OH-) mass transport, heterogeneous interfacial dissolution reaction, and homogeneous dissociation reactions. Pore-scale details of evolutions of multiphase distributions and concentration fields are presented and discussed. Time evolutions of several variables including averaged CO2(aq) concentration, scCO2 saturation, and pH value are analyzed. Specific interfacial length, an important variable which cannot be determined but is required by continuum models, is investigated in detail. Mass transport coefficient or efficient dissolution rate is also evaluated. The pore-scale results show strong non-equilibrium characteristics during solubility trapping due to non-uniform distributions of multiphase as well as slow mass transport process. Complicated coupling mechanisms between multiphase flow, mass transport and chemical reactions are also revealed. Finally, effects of wettability are also studied. The pore-scale studies provide deep understanding of non-linear non-equilibrium multiple physicochemical processes during CO2 solubility trapping processes, and also allow to quantitatively predict some important empirical relationships, such as saturation-interfacial surface area, for continuum models.

Successful removal of German yellowjackets (Hymenoptera: Vespidae) by toxic baiting.

Science.gov (United States)

Sackmann, P; Rabinovich, M; Corley, J C

2001-08-01

Vespula germanica (F.) is a social vespid that has invaded many parts of the world, including Argentina. This wasp usually becomes a pest, affecting several economic activities. It also may impact the host community through predation or competition. The purpose of our study was to field test toxic baiting for reduction of wasp abundance. Wasps were poisoned with 0.1% fipronil mixed with raw minced beef in two beech forest sites on 20 February 2000 in northwestern Patagonia. All nests (46) within the two 6-ha sites with poisoned bait stations were killed, whereas Malaise traps in those sites captured 81.1% fewer wasps at the end of the season than traps in the two control sites. The average reduction of forager wasps on nontoxic baits was 87%. Fipronil was very effective in controlling wasp numbers, although there are limitations to the method, especially concerning conservation purposes. Toxic baiting can be useful in controlling wasp numbers in honey bee hive yards, farms, and parks.

Response of Anastrepha suspensa to liquid protein baits and synthetic lure formulations

International Nuclear Information System (INIS)

Epsky, Nancy D.; Kendra, Paul E.; Heath, Robert R.

2006-01-01

Traps baited with AAPt captured more A. suspensa than traps baited with ABPt even when the ammonia release rates were similar. Reducing dosage of ammonia by 50% of the commercially available AA lure slightly increased female capture, but reducing dosage to 25% tended to decrease female capture. The 5% CPH/3% borax bait captured the same number of flies as TYB, and was more effective than 10% CPH/3% borax. Further decreasing the amount of borax added to CPH may improve its effectiveness. As has been observed in field tests, fresh TYB captures more A. suspensa than fresh Nulure/borax but this difference decreases as the bait solutions age. EAG analysis indicates that volatiles from fresh Nulure/ borax elicit a higher antennal response than TYB, but this difference decreases as the TYB solution ages. Chemical analysis will be needed to determine the nature of reduced capture by fresh Nulure/borax and to identify additional attractive chemicals emitted by these protein baits. (author)

Response of Anastrepha suspensa to liquid protein baits and synthetic lure formulations

Energy Technology Data Exchange (ETDEWEB)

Epsky, Nancy D.; Kendra, Paul E.; Heath, Robert R., E-mail: Nancy.Epsky@ars.usda.go, E-mail: Paul.Kendra@ars.usda.go, E-mail: Bob.Heath@ars.usda.go [U.S. Department of Agriculture (USDA/ARS/SHRS), Miami, FL (United States). Agricultural Research Service. Subtropical Horticulture Research Station

2006-07-01

Traps baited with AAPt captured more A. suspensa than traps baited with ABPt even when the ammonia release rates were similar. Reducing dosage of ammonia by 50% of the commercially available AA lure slightly increased female capture, but reducing dosage to 25% tended to decrease female capture. The 5% CPH/3% borax bait captured the same number of flies as TYB, and was more effective than 10% CPH/3% borax. Further decreasing the amount of borax added to CPH may improve its effectiveness. As has been observed in field tests, fresh TYB captures more A. suspensa than fresh Nulure/borax but this difference decreases as the bait solutions age. EAG analysis indicates that volatiles from fresh Nulure/ borax elicit a higher antennal response than TYB, but this difference decreases as the TYB solution ages. Chemical analysis will be needed to determine the nature of reduced capture by fresh Nulure/borax and to identify additional attractive chemicals emitted by these protein baits. (author)

Residual and Solubility trapping during Geological CO2 storage : Numerical and Experimental studies

OpenAIRE

Rasmusson, Maria

2018-01-01

Geological storage of carbon dioxide (CO2) in deep saline aquifers mitigates atmospheric release of greenhouse gases. To estimate storage capacity and evaluate storage safety, knowledge of the trapping mechanisms that retain CO2 within geological formations, and the factors affecting these is fundamental. The objective of this thesis is to study residual and solubility trapping mechanisms (the latter enhanced by density-driven convective mixing), specifically in regard to their dependency on ...

Evaluation of double-decker traps for emerald ash borer (Coleoptera: Buprestidae).

Science.gov (United States)

Poland, Therese M; McCullough, Deborah G; Anulewicz, Andrea C

2011-04-01

Improved detection tools are needed for the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive forest insect from Asia that has killed millions of ash (Fraxinus spp.) trees in North America since its discovery in Michigan in 2002. We evaluated attraction of adult A. planipennis to artificial traps incorporating visual (e.g., height, color, silhouette) and olfactory cues (e.g., host volatiles) at field sites in Michigan. We developed a double-decker trap consisting of a 3-m-tall polyvinyl pipe with two purple prisms attached near the top. In 2006, we compared A. planipennis attraction to double-decker traps baited with various combinations of manuka oil (containing sesquiterpenes present in ash bark), a blend of four ash leaf volatiles (leaf blend), and a rough texture to simulate bark. Significantly more A. planipennis were captured per trap when traps without the rough texture were baited with the leaf blend and manuka oil lures than on traps with texture and manuka oil but no leaf blend. In 2007, we also tested single prism traps set 1.5 m above ground and tower traps, similar to double-decker traps but 6 m tall. Double-decker traps baited with the leaf blend and manuka oil, with or without the addition of ash leaf and bark extracts, captured significantly more A. planipennis than similarly baited single prism traps, tower traps, or unbaited double-decker traps. A baited double-decker trap captured A. planipennis at a field site that was not previously known to be infested, representing the first detection event using artificial traps and lures. In 2008, we compared purple or green double-decker traps, single prisms suspended 3-5 m above ground in the ash canopy (canopy traps), and large flat purple traps (billboard traps). Significantly more A. planipennis were captured in purple versus green traps, baited traps versus unbaited traps, and double-decker versus canopy traps, whereas billboard traps were intermediate. At sites

Geometric light trapping with a V-trap for efficient organic solar cells

KAUST Repository

Kim, Soo Jin

2013-03-14

The efficiency of today’s most efficient organic solar cells is primarily limited by the ability of the active layer to absorb all the sunlight. While internal quantum efficiencies exceeding 90% are common, the external quantum efficiency rarely exceeds 70%. Light trapping techniques that increase the ability of a given active layer to absorb light are common in inorganic solar cells but have only been applied to organic solar cells with limited success. Here, we analyze the light trapping mechanism for a cell with a V-shape substrate configuration and demonstrate significantly improved photon absorption in an 5.3%-efficient PCDTBT:PC70BM bulk heterojunction polymer solar cell. The measured short circuit current density improves by 29%, in agreement with model predictions, and the power conversion efficiency increases to 7.2%, a 35% improvement over the performance in the absence of a light trap.

Improved visible-light photocatalytic activity of TiO2 co-doped with copper and iodine

Science.gov (United States)

Dorraj, Masoumeh; Goh, Boon Tong; Sairi, Nor Asrina; Woi, Pei Meng; Basirun, Wan Jefrey

2018-05-01

Cu-I-co-doped TiO2 photocatalysts active to visible light absorption were prepared by hydrothermal method and calcined at various temperatures (350 °C, 450 °C, and 550 °C). The co-doped powders at 350 °C displayed the highest experimental Brunauer-Emmett-Teller surface area and lowest photoluminescence intensity, which demonstrated that a decrease in electron-hole recombination process. The synthesis of co-doped TiO2 was performed at this optimized temperature. In the co-doped sample, the Cu2+ doped TiO2 lattice created a major "red-shift" in the absorption edge due to the presence of the 3d Cu states, whereas the amount of red-shift from the I5+ doping in the TiO2 lattice was minor. Interestingly, the presence of Cu2+ species also boosted the reduction of I5+ ions to the lower multi-valance state I- in the TiO2 lattice by trapping the photogenerated electrons, which resulted in effective separation of the photogenerated charges. The Cu-I-co-doped TiO2 was able to degrade methyl orange dye under visible-light irradiation with improved photocatalytic activity compared with the single metal-doped TiO2 and pure TiO2 because of the strong visible light absorption and effective separation of photogenerated charges caused by the synergistic effects of Cu and I co-dopants.

Developing a passive trap for diffusive atmospheric {sup 14}CO{sub 2} sampling

Energy Technology Data Exchange (ETDEWEB)

Walker, Jennifer C.; Xu, Xiaomei [Department of Earth System Science, University of California, Irvine, Irvine, CA (United States); Fahrni, Simon M. [Department of Earth System Science, University of California, Irvine, Irvine, CA (United States); Institute of Particle Physics, ETH, Zurich (Switzerland); Lupascu, Massimo [Department of Earth System Science, University of California, Irvine, Irvine, CA (United States); Department of Geography, National University of Singapore (Singapore); Czimczik, Claudia I. [Department of Earth System Science, University of California, Irvine, Irvine, CA (United States)

2015-10-15

{sup 14}C-CO{sub 2} measurement is an unique tool to quantify source-based emissions of CO{sub 2} for both the urban and natural environments. Acquiring a sample that temporally integrates the atmospheric {sup 14}C-CO{sub 2} signature that allows for precise {sup 14}C analysis is often necessary, but can require complex sampling devices, which can be difficult to deploy and maintain, especially for multiple locations. Here we describe our progress in developing a diffusive atmospheric CO{sub 2} molecular sieve trap, which requires no power to operate. We present results from various cleaning procedures, and rigorously tested for blank and memory effects. Traps were tested in the environment along-side conventional sampling flasks for accuracy. Results show that blank and memory effects can be minimized with thorough cleaning and by avoiding overheating, and that diffusively collected air samples agree well with traditionally canister-sampled air.

Evidence that grey seals (Halichoerus grypus use above-water vision to locate baited buoys

Directory of Open Access Journals (Sweden)

Arne Fjälling

2007-01-01

Full Text Available Fishing gear in the Baltic is often raided by grey seals (Halichoerus grypus. The seals remove the fish and damage the nets, or entangle themselves and drown. In order to develop ways of mitigating the seals-fisheries conflict, it is important to know exactly how the seals locate the fishing gear. A field experiment was conducted in order to clarify whether seals use their vision above water to do this. Bait (herring; Clupea harengus was attached to the anchor lines of buoys of the type that is commonly used to mark the position of fishing gear. In all, 643 buoys were set. Some of the buoys (210 were also fitted with camera traps. Weather data were collected from official weather stations nearby. Bait loss (mean 18% was significantly correlated with buoy size (P = 0.002 and wind speed (P = 0.04. There was a significant association between bait loss and seal observations near the buoys (P = 0.05. Five photos of grey seals were obtained from the camera traps. No fish-eating birds, such as cormorants or mergansers, were ever observed near the buoys or caught on camera. It was concluded that a main cause of missing bait was scavenging by grey seals, and that they did use above-water vision to locate the buoys. It was also concluded that wind strength (i.e. wave action contributed tothe bait loss. The camera trap buoys had a somewhat lower bait loss than the other buoys (P = 0.054, which was attributed to a scaring effect. Neither the number of seal observations nor the bait loss differed significantly between the 2 study areas in the experiment (P = 0.43 and P = 0.83, respectively. Bait loss was not affected by the buoy colour (red, white, or grey; P = 0.87. We suggest that the findings of this experiment could be put into practice in a seal-disturbed area by deploying a number of decoy buoys, or by hiding live buoys below the surface of the water. This would increase the cost of foraging for the seals, and hence discourage them from exploiting

Trapping of CH4, CO, and CO2 in Amorphous Water Ice

Science.gov (United States)

Mastrapa, R. M. E.; Brown, R. H.; Anicich, V. G.; Cohen, B. A.; Dai, W.; Lunine, J. I.

1999-09-01

In this study, CO, CH4, and CO2 were trapped in H2O at temperatures as low as 20 K and pressures between 10-5 and 10-8 Torr. IR spectra were taken of each sample before sublimation to confirm the presence of volatiles. The samples were then heated at rates from 0.25 K/min to 1 K/min and the escape ranges were measured with a mass spectrometer. The volatiles escaped from the ice mixtures in temperature ranges similar to those found in previous work (1, 2, 3), namely 48-52 K, 145-160 K, 170-185 K. H2O is released from 150 K to 185 K. However, the temperature range of escape is strongly dependent on deposition temperature and heating rate. If the deposition temperature is below the point where the solid volatile rapidly sublimates in the ambient environment of our experiment, then the first range of volatile escape is centered around it's sublimation point, and there is little of the volatile remaining from 170-185 K. The location of the third escape range shifts to lower temperatures with slower sublimation rate. It was determined that 0.5 K/min is the ideal sample heating rate to determine these escape ranges. In our data, the infrared spectrum of CO trapped in water ice shows a splitting of the 2145 cm-1 solid CO line into two bands at 2343 cm-1 and 2135 cm-1. These shifts are similar to those seen by Sandford, et al. (4). (1) Bar-Nun, A., G. Herman, D. Laufer, and M. L. Rappaport, (1985), Icarus, 63, 317-332. (2) Bar-Nun, A., J. Dror, E. Kochavi, and D. Laufer, (1987), Physical Review B, 35, no. 5, 2427-2435. (3) Hudson, R. L., and B. Donn, (1991), Icarus, 94, 326-332. (4) Sandford, S. A., L. J. Allamandola, A. G. G. M. Tielens, and G. J. Valero, (1988), Astrophysical Journal, 329, 498-510.

Wettability effect on capillary trapping of supercritical CO2 at pore-scale: micromodel experiment and numerical modeling

Science.gov (United States)

Hu, R.; Wan, J.

2015-12-01

Wettability of reservoir minerals along pore surfaces plays a controlling role in capillary trapping of supercritical (sc) CO2 in geologic carbon sequestration. The mechanisms controlling scCO2 residual trapping are still not fully understood. We studied the effect of pore surface wettability on CO2 residual saturation at the pore-scale using engineered high pressure and high temperature micromodel (transparent pore networks) experiments and numerical modeling. Through chemical treatment of the micromodel pore surfaces, water-wet, intermediate-wet, and CO2-wet micromodels can be obtained. Both drainage and imbibition experiments were conducted at 8.5 MPa and 45 °C with controlled flow rate. Dynamic images of fluid-fluid displacement processes were recorded using a microscope with a CCD camera. Residual saturations were determined by analysis of late stage imbibition images of flow path structures. We performed direct numerical simulations of the full Navier-Stokes equations using a volume-of-fluid based finite-volume framework for the primary drainage and the followed imbibition for the micromodel experiments with different contact angles. The numerical simulations agreed well with our experimental observations. We found that more scCO2 can be trapped within the CO2-wet micromodel whereas lower residual scCO2 saturation occurred within the water-wet micromodels in both our experiments and the numerical simulations. These results provide direct and consistent evidence of the effect of wettability, and have important implications for scCO2 trapping in geologic carbon sequestration.

Evaluation of the efficiency of various medfly female trapping combinations in Costa Rica in support of the sterile insect technique

Energy Technology Data Exchange (ETDEWEB)

Camacho, H [Laboratorio de Investigacion en Mosca del Mediterraneo, Escuela de Biologia, Universidad de Costa Rica, San Jose (Costa Rica)

1999-07-01

This report contains information from a four-year research programme co-ordinated by the International Atomic Energy Agency. The objective of the programme was to develop a trapping system for females of the Mediterranean fruit fly (medfly), Ceratitis capitata (Diptera: Tephritidae), for practical use in Sterile Insect Technique (SIT) programs and to design and evaluate a trap to obtain eggs from wild female medflies in order to estimate sterility induction in the field population. The study was carried out at two different Agricultural Research Stations of the University of Costa Rica, the Fabio Baudrit Agricultural Research Station (FBS) and Laguna de Fraijanes Agricultural Research Station (LFS), and in a privately-owned coffee and orange plantation in Grecia canton (Coope-Victoria Farm). Female medfly attractants tested were three food based `female` attractants (FA-3), namely ammonium acetate (AA), 1,4 diaminobutane (putrescine) and trimethylamine, all formulated to last at least one month. These attractants were evaluated either in combinations of two (AA + putrescine, termed FA-2) or all three (termed FA-3). The attractants were tested in various traps including the plastic International Pheromone`s McPhail traps (IPMT) and Tephri traps, a Spanish trap similar to the IPMT. Traps were used either as a dry trap (provided with DDVP) or a wet trap (provided with water and 0.01% surfactant). Jackson traps with Trimedlure (JT,TML), a routinely used male medfly trapping system, was also used. Trapping experiments conducted in the citrus plantation of the FBS resulted in the following fly/trap/day indices (F/T/D): 7.18 with JT,TML; 4.62 with open bottom dry traps (OBDT) baited with FA-3; 4.18 with OBDT (PVC) baited with FA-3; 7.73 with IPMT baited with FA-3, wet; 8.245 with IPMT baited with FA-3, dry; 5.27 with IPMT baited with NuLure; 4.79 with Tephri baited with FA-3, wet; and 5.42 with Tephri, FA-3, dry. The F/T/D indices at the Coope-Victoria Farm, in coffee

Improved light trapping in polymer solar cells by light diffusion ink

International Nuclear Information System (INIS)

Chao, Yu-Chiang; Lin, Yun-Hsuan; Lin, Ching-Yi; Li, Husan-De; Zhan, Fu-Min; Huang, Yu-Zhang

2014-01-01

Light trapping is an important issue for solar cells to increase optical path length and optical absorption. In this work, a light trapping structure was realized for polymer solar cells by utilizing light diffusion ink which is conventionally used in display backlighting. The light scattering particles in the ink cause the deflection of light, and the number of these particles coated on a glass substrate determines the light transmission and scattering characteristics. It was observed that the short-circuit current density did not decrease with decreasing transmittance, but it increased to a highest value at an optimized transmittance. This behaviour is attributed to the trapping of scattered light in the photoactive layer. (paper)

Development of a local baiting system for the control of the Africa invader fly, (Bactrocera invadens) Drew, Tsuruta and White (Diptera: Tephritidae) in mango orchards at Somanya, Eastern Ghana

International Nuclear Information System (INIS)

Yeboah, S.

2012-01-01

, 2012. The selected area was divided into three to constitute a randomised complete block design. The traps were replicated three times. The coloured traps were randomly suspended on selected trees in two rows, 15m from each other within each block and about 2m from the ground. The cotton wads hanging inside the traps were soaked with the baits incorporated with fenitrothion insecticide. Fly catches were collected weekly, recorded and the traps recharged. Counts of fly catches were log-transformed, subjected to analysis of variance and least significance difference determined. Results of the study showed that the percentage of supernatant increased slightly after pasteurisation, with a corresponding decrease in the sediment mixture. However, the quantity of yeast cell sediments used for pasteurisation did not affect the protein content of the bait. Protein content of Guiness, Beer, Pito and Commercial baits were 1.4%, 5.2%, 1.4%, and 8.0% respectively. Beer bait was found to be significantly attractive with peak fly catch of 7.19 flies per trap per week (F/T/W). Guiness and Commercial bait were not significantly different in their fly catches with peak catches of 6.54 F/T/W and 6.61 F/T/W respectively. In season I, green coloured traps recorded the highest fly density of 5.56 flies per trap per day (F/T/D), while yellow coloured traps captured the highest with 17.11 F/T/D in season II. The relative fly density in the study area was estimated to be 4.68 F/T/D in the minor season and 14.64 F/T/D in the major season. An overall sex ratio of female B. Invadens was 77%. Beer bait proves to be more efficient and effective in controlling B. Invadens. Large scale production of protein bait for effective monitoring and control programmes should therefore combine Beer protein autolysate and green or yellow coloured traps in a baiting system. [au

Levitated atoms in a CO2 laser trap: towards BEC with cesium

International Nuclear Information System (INIS)

Herbig, J.; Weber, T.; Naegerl, H.-C.; Grimm, R.

2001-01-01

Full text: Since the standard approach towards Bose-Einstein condensation has failed for cesium, we are exploring a novel concept employing an optical dipole trap formed by intense CO2 lasers. These provide a conservative and large-volume trapping potential. In order to compensate the gravitational force, a magnetic field gradient along the vertical axis is applied. This counterbalances gravitation for the absolute internal ground state of Cs (F=3, mF=3), effectively levitating those atoms. Other spin states are expelled from the trap, opening up a path for rf exploration. Our approach to trap the lowest spin state at low densities minimizes inelastic processes. The free choice of a magnetic bias field allows exploration of Feshbach resonances to tune scattering properties. (author)

The Electronic McPhail Trap

Science.gov (United States)

Potamitis, Ilyas; Rigakis, Iraklis; Fysarakis, Konstantinos

2014-01-01

Certain insects affect cultivations in a detrimental way. A notable case is the olive fruit fly (Bactrocera oleae (Rossi)), that in Europe alone causes billions of euros in crop-loss/per year. Pests can be controlled with aerial and ground bait pesticide sprays, the efficiency of which depends on knowing the time and location of insect infestations as early as possible. The inspection of traps is currently carried out manually. Automatic monitoring traps can enhance efficient monitoring of flying pests by identifying and counting targeted pests as they enter the trap. This work deals with the hardware setup of an insect trap with an embedded optoelectronic sensor that automatically records insects as they fly in the trap. The sensor responsible for detecting the insect is an array of phototransistors receiving light from an infrared LED. The wing-beat recording is based on the interruption of the emitted light due to the partial occlusion from insect's wings as they fly in the trap. We show that the recordings are of high quality paving the way for automatic recognition and transmission of insect detections from the field to a smartphone. This work emphasizes the hardware implementation of the sensor and the detection/counting module giving all necessary implementation details needed to construct it. PMID:25429412

Comparison of catching efficiency of two Indonesian traditional traps, Ayunan and Tamba

Directory of Open Access Journals (Sweden)

Ahmadi

2014-08-01

Full Text Available The catching efficiency of traditional traps: Ayunan and Tamba were tested in Sungai Batang River, South Kalimantan of Indonesia. Trials consisted of 320-trap hauls/type using 1-day submersion time of 24 hr. The baited traps sampling accounted for 82 specimens assigned to 5 species of 5 families. There was a large variability in number of catch between prawns and fish species collected (T=2.318, P<0.05. The prawns catch was represented by only the species Macrobrachium rossenbergii with total of 53 and 1,015 g weight. The prawns weight of Tamba was significantly higher than that of Ayunan (T=3.453, P<0.01.The fish catch composed of Mystus gulio 79%, Osteochilus hasselti 10%, Hypostomus plecostomus 7%, and Macrognathus aculeatus 3%, with total weight ranged from 35 to 560 g. A clear difference was found in catching efficiency. Comparative fishing trials showed that Tamba collected specimens were 1.8 times higher than Ayunan (T=2.223, P<0.05. Catch per unit effort for Tamba ranged from 58.13 to 80.00, and for Ayunan ranged from 5.31 to 7.19. The gear modifications and various treatments (e.g. bait odor, light are necessary to be taken to increase their relative catching efficiency.

Effect of light trapping in an amorphous silicon solar cell

International Nuclear Information System (INIS)

Iftiquar, S.M.; Jung, Juyeon; Park, Hyeongsik; Cho, Jaehyun; Shin, Chonghoon; Park, Jinjoo; Jung, Junhee; Bong, Sungjae; Kim, Sunbo; Yi, Junsin

2015-01-01

Light trapping in amorphous silicon based solar cell has been investigated theoretically. The substrate for these cells can be textured, including pyramidally textured c-Si wafer, to improve capture of incident light. A thin silver layer, deposited on the substrate of an n–i–p cell, ultimately goes at the back of the cell structure and can act a back reflector to improve light trapping. The two physical solar cells we investigated had open circuit voltages (V oc ) of 0.87, 0.90 V, short circuit current densities (J sc ) of 14.2, 15.36 mA/cm 2 respectively. The first cell was investigated for the effect on its performance while having and not having light trapping scheme (LT), when thickness of the active layer (d i ) was changed in the range of 100 nm to 800 nm. In both the approaches, for having or not having LT, the short circuit current density increases with d i while the V oc and fill factor, decreases steadily. However, maximum cell efficiency can be obtained when d i = 400 nm, and hence it was considered optimized thickness of the active layer, that was used for further investigation. With the introduction of light trapping to the second cell, it shows a further enhancement in J sc and red response of the external quantum efficiency to 16.6 mA/cm 2 and by 11.1% respectively. Considering multiple passages of light inside the cell, we obtained an improvement in cell efficiency from 9.7% to 10.6%. - Highlights: • A theoretical analysis of light trapping in p–i–n and n–i–p type solar cells • J sc increases and V oc decreases with the increase in i-layer thickness. • Observed optimized thickness of i-layer as 400 nm • J sc improved from 15.4 mA/cm 2 to 16.6 mA/cm 2 due to the light trapping. • Efficiency (η) improved from 9.7% to 10.6% due to better red response of the EQE

Development of female fruit fly, Ceratitis species, attractant systems for trapping and sterility assessment in South Africa

International Nuclear Information System (INIS)

Eyles, D.K.; Du Plessis, N.; Barnes, B.N.

1999-01-01

Fruit in the Western Cape Province of South Africa is attacked by the Mediterranean fruit fly, Ceratitis capitata, and the Natal fruit fly, C. rosa. Control costs and crop losses amount to an estimated US$ 5 million per year. The ARC-Fruit, Vine and Wine Research Institute in Stellenbosch has been taking part in the FAO/IAEA Co-ordinated Research Programme (CRP) to develop a female attractant systems for C. capitata during the 1996/97 and 1997/98 growing seasons. These seasons represented Year 3 and Year 4, respectively, of the female attractant CRP. The performance of these attractant systems in monitoring C. rosa was also evaluated. The Year 3 trial was carried out in a plum orchard with a low fruit fly population, and the Year 4 trial was carried out in the same plum orchard, as well as in a pear orchard with a high fruit fly population. Four female trapping systems were evaluated in Year 3 and five in Year 4. In Year 3, two systems consisted of a locally-manufactured buckettype 'Sensus' trap containing one of two different female attractants (β-caryophyllene, or β-caryophyllene + protein hydrolysate), one was a McPhail trap (IPMT) baited with borax + protein hydrolysate, and the fourth was an open bottom dry trap (OBDT) baited with the three component ammonium acetate, putrescine and trimethylamine system (FA-3). Sensus traps and Jackson traps baited with the male fruit fly attractant Trimedlure (TML) were also included. In Year 4, there was one wet and one dry IPMT system (both baited with FA-3), one IPMT system (borax + protein hydrolysate), and one wet and one dry Tephri trap system (both with FA-3). Jackson traps baited with TML were also included. Results from Year 3 showed that of the systems tested, the best female C. capitata attractant systems under low population conditions were the IPMT system baited with borax + protein hydrolysate, and the OBDT system baited with FA-3. β-caryophyllene in a Sensus trap did not adequately attract female C

Photonic crystals for light trapping in solar cells

Energy Technology Data Exchange (ETDEWEB)

Gjessing, Jo

2012-07-25

Solar energy is an abundant and non-polluting source of energy. Nevertheless, the installation of solar cells for energy production is still dependent on subsidies in most parts of the world. One way of reducing the costs of solar cells is to decrease their thickness. This will reduce material consumption and, at the same time, unlock the possibility of using cheaper lower quality solar cell material. However, a thinner solar cell will have a higher optical loss due to insufficient absorption of long wavelength light. Therefore, light-trapping must be improved in order to make thin solar cells economically viable. In this thesis I investigate the potential for light-trapping in thin silicon solar cells by the use of various photonic crystal back-side structures. The first structure I study consists of a periodic array of cylinders in a configuration with a layer of silicon oxide separating the periodic structure from the rear metal reflector. This configuration reduces unwanted parasitic absorption in the reflector and the thickness of the oxide layer provides a new degree of freedom for improving light trapping from the structure. I use a large-period and a small-period approximation to analyze the cylinder structure and to identify criteria that contributes to successful light-trapping. I explore the light-trapping potential of various periodic structures including dimples, inverted pyramids, and cones. The structures are compared in an optical model using a 20 m thick Si slab. I find that the light trapping potential differs between the structures, that the unit cell dimensions for the given structure is more important for light trapping than the type of structure, and that the optimum lattice period does not differ significantly between the different structures. The light-trapping effect of the structures is investigated as a function on incidence angle. The structures provide good light trapping also under angles of incidence up to 60 degrees. The behavior

Photonic crystals for light trapping in solar cells

International Nuclear Information System (INIS)

Gjessing, Jo

2012-01-01

Solar energy is an abundant and non-polluting source of energy. Nevertheless, the installation of solar cells for energy production is still dependent on subsidies in most parts of the world. One way of reducing the costs of solar cells is to decrease their thickness. This will reduce material consumption and, at the same time, unlock the possibility of using cheaper lower quality solar cell material. However, a thinner solar cell will have a higher optical loss due to insufficient absorption of long wavelength light. Therefore, light-trapping must be improved in order to make thin solar cells economically viable. In this thesis I investigate the potential for light-trapping in thin silicon solar cells by the use of various photonic crystal back-side structures. The first structure I study consists of a periodic array of cylinders in a configuration with a layer of silicon oxide separating the periodic structure from the rear metal reflector. This configuration reduces unwanted parasitic absorption in the reflector and the thickness of the oxide layer provides a new degree of freedom for improving light trapping from the structure. I use a large-period and a small-period approximation to analyze the cylinder structure and to identify criteria that contributes to successful light-trapping. I explore the light-trapping potential of various periodic structures including dimples, inverted pyramids, and cones. The structures are compared in an optical model using a 20 m thick Si slab. I find that the light trapping potential differs between the structures, that the unit cell dimensions for the given structure is more important for light trapping than the type of structure, and that the optimum lattice period does not differ significantly between the different structures. The light-trapping effect of the structures is investigated as a function on incidence angle. The structures provide good light trapping also under angles of incidence up to 60 degrees. The behavior

Fundamental limit of light trapping in grating structures

KAUST Repository

Yu, Zongfu

2010-08-11

We use a rigorous electromagnetic approach to analyze the fundamental limit of light-trapping enhancement in grating structures. This limit can exceed the bulk limit of 4n 2, but has significant angular dependency. We explicitly show that 2D gratings provide more enhancement than 1D gratings. We also show the effects of the grating profile’s symmetry on the absorption enhancement limit. Numerical simulations are applied to support the theory. Our findings provide general guidance for the design of grating structures for light-trapping solar cells.

Fundamental limit of nanophotonic light trapping in solar cells.

Science.gov (United States)

Yu, Zongfu; Raman, Aaswath; Fan, Shanhui

2010-10-12

Establishing the fundamental limit of nanophotonic light-trapping schemes is of paramount importance and is becoming increasingly urgent for current solar cell research. The standard theory of light trapping demonstrated that absorption enhancement in a medium cannot exceed a factor of 4n(2)/sin(2)θ, where n is the refractive index of the active layer, and θ is the angle of the emission cone in the medium surrounding the cell. This theory, however, is not applicable in the nanophotonic regime. Here we develop a statistical temporal coupled-mode theory of light trapping based on a rigorous electromagnetic approach. Our theory reveals that the conventional limit can be substantially surpassed when optical modes exhibit deep-subwavelength-scale field confinement, opening new avenues for highly efficient next-generation solar cells.

Effects of carbaryl-bran bait on trap-catch and seed predation by ground beetles

Science.gov (United States)

Carbaryl-bran bait is effective against grasshoppers without many impacts on non-target organisms, but ground beetles (Coleoptera: Carabidae) may be susceptible to these baits. Carabids are beneficial in agricultural settings as predators of insect pests and weed seeds. Carabid species composition a...

Improving detection tools for emerald ash borer (Coleoptera: Buprestidae): comparison of multifunnel traps, prism traps, and lure types at varying population densities.

Science.gov (United States)

Crook, Damon J; Francese, Joseph A; Rietz, Michael L; Lance, David R; Hull-Sanders, Helen M; Mastro, Victor C; Silk, Peter J; Ryall, Krista L

2014-08-01

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a serious invasive pest of North American ash (Fraxinus spp.) that has caused devastating mortality since it was first identified in North America in 2002. In 2012, we conducted field trapping assays that tested the efficacy of purple prism and fluon-coated green multifunnel (Lindgren funnel) traps. Traps were baited with combinations of several lures that were previously shown to be attractive to A. planipennis: manuka oil--a sesquiterpene-rich oil, (3Z)-hexenol--a green leaf volatile, or (3Z)-dodecen-12-olide [= (3Z)-lactone], a sex pheromone. Eighty-nine blocks (trap lines) were tested throughout nine states along the outer edges of the currently known A. planipennis infestation in North America. Trap catch was highest on fluon-coated green multifunnel traps, and trap detections at sites with low A. planipennis population density ranged from 72 to 76% for all trap and lure types tested. (3Z)-hexenol and (3Z)-lactone baited traps functioned as well as (3Z)-hexenol and manuka oil-baited traps. Independent of the lure used, detection rates on green fluon-coated multifunnel traps were comparable with glued purple prism traps in areas with low A. planipennis population densities.

An Ingenious Super Light Trapping Surface Templated from Butterfly Wing Scales

Science.gov (United States)

Han, Zhiwu; Li, Bo; Mu, Zhengzhi; Yang, Meng; Niu, Shichao; Zhang, Junqiu; Ren, Luquan

2015-08-01

Based on the super light trapping property of butterfly Trogonoptera brookiana wings, the SiO2 replica of this bionic functional surface was successfully synthesized using a simple and highly effective synthesis method combining a sol-gel process and subsequent selective etching. Firstly, the reflectivity of butterfly wing scales was carefully examined. It was found that the whole reflectance spectroscopy of the butterfly wings showed a lower level (less than 10 %) in the visible spectrum. Thus, it was confirmed that the butterfly wings possessed a super light trapping effect. Afterwards, the morphologies and detailed architectures of the butterfly wing scales were carefully investigated using the ultra-depth three-dimensional (3D) microscope and field emission scanning electronic microscopy (FESEM). It was composed by the parallel ridges and quasi-honeycomb-like structure between them. Based on the biological properties and function above, an exact SiO2 negative replica was fabricated through a synthesis method combining a sol-gel process and subsequent selective etching. At last, the comparative analysis of morphology feature size and the reflectance spectroscopy between the SiO2 negative replica and the flat plate was conducted. It could be concluded that the SiO2 negative replica inherited not only the original super light trapping architectures, but also the super light trapping characteristics of bio-template. This work may open up an avenue for the design and fabrication of super light trapping materials and encourage people to look for more super light trapping architectures in nature.

Evaluation of the efficiency of various medfly female trapping combinations in Costa Rica in support of the sterile insect technique

International Nuclear Information System (INIS)

Camacho, H.

1999-01-01

This report contains information from a four-year research programme co-ordinated by the International Atomic Energy Agency. The objective of the programme was to develop a trapping system for females of the Mediterranean fruit fly (medfly), Ceratitis capitata (Diptera: Tephritidae), for practical use in Sterile Insect Technique (SIT) programs and to design and evaluate a trap to obtain eggs from wild female medflies in order to estimate sterility induction in the field population. The study was carried out at two different Agricultural Research Stations of the University of Costa Rica, the Fabio Baudrit Agricultural Research Station (FBS) and Laguna de Fraijanes Agricultural Research Station (LFS), and in a privately-owned coffee and orange plantation in Grecia canton (Coope-Victoria Farm). Female medfly attractants tested were three food based 'female' attractants (FA-3), namely ammonium acetate (AA), 1,4 diaminobutane (putrescine) and trimethylamine, all formulated to last at least one month. These attractants were evaluated either in combinations of two (AA + putrescine, termed FA-2) or all three (termed FA-3). The attractants were tested in various traps including the plastic International Pheromone's McPhail traps (IPMT) and Tephri traps, a Spanish trap similar to the IPMT. Traps were used either as a dry trap (provided with DDVP) or a wet trap (provided with water and 0.01% surfactant). Jackson traps with Trimedlure (JT,TML), a routinely used male medfly trapping system, was also used. Trapping experiments conducted in the citrus plantation of the FBS resulted in the following fly/trap/day indices (F/T/D): 7.18 with JT,TML; 4.62 with open bottom dry traps (OBDT) baited with FA-3; 4.18 with OBDT (PVC) baited with FA-3; 7.73 with IPMT baited with FA-3, wet; 8.245 with IPMT baited with FA-3, dry; 5.27 with IPMT baited with NuLure; 4.79 with Tephri baited with FA-3, wet; and 5.42 with Tephri, FA-3, dry. The F/T/D indices at the Coope-Victoria Farm, in coffee

Fundamental Limit of Nanophotonic Light-trapping in Solar Cells

OpenAIRE

Yu, Zongfu; Raman, Aaswath; Fan, Shanhui

2010-01-01

Establishing the fundamental limit of nanophotonic light-trapping schemes is of paramount importance and is becoming increasingly urgent for current solar cell research. The standard theory of light trapping demonstrated that absorption enhancement in a medium cannot exceed a factor of 4n^2/ sin^2(\\theta), where n is the refractive index of the active layer, and \\theta is the angle of the emission cone in the medium surrounding the cell. This theory, however, is not applicable in the nanophot...

Implementing a spinosad-based local bait station to control Bactrocera cucurbitae (Diptera: Tephritidae) in high rainfall areas of Reunion Island.

Science.gov (United States)

Delpoux, Camille; Deguine, Jean-Philippe

2015-01-01

Three species of fruit flies cause serious damage to cucurbit crops on Reunion Island: Bactrocera cucurbitae (Diptera: Tephritidae) (Coquillett 1899), Dacus ciliatus (Loew 1901), and Dacus demmerezi (Bezzi 1917). To control them, a program of agroecological management of cucurbit flies has been implemented based on the application of Synéis-appât, especially spot sprays on corn borders. However, the high rainfall on Reunion Island limits the long-term efficiency of the bait; in addition, this method cannot be used for large chayote trellises, because corn borders cannot be planted around them. The aim of this study was to design a bait station adapted to prevailing conditions on Reunion Island. An 'umbrella trap' tested in Taiwan was used as a reference to compare its efficacy with our local bait station. Experiments were conducted in field cages on B. cucurbitae to test different characteristics of bait stations and to construct one using local materials. Results were validated in the field. The attractiveness of the bait station was related mainly to the color of the external surface, yellow being the most attractive color. The efficacy of the bait station with respect to fly mortality was found to be linked to the accessibility of the bait, and direct application of Synéis-appât on the bait station was found to be the most efficient. In the field, B. cucurbitae were more attracted to the local bait station than to the umbrella trap, while the two other fly species displayed equal attraction to both trap types. Our local bait station is a useful alternative to spot sprays of Synéis-appât and is now included in a local pest management program and is well accepted by farmers. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

The Electronic McPhail Trap

Directory of Open Access Journals (Sweden)

Ilyas Potamitis

2014-11-01

Full Text Available Certain insects affect cultivations in a detrimental way. A notable case is the olive fruit fly (Bactrocera oleae (Rossi, that in Europe alone causes billions of euros in crop-loss/per year. Pests can be controlled with aerial and ground bait pesticide sprays, the efficiency of which depends on knowing the time and location of insect infestations as early as possible. The inspection of traps is currently carried out manually. Automatic monitoring traps can enhance efficient monitoring of flying pests by identifying and counting targeted pests as they enter the trap. This work deals with the hardware setup of an insect trap with an embedded optoelectronic sensor that automatically records insects as they fly in the trap. The sensor responsible for detecting the insect is an array of phototransistors receiving light from an infrared LED. The wing-beat recording is based on the interruption of the emitted light due to the partial occlusion from insect’s wings as they fly in the trap. We show that the recordings are of high quality paving the way for automatic recognition and transmission of insect detections from the field to a smartphone. This work emphasizes the hardware implementation of the sensor and the detection/counting module giving all necessary implementation details needed to construct it.

Trapping of light by metal arrays

Science.gov (United States)

Khardikov, Vyacheslav V.; Iarko, Ekaterina O.; Prosvirnin, Sergey L.

2010-04-01

The problem of the near-IR light reflection from and transmittance through a planar 2D periodic metal-dielectric structure with a square periodic cell of two complex-shaped asymmetric metal elements has been solved. Conditions of the light confinement by excitation of the trapped mode resonances in certain structures, both polarization-sensitive and polarization-insensitive, were studied. For the first time, the existence of a high-order trapped mode resonance with the greater quality factor than that of the lowest one has been shown. It was ascertained that the Babinet principle provides a good prediction of the resonance properties of the complementary structures, despite the very high Joule losses in the metal strips in near-IR, a finite thickness of the metal elements and the presence of a dielectric substrate.

Trapping of light by metal arrays

International Nuclear Information System (INIS)

Khardikov, Vyacheslav V; Iarko, Ekaterina O; Prosvirnin, Sergey L

2010-01-01

The problem of the near-IR light reflection from and transmittance through a planar 2D periodic metal–dielectric structure with a square periodic cell of two complex-shaped asymmetric metal elements has been solved. Conditions of the light confinement by excitation of the trapped mode resonances in certain structures, both polarization-sensitive and polarization-insensitive, were studied. For the first time, the existence of a high-order trapped mode resonance with the greater quality factor than that of the lowest one has been shown. It was ascertained that the Babinet principle provides a good prediction of the resonance properties of the complementary structures, despite the very high Joule losses in the metal strips in near-IR, a finite thickness of the metal elements and the presence of a dielectric substrate

Captura de Rhynchophorus palmarum L. (Coleoptera: curculionidae em armadilhas iscadas com o feromônio de agregação e compostos voláteis de frutos do abacaxi Trap catches of Rhynchophorus palmarum L. (Coleoptera: curculionidae baited with its aggregation pheromone and volatile compounds from pineapple

Directory of Open Access Journals (Sweden)

Adriana Guimarães Duarte

2003-04-01

Full Text Available O objetivo deste trabalho foi determinar os índices de captura de Rhynchophorus palmarum em armadilhas iscadas com o feromônio de agregação, 6-metil-2(E-hepten-4-ol (rincoforol, associado a toletes de cana-de-açúcar, a pedaços de frutos do abacaxi e a seis compostos voláteis isolados de frutos do abacaxi. Os compostos voláteis do abacaxi são caracterizados por uma mistura de ésteres metílicos e etílicos, sendo o octanoato de metila e o octanoato de etila os mais abundantes. As armadilhas iscadas com o rincoforol associado a toletes de cana-de-açúcar e as iscas com rincoforol associado a pedaços de abacaxi não apresentaram diferenças significativas no número de besouros capturados. No entanto, ambas apresentaram índices de captura superiores àquelas em que o rincoforol foi utilizado em associação com voláteis do abacaxi. Não se observaram efeitos significativos do local e época de captura, nem no número de machos e de fêmeas capturados.The aim of this work was to investigate the capture of Rhynchophorus palmarum in traps baited with its aggregation pheromone, 6-methyl-2(E-hepten-4-ol (rhynchophorol, in association with sugar cane, pieces of pineapple fruit, and six volatile compounds from pineapple. A mixture of methyl and ethyl esters, being methyl octanoate and ethyl octanoate the most abundant, characterizes the volatile compounds from pineapple fruits. Traps baited with rhynchophorol in association with sugar cane and those baited with rhynchophorol in association with pieces of pineapple, showed no significant differences in the number of trapped weevils. However, both traps caught significantly more weevils, than those baited with rhynchophorol in association with pineapple volatiles. There were no significant effects from place and time or in the number of male and female weevils trapped.

Use of herring bait to farm lobsters in the Gulf of Maine.

Science.gov (United States)

Grabowski, Jonathan H; Clesceri, Erika J; Baukus, Adam J; Gaudette, Julien; Weber, Matthew; Yund, Philip O

2010-04-15

Ecologists, fisheries scientists, and coastal managers have all called for an ecosystem approach to fisheries management, yet many species such as the American lobster (Homarus americanus) are still largely managed individually. One hypothesis that has yet to be tested suggests that human augmentation of lobster diets via the use of Atlantic herring (Clupea harengus) as bait may contribute to recent increases in lobster landings. Currently 70% of Atlantic herring landings in the Gulf of Maine are used as bait to catch lobsters in traps throughout coastal New England. We examined the effects of this herring bait on the diet composition and growth rate of lobsters at heavily baited vs. seasonally closed (i.e., bait free) sites in coastal Maine. Our results suggest that human use of herring bait may be subsidizing juvenile lobster diets, thereby enhancing lobster growth and the overall economic value and yield of one of the most valuable fisheries in the U.S. Our study illustrates that shifting to an ecosystem approach to fisheries management should require consideration of cross-fishery interactions.

Use of herring bait to farm lobsters in the Gulf of Maine.

Directory of Open Access Journals (Sweden)

Jonathan H Grabowski

2010-04-01

Full Text Available Ecologists, fisheries scientists, and coastal managers have all called for an ecosystem approach to fisheries management, yet many species such as the American lobster (Homarus americanus are still largely managed individually. One hypothesis that has yet to be tested suggests that human augmentation of lobster diets via the use of Atlantic herring (Clupea harengus as bait may contribute to recent increases in lobster landings. Currently 70% of Atlantic herring landings in the Gulf of Maine are used as bait to catch lobsters in traps throughout coastal New England.We examined the effects of this herring bait on the diet composition and growth rate of lobsters at heavily baited vs. seasonally closed (i.e., bait free sites in coastal Maine. Our results suggest that human use of herring bait may be subsidizing juvenile lobster diets, thereby enhancing lobster growth and the overall economic value and yield of one of the most valuable fisheries in the U.S.Our study illustrates that shifting to an ecosystem approach to fisheries management should require consideration of cross-fishery interactions.

Field evaluation of a new light trap for phlebotomine sand flies.

Science.gov (United States)

Gaglio, Gabriella; Napoli, Ettore; Falsone, Luigi; Giannetto, Salvatore; Brianti, Emanuele

2017-10-01

Light traps are one of the most common attractive method for the collection of nocturnal insects. Although light traps are generally referred to as "CDC light traps", different models, equipped with incandescent or UV lamps, have been developed. A new light trap, named Laika trap 3.0, equipped with LED lamps and featured with a light and handy design, has been recently proposed into the market. In this study we tested and compared the capture performances of this new trap with those of a classical light trap model under field conditions. From May to November 2013, a Laika trap and a classical light trap were placed biweekly in an area endemic for sand flies. A total of 256 sand fly specimens, belonging to 3 species (Sergentomyia minuta, Phlebotomus perniciosus, Phlebotomus neglectus) were collected during the study period. The Laika trap captured 126 phlebotomine sand flies: P. perniciosus (n=38); S. minuta (n=88), a similar number of specimens (130) and the same species were captured by classical light trap which collected also 3 specimens of P. neglectus. No significant differences in the capture efficiency at each day of trapping, neither in the number of species or in the sex of sand flies were observed. According to results of this study, the Laika trap may be a valid alternative to classical light trap models especially when handy design and low power consumption are key factors in field studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Potential for the use of male pheromone components in female trapping: a progress report

International Nuclear Information System (INIS)

Howse, P.E.; Underwood, K.L.; Knapp, J.J.; Alemany Ferra, A.; Miranda, M.A.

1999-01-01

Experiments were conducted to determine if reducing the male population using TML traps and pheromone baited traps would enhance female Mediterranean fruit fly capture. Investigations were conducted in citrus plantations in Mallorca. In the first trial (0.36 ha, Son Coll Vey, Palma) Agrisense yellow delta traps were deployed on every third tree in adjacent rows. On each other tree, a TML bait was placed with an insecticide strip containing Dichlorvos. Thus, each of the delta traps was surrounded by a hexagon of TML + insecticide baited trees. The rationale of this experiment was to remove males from the vicinity of pheromone-baited traps and thereby increase the apparency of the female lure. Before the trial, male catches averaged 4.1 per day in TML traps. During the trial, this was reduced to approximately 0.6 males/trap/day. The traps with pheromone (pyrazines in various combinations and ratios) caught around 0.05 females/trap/day. The pheromone traps remained female selective, with a negligible male catch, similar to that in unbaited traps. The most likely cause for the very low female catch may be that insufficient males were removed by the lure and kill devices. In the second trial (0.67 ha, Inca, Mallorca) the proprietor had deployed 83 traps, baited with TML and insecticide, for 18 days prior to the placement of five treatments with six replicates. The delta traps were placed on every third tree, with replicates every third row. The female catch showed a progressive enhancement over a period of 6 weeks, reaching a level about six times that of males in TML traps. (author)

Notes on Apidae and Vespidae (Hymenoptera) Species Collected by Bait Traps in OrganicVineyard and Orchards of Kemalpaşa (İzmir), Western Turkey

OpenAIRE

ÜZÜM, Ahu; TANYERİ, Rukiye; GÜLPERÇİN, Nilay; TEZCAN, Serdar; YILDIRIM, Erol

2010-01-01

Hymenoptera species collected by bait traps during the months of June-October in organic vineyard and orchards in Kemalpaşa district, (İzmir) of Western Turkey were evaluated in this study. As a result, six species belonging 2007 to two families of Hymenoptera were determined. Those were Apis mellifera Linnaeus, 1758, Vespula germanica (Fabricius, 1793), Vespa crabro Linnaeus, 1758, Vespa orientalis Linnaeus, 1771, Polistes dominulus (Christ, 1791) and Polistes gallicus (Linnaeus, 1767). Amon...

Lightweight, Light-Trapped, Thin GaAs Solar Cells for Spacecraft Applications.

Science.gov (United States)

1995-10-05

improve the efficiency of this type of cell. 2 The high efficiency and light weight of the cover glass supported GaAs solar cell can have a significant...is a 3-mil cover glass and 1-mil silicone adhesive on the front surface of the GaAs solar cell. Power Output 3000 400 -{ 2400 { N 300 S18200 W/m2...the ultra-thin, light-trapped GaAs solar ceill 3. Incorporate light trapping. 0 external quantum efficiency at 850 nm increased by 5.2% 4. Develop

Effect of iron cation on geochemical trapping of CO2 in brine

Science.gov (United States)

Liu, Qi; Maroto-Valer, Mercedes

2014-05-01

Carbon dioxide sequestration using brines has emerged as a promising technology to mitigate the adverse impacts of climate change due to its large storage capacity and favorable chemistries. However, the permanent storage (mineral trapping) of CO2 in brines takes significantly long periods of time as the formation and precipitation of carbonates is very slow .[1]. The main parameters reported to effect on mineral trapping of CO2 sequestration in brines are brine composition, brine pH, system temperature and pressure.[2, 3]. It is suggested that the precipitation of mineral carbonates is mostly dependent on brine pH. Previous studies by the authors concluded that iron in natural brines causes pH instability, but it was not ascertained whether ferric iron or ferrous iron caused pH instability .[4]. Accordingly, the aim of this project is to study synthetic brines mimicking the major ions found in natural brines and including different concentrations of ferric and ferrous iron. Three brines were prepared, as follows: Brine 1 was prepared with ferric Fe3+ iron, Brine 2 prepared with ferrous Fe2+ iron and Brine 3 prepared with no iron. A series of pH stability studies and carbonation reactions were conducted using the above three brines. It is concluded that the ferrous iron causes pH instability, while ferric iron might promote carbonate precipitation. .1. Garcia, S., et al., Sequestration of non-pure carbon dioxide streams in iron oxyhydroxide-containing saline repositories. International Journal of Greenhouse Gas Control, 2012. 7: p. 89-97. 2. Liu, Q. and M.M. Maroto-Valer, Investigation of the pH effect of a typical host rock and buffer solution on CO 2 sequestration in synthetic brines. Fuel Processing Technology, 2010. 91(10): p. 1321-1329. 3. Liu, Q. and M.M. MarotoValer, Parameters affecting mineral trapping of CO2 sequestration in brines. Greenhouse Gases: Science and Technology, 2011. 1(3): p. 211-222. 4. Druckenmiller, M.L. and M.M. Maroto-Valer, Carbon

Effectiveness of odor-baited trap trees for plum curculio (Coleoptera: Curculionidae) monitoring in commercial apple orchards in the northeast.

Science.gov (United States)

Piñero, Jaime C; Agnello, Arthur M; Tuttle, Arthur; Leskey, Tracy C; Faubert, Heather; Koehler, Glen; Los, Lorraine; Morin, Glenn; Leahy, Kathleen; Cooley, Daniel R; Prokopy, Ronald J

2011-10-01

The plum curculio, Conotrachelus nenuphar (Herbst), is a key pest of pome and stone fruit in eastern and central North America. For effective management of this insect pest in commercial apple (Malus spp.) orchards in the northeastern United States and Canada, one of the greatest challenges has been to determine the need for and timing of insecticide applications that will protect apple fruit from injury by adults. In a 2004-2005 study, we assessed the efficacy and economic viability of a reduced-risk integrated pest management strategy involving an odor-baited trap tree approach to determine need for and timing of insecticide use against plum curculio based on appearance of fresh egg-laying scars. Evaluations took place in commercial apple orchards in seven northeastern U.S. states. More specifically, we compared the trap-tree approach with three calendar-driven whole-block sprays and with heat-unit accumulation models that predict how long insecticide should be applied to orchard trees to prevent injury by plum curculio late in the season. Trap tree plots received a whole-plot insecticide spray by the time of petal fall, and succeeding sprays (if needed) were applied to peripheral-row trees only, depending on a threshold of one fresh plum curculio egg-laying scar out of 25 fruit sampled from a single trap tree. In both years, level of plum curculio injury to fruit sampled from perimeter-row, the most interior-row trees and whole-plot injury in trap tree plots did not differ significantly from that recorded in plots subject to conventional management or in plots managed using the heat-unit accumulation approach. The amount of insecticide used in trap tree plots was reduced at least by 43% compared with plots managed with the conventional approach. Advantages and potential pitfalls of the bio-based trap tree approach to plum curculio monitoring in apple orchards are discussed.

Optimal wavelength scale diffraction gratings for light trapping in solar cells

International Nuclear Information System (INIS)

Chong, Teck Kong; Wilson, Jonathan; Mokkapati, Sudha; Catchpole, Kylie R

2012-01-01

Dielectric gratings are a promising method of achieving light trapping for thin crystalline silicon solar cells. In this paper, we systematically examine the potential performance of thin silicon solar cells with either silicon (Si) or titanium dioxide (TiO 2 ) gratings using numerical simulations. The square pyramid structure with silicon nitride coating provides the best light trapping among all the symmetric structures investigated, with 89% of the expected short circuit current density of the Lambertian case. For structures where the grating is at the rear of the cell, we show that the light trapping provided by the square pyramid and the checkerboard structure is almost identical. Introducing asymmetry into the grating structures can further improve their light trapping properties. An optimized Si skewed pyramid grating on the front surface of the solar cell results in a maximum short circuit current density, J sc , of 33.4 mA cm −2 , which is 91% of the J sc expected from an ideal Lambertian scatterer. An optimized Si skewed pyramid grating on the rear performs as well as a rear Lambertian scatterer and an optimized TiO 2 grating on the rear results in 84% of the J sc expected from an optimized Si grating. The results show that submicron symmetric and skewed pyramids of Si or TiO 2 are a highly effective way of achieving light trapping in thin film solar cells. TiO 2 structures would have the additional advantage of not increasing recombination within the cell. (paper)

Verification of geomechanical integrity and prediction of long-term mineral trapping for the Ketzin CO2 storage pilot site

Science.gov (United States)

Kempka, Thomas; De Lucia, Marco; Kühn, Michael

2014-05-01

Static and dynamic numerical modelling generally accompany the entire CO2 storage site life cycle. Thereto, it is required to match the employed models with field observations on a regular basis in order to predict future site behaviour. We investigated the coupled processes at the Ketzin CO2 storage pilot site [1] using a model coupling concept focusing on the temporal relevance of processes involved (hydraulic, chemical and mechanical) at given time-scales (site operation, abandonment and long-term stabilization). For that purpose, long-term dynamic multi-phase flow simulations [2], [3] established the basis for all simulations discussed in the following. Hereby, pressure changes resulting in geomechanical effects are largest during site operation, whereas geochemical reactions are governed by slow kinetics resulting in a long-term stabilization. To account for mechanical integrity, which may be mainly affected during site operation, we incorporated a regional-scale coupled hydro-mechanical model. Our simulation results show maximum ground surface displacements of about 4 mm, whereas shear and tensile failure are not observed. Consequently, the CO2 storage operation at the Ketzin pilot site does not compromise reservoir, caprock and fault integrity. Chemical processes responsible for mineral trapping are expected to mainly occur during long-term stabilization at the Ketzin pilot site [4]. Hence, our previous assessment [3] was extended by integrating two long-term mineral trapping scenarios. Thereby, mineral trapping contributes to the trapping mechanisms with 11.7 % after 16,000 years of simulation in our conservative and with 30.9 % in our maximum reactivity scenarios. Dynamic flow simulations indicate that only 0.2 % of the CO2 injected (about 67,270 t CO2 in total) is in gaseous state, but structurally trapped after 16,000 years. Depending on the studied long-term scenario, CO2 dissolution is the dominating trapping mechanism with 68.9 % and 88

Numerical modeling of injection and mineral trapping of CO2 withH2S and SO2 in a Sandstone Formation

Energy Technology Data Exchange (ETDEWEB)

Xu, Tianfu; Apps, John A.; Pruess, Karsten; Yamamoto, Hajime

2004-09-07

Carbon dioxide (CO{sub 2}) injection into deep geologic formations could decrease the atmospheric accumulation of this gas from anthropogenic sources. Furthermore, by co-injecting H{sub 2}S or SO{sub 2}, the products respectively of coal gasification or combustion, with captured CO{sub 2}, problems associated with surface disposal would be mitigated. We developed models that simulate the co-injection of H{sub 2}S or SO{sub 2} with CO{sub 2} into an arkose formation at a depth of about 2 km and 75 C. The hydrogeology and mineralogy of the injected formation are typical of those encountered in Gulf Coast aquifers of the United States. Six numerical simulations of a simplified 1-D radial region surrounding the injection well were performed. The injection of CO{sub 2} alone or co-injection with SO{sub 2} or H{sub 2}S results in a concentrically zoned distribution of secondary minerals surrounding a leached and acidified region adjacent to the injection well. Co-injection of SO{sub 2} with CO{sub 2} results in a larger and more strongly acidified zone, and alteration differs substantially from that caused by the co-injection of H{sub 2}S or injection of CO{sub 2} alone. Precipitation of carbonates occurs within a higher pH (pH > 5) peripheral zone. Significant quantities of CO{sub 2} are sequestered by ankerite, dawsonite, and lesser siderite. The CO{sub 2} mineral-trapping capacity of the formation can attain 40-50 kg/m{sup 3} medium for the selected arkose. In contrast, secondary sulfates precipitate at lower pH (pH < 5) within the acidified zone. Most of the injected SO{sub 2} is transformed and immobilized through alunite precipitation with lesser amounts of anhydrite and minor quantities of pyrite. The dissolved CO{sub 2} increases with time (enhanced solubility trapping). The mineral alteration induced by injection of CO{sub 2} with either SO{sub 2} or H{sub 2}S leads to corresponding changes in porosity. Significant increases in porosity occur in the acidified

BAITS FOR MONITORING WEEVILS IN BANANA PLANTATION OF VARIETY CV. NANICÃO

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J. N. Corassa

2018-02-01

Full Text Available Cosmopolites sordidus (Germar, 1824 (Coleoptera: Curculionidae and Metamasius hemipterus (Linnaeus, 1758 (Coleoptera: Curculionidae are the main beetles associated with banana plants in Brazil. The objective of this study was to evaluate the effect of attractive traps for monitoring these beetles, from May to September 2012 (hot season and October 2012 to April 2013 (rainy season, in the Amazon biome conditions. The experiment was installed in commercial banana plantations that produce the banana variety cv. Nanicão, divided into three plots of 0.5 hectare each, assessing the following treatments: 1 synthetic aggregation pheromone for the species C. sordidus (control; 2 molasses sugarcane and; 3 sugarcane oarlock. It was found that the three baits showed similar behavior in the hot and rainy season, with the highest catch of C. sordidus in the rainy season. The molasses sugarcane and sugarcane oarlock did not show efficiency in the capture of C. sordidus. Attractive bait sugarcane oarlock, in pitfall trap, proved efficient for both monitoring and mass collect M. hemipterus in banana plantations.

3D-Printed external light traps for solar cells

NARCIS (Netherlands)

van Dijk, L.; Paetzold, U.W.; Blab, Gerhard; Marcus, E.A.P.; Oostra, A.J.; van de Groep, J.; Polman, A.; Schropp, R.E.I.; Di Vece, M.

2015-01-01

We demonstrate a universally applicable 3D-printed external light trap for solar cells. We placed a macroscopic external light trap made of smoothened, silver coated plastic at the sun-facing surface of different types of solar cells. The trap consists of a reflective parabolic concentrator on top

Evaluation of Methods for Sampling the Malaria Vector Anopheles darlingi (Diptera, Culicidae) in Suriname and the Relation With Its Biting Behavior

NARCIS (Netherlands)

Hiwat-van Laar, H.; Rijk, de M.; Andriessen, R.; Koenraadt, C.J.M.; Takken, W.

2011-01-01

The effectiveness of CO2-baited and human-baited mosquito traps for the sampling of Anopheles darlingi Root was evaluated and compared with human landing collections in Suriname. Biting preferences of this mosquito on a human host were studied and related to trapping data. Traps used were the

Poultry egg components as cereal bait additives for enhancing rodenticide based control success and trap index of house rat, Rattus rattus

Directory of Open Access Journals (Sweden)

Neena Singla

2014-05-01

Conclusions: Present data support the use of 2% egg albumin and egg shell powder in cereal bait to enhance acceptance and efficacy of 2% zinc phosphide bait against R. rattus. This may further help in checking the spread of rodent borne diseases to animals and humans.

Exploration of external light trapping for photovoltaic modules

NARCIS (Netherlands)

van Dijk, L.; van de Groep, J.; Di Vece, M.; Schropp, R.E.I.

2016-01-01

The reflection of incident sunlight by photovoltaic modules prevents them from reaching their theoretical energy conversion limit. We explore the effectiveness of a universal external light trap that can tackle this reflection loss. A unique feature of external light traps is their capability to

Development of a Bait System for the Pharaoh's Ant, Monomorium ...

African Journals Online (AJOL)

The infestation of the Pharaoh's ant, Monomorium pharaonis L. is widespread and, sometimes, very serious in homes, hospitals, restaurants, factories, etc. People are helpless because effective baited traps are not available locally, and little has been done locally to develop effective control strategies for these ants.

Disorder improves nanophotonic light trapping in thin-film solar cells

Energy Technology Data Exchange (ETDEWEB)

Paetzold, U. W., E-mail: u.paetzold@fz-juelich.de; Smeets, M.; Meier, M.; Bittkau, K.; Merdzhanova, T.; Smirnov, V.; Carius, R.; Rau, U. [IEK5—Photovoltaik, Forschungszentrum Jülich GmbH, 52425 Jülich (Germany); Michaelis, D.; Waechter, C. [Fraunhofer Institut für Angewandte Optik und Feinmechanik, Albert Einstein Str. 7, D-07745 Jena (Germany)

2014-03-31

We present a systematic experimental study on the impact of disorder in advanced nanophotonic light-trapping concepts of thin-film solar cells. Thin-film solar cells made of hydrogenated amorphous silicon were prepared on imprint-textured glass superstrates. For periodically textured superstrates of periods below 500 nm, the nanophotonic light-trapping effect is already superior to state-of-the-art randomly textured front contacts. The nanophotonic light-trapping effect can be associated to light coupling to leaky waveguide modes causing resonances in the external quantum efficiency of only a few nanometer widths for wavelengths longer than 500 nm. With increasing disorder of the nanotextured front contact, these resonances broaden and their relative altitude decreases. Moreover, overall the external quantum efficiency, i.e., the light-trapping effect, increases incrementally with increasing disorder. Thereby, our study is a systematic experimental proof that disorder is conceptually an advantage for nanophotonic light-trapping concepts employing grating couplers in thin-film solar cells. The result is relevant for the large field of research on nanophotonic light trapping in thin-film solar cells which currently investigates and prototypes a number of new concepts including disordered periodic and quasi periodic textures.

Exceptionally High Efficient Co-Co2P@N, P-Codoped Carbon Hybrid Catalyst for Visible Light-Driven CO2-to-CO Conversion.

Science.gov (United States)

Fu, Wen Gan

2018-05-02

Artificial photosynthesis has attracted wide attention, particularly the development of efficient solar light-driven methods to reduce CO2 to form energy-rich carbon-based products. Because CO2 reduction is an uphill process with a large energy barrier, suitable catalysts are necessary to achieve this transformation. In addition, CO2 adsorption on a catalyst and proton transfer to CO2 are two important factors for the conversion reaction，and catalysts with high surface area and more active sites are required to improve the efficiency of CO2 reduction. Here, we report a visible light-driven system for CO2-to-CO conversion that consists of a heterogeneous hybrid catalyst of Co and Co2P nanoparticles embedded in carbon nanolayers codoped with N and P (Co-Co2P@NPC) and a homogeneous Ru(II)-based complex photosensitizer. The average generation rate of CO of the system was up to 35,000 μmol h-1 g-1 with selectivity of 79.1% in 3 h. Linear CO production at an exceptionally high rate of 63,000 μmol h-1 g-1 was observed in the first hour of reaction. Inspired by this highly active catalyst, we also synthesized Co@NC and Co2P@NPC materials and explored their structure, morphology, and catalytic properties for CO2 photoreduction. The results showed that the nanoparticle size, partially adsorbed H2O molecules on the catalyst surface, and the hybrid nature of the systems influenced their photocatalytic CO2 reduction performance. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Control of zoonotic cutaneous leishmaniasis vector, Phlebotomus papatasi, using attractive toxic sugar baits (ATSB.

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Abedin Saghafipour

Full Text Available Attractive Toxic Sugar Baits (ATSB is a new vector control method that meets Integrated Vector Management (IVM goals. In an experimental design, this study aimed to determine effects of ATSB on control of Phlebotomus papatasi, as a main vector of Zoonotic Cutaneous Leishmaniasis (ZCL, in Qom Province, center of Iran.In a cross-sectional design, boric acid was mixed with brown sugar solution and tested as toxic baits for P. papatasi. Two methods were utilized to use the baits: (a spraying ATSB on vegetation, bushes, and shrubs; and (b setting ATSB-treated barrier fences in front of colonies at 500 m distance from the houses in outskirts of villages. In order to examine the residual efficacy rate of ATSB-treated barrier fences, the bioassay test was used. Density of P. papatasi sandflies was measured using sticky and light traps biweekly. For data analysis, Mann-Whitney U Test and Kruskal-Wallis were used. Results ATSB-treated barrier fences led to 3 times reduction in P. papatasi population. Besides that, ATSB spraying on plants led to more than 5 times reduction in P. papatasi population.Comparing the incidence of leishmaniasis in treated villages before and after the study showed that the incidence was statistically reduced. Therefore, ATSB is an effective method to control vectors and prevent leishmaniasis.

Disorder Improves Light Absorption in Thin Film Silicon Solar Cells with Hybrid Light Trapping Structure

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Yanpeng Shi

2016-01-01

Full Text Available We present a systematic simulation study on the impact of disorder in thin film silicon solar cells with hybrid light trapping structure. For the periodical structures introducing certain randomness in some parameters, the nanophotonic light trapping effect is demonstrated to be superior to their periodic counterparts. The nanophotonic light trapping effect can be associated with the increased modes induced by the structural disorders. Our study is a systematic proof that certain disorder is conceptually an advantage for nanophotonic light trapping concepts in thin film solar cells. The result is relevant to the large field of research on nanophotonic light trapping which currently investigates and prototypes a number of new concepts including disordered periodic and quasiperiodic textures. The random effect on the shape of the pattern (position, height, and radius investigated in this paper could be a good approach to estimate the influence of experimental inaccuracies for periodic or quasi-periodic structures.

Impacts of CO2 Enrichment on Productivity and Light Requirements of Eelgrass.

Science.gov (United States)

Zimmerman, R. C.; Kohrs, D. G.; Steller, D. L.; Alberte, R. S.

1997-10-01

Seagrasses, although well adapted for submerged existence, are CO2-limited and photosynthetically inefficient in seawater. This leads to high light requirements for growth and survival and makes seagrasses vulnerable to light limitation. We explored the long-term impact of increased CO2 availability on light requirements, productivity, and C allocation in eelgrass (Zostera marina L.). Enrichment of seawater CO2 increased photosynthesis 3-fold, but had no long-term impact on respiration. By tripling the rate of light-saturated photosynthesis, CO2 enrichment reduced the daily period of irradiance-saturated photosynthesis (Hsat) that is required for the maintenance of positive whole-plant C balance from 7 to 2.7 h, allowing plants maintained under 4 h of Hsat to perform like plants growing in unenriched seawater with 12 h of Hsat. Eelgrass grown under 4 h of Hsat without added CO2 consumed internal C reserves as photosynthesis rates and chlorophyll levels dropped. Growth ceased after 30 d. Leaf photosynthesis, respiration, chlorophyll, and sucrose-phosphate synthase activity of CO2-enriched plants showed no acclimation to prolonged enrichment. Thus, the CO2-stimulated improvement in photosynthesis reduced light requirements in the long term, suggesting that globally increasing CO2 may enhance seagrass survival in eutrophic coastal waters, where populations have been devastated by algal proliferation and reduced water-column light transparency.

Visible light photoreduction of CO.sub.2 using heterostructured catalysts

Science.gov (United States)

Matranga, Christopher; Thompson, Robert L; Wang, Congjun

2015-03-24

The method provides for use of sensitized photocatalyst for the photocatalytic reduction of CO.sub.2 under visible light illumination. The photosensitized catalyst is comprised of a wide band gap semiconductor material, a transition metal co-catalyst, and a semiconductor sensitizer. The semiconductor sensitizer is photoexcited by visible light and forms a Type II band alignment with the wide band gap semiconductor material. The wide band gap semiconductor material and the semiconductor sensitizer may be a plurality of particles, and the particle diameters may be selected to accomplish desired band widths and optimize charge injection under visible light illumination by utilizing quantum size effects. In a particular embodiment, CO.sub.2 is reduced under visible light illumination using a CdSe/Pt/TiO2 sensitized photocatalyst with H.sub.2O as a hydrogen source.

The cultivation bias: different communities of arbuscular mycorrhizal fungi detected in roots from the field, from bait plants transplanted to the field, and from a greenhouse trap experiment.

Science.gov (United States)

Sýkorová, Zuzana; Ineichen, Kurt; Wiemken, Andres; Redecker, Dirk

2007-12-01

The community composition of arbuscular mycorrhizal fungi (AMF) was investigated in roots of four different plant species (Inula salicina, Medicago sativa, Origanum vulgare, and Bromus erectus) sampled in (1) a plant species-rich calcareous grassland, (2) a bait plant bioassay conducted directly in that grassland, and (3) a greenhouse trap experiment using soil and a transplanted whole plant from that grassland as inoculum. Roots were analyzed by AMF-specific nested polymerase chain reaction, restriction fragment length polymorphism screening, and sequence analyses of rDNA small subunit and internal transcribed spacer regions. The AMF sequences were analyzed phylogenetically and used to define monophyletic phylotypes. Overall, 16 phylotypes from several lineages of AMF were detected. The community composition was strongly influenced by the experimental approach, with additional influence of cultivation duration, substrate, and host plant species in some experiments. Some fungal phylotypes, e.g., GLOM-A3 (Glomus mosseae) and several members of Glomus group B, appeared predominantly in the greenhouse experiment or in bait plants. Thus, these phylotypes can be considered r strategists, rapidly colonizing uncolonized ruderal habitats in early successional stages of the fungal community. In the greenhouse experiment, for instance, G. mosseae was abundant after 3 months, but could not be detected anymore after 10 months. In contrast, other phylotypes as GLOM-A17 (G. badium) and GLOM-A16 were detected almost exclusively in roots sampled from plants naturally growing in the grassland or from bait plants exposed in the field, indicating that they preferentially occur in late successional stages of fungal communities and thus represent the K strategy. The only phylotype found with high frequency in all three experimental approaches was GLOM A-1 (G. intraradices), which is known to be a generalist. These results indicate that, in greenhouse trap experiments, it is difficult

An experimental study of relative permeability hysteresis, capillary trapping characteristics, and capillary pressure of CO2/brine systems at reservoir conditions

Science.gov (United States)

Akbarabadi, Morteza

We present the results of an extensive experimental study on the effects of hysteresis on permanent capillary trapping and relative permeability of CO2/brine and supercritical (sc)CO2+SO2/brine systems. We performed numerous unsteady- and steady-state drainage and imbibition full-recirculation flow experiments in three different sandstone rock samples, i.e., low and high-permeability Berea, Nugget sandstones, and Madison limestone carbonate rock sample. A state-of-the-art reservoir conditions core-flooding system was used to perform the tests. The core-flooding apparatus included a medical CT scanner to measure in-situ saturations. The scanner was rotated to the horizontal orientation allowing flow tests through vertically-placed core samples with about 3.8 cm diameter and 15 cm length. Both scCO2 /brine and gaseous CO2 (gCO2)/brine fluid systems were studied. The gaseous and supercritical CO2/brine experiments were carried out at 3.46 and 11 MPa back pressures and 20 and 55°C temperatures, respectively. Under the above-mentioned conditions, the gCO2 and scCO2 have 0.081 and 0.393 gr/cm3 densities, respectively. During unsteady-state tests, the samples were first saturated with brine and then flooded with CO2 (drainage) at different maximum flow rates. The drainage process was then followed by a low flow rate (0.375 cm 3/min) imbibition until residual CO2 saturation was achieved. Wide flow rate ranges of 0.25 to 20 cm3/min for scCO2 and 0.125 to 120 cm3min for gCO2 were used to investigate the variation of initial brine saturation (Swi) with maximum CO2 flow rate and variation of trapped CO2 saturation (SCO2r) with Swi. For a given Swi, the trapped scCO2 saturation was less than that of gCO2 in the same sample. This was attributed to brine being less wetting in the presence of scCO2 than in the presence of gCO 2. During the steady-state experiments, after providing of fully-brine saturated core, scCO2 was injected along with brine to find the drainage curve and as

Field Trapping Bactrocera latifrons (Diptera: Tephritidae with Select Eugenol Analogs That Have Been Found to Attract Other ‘Non-Responsive’ Fruit Fly Species

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Grant T. McQuate

2018-05-01

Full Text Available Bactrocera latifrons (Hendel (Diptera: Tephritidae is a pest fruit fly species native to Oriental Asia which has invaded and established in Hawaii and Tanzania and has been recovered in detection trapping in California. It is largely non-responsive to the male lures cuelure and methyl eugenol. Alpha-ionol + cade oil is a moderately effective male B. latifrons attractant, but is not as attractive as cuelure or methyl eugenol are to other fruit fly species. An improved attractant is therefore desired. With the recent success in finding other non-responsive fruit fly species attracted to isoeugenol, methyl-isoeugenol, or dihydroeugenol in Australia and other countries, we wanted to assess whether B. latifrons might also respond to these “eugenol analogs.” Working with wild B. latifrons populations in Hawaii, we assessed the relative catch of B. latifrons in traps baited with the eugenol analogs with catch in traps baited with alpha-ionol, alpha-ionol + cade oil, or alpha-ionol + eugenol. Catch was significantly higher in traps baited with alpha-ionol + cade oil relative to traps with any of the other baits. There was, though, some male B. latifrons catch in traps baited with dihydroeugenol or isoeugenol but none in traps baited with methyl-isoeugenol.

Optimization of Pheromone Traps for Coryphodema tristis (Lepidoptera: Cossidae).

Science.gov (United States)

Bouwer, Marc Clement; Slippers, Bernard; Wingfield, Michael John; Allison, Jeremy Dean; Rohwer, Egmont Richard

2017-08-01

The Coryphodema tristis (Drury) is an important pest of Eucalyptus nitens (Deane and Maiden) plantations in South Africa. The gregarious larvae of this pest cause damage by feeding on the tree sapwood, and adults emerge in spring each year. The aim of this study was to optimize pheromone traps for operational use in management programs. This was achieved by investigating different pheromone blend combinations and trap types for efficacy under field conditions. Our results confirm that the cross vane bucket funnel trap baited with a 95:2.5:2.5 volumetric blend of Z9-14:OAc, Z9-14:OH, and 14Ac was superior to similarly baited standard bucket funnel and delta traps. We also estimated the release rate and ratios of the pheromone compounds loaded into an artificial permeation dispenser through solid-phase microextraction sampling. Results showed that the released blend of pheromone compounds mirrored the dispensed ratios relatively accurately and that release rates are affected by temperature. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Mediterranean fruit fly female attractant studies in support of the sterile insect technique: trapping experiments conducted on the island of Chios, Greece

International Nuclear Information System (INIS)

Katsoyannos, B.I.; Papadopoulos, N.T.; Kouloussis, N.A.

1999-01-01

This paper contains information on a four-year research programme co-ordinated by the International Atomic Energy Agency. The main objective of the programme was to develop a trapping system for females of the Mediterranean fruit fly (medfly), Ceratitis capitata (Diptera: Tephritidae), for practical use in Sterile Insect Technique (SIT) programs and to design and evaluate a trap to obtain eggs from wild female medflies in order to estimate sterility induction in the field population. The experiments were conducted from July to September 1994-1997 on the island of Chios, Greece, in citrus orchards with low to medium medfly populations. Different trap types and several trap treatments consisting of sex and food based attractants were tested, following a standard coordinated experimental protocol. The most extensively tested were three food based 'female' attractants (FA-3), namely ammonium acetate (AA), 1,4 diaminobutane (putrescine) and trimethylamine, all formulated in dispensers lasting one month. These attractants were evaluated in combinations of two (AA + putrescine, termed FA-2) or three (FA-3) dispensers in various traps, including dry (provided with DDVP) or wet (provided with water and 0.01% surfactant) plastic International Pheromone's McPhail traps (IPMT). Among the various traps and treatments tested, the most effective for medfly capture was the wet IPMT, baited with FA-3 attractants. This treatment captured predominantly females and was relatively selective for medflies. In dry IPMT traps, the FA-3 were as effective as the standard 300 ml aqueous solution of 9% of the protein NuLure and 3% borax, but much more medfly selective. Dry IPMT traps were also more selective than wet ones. FA-3 baited wet Tephri traps (a Spanish modification of the McPhail trap), performed somewhat poorer than IPMT traps. Other dry trap types tested were not effective. Additional experiments showed that certain insecticide formulations used in dry traps may have a repellent

Light-erasable embedded charge-trapping memory based on MoS2 for system-on-panel applications

Science.gov (United States)

He, Long-Fei; Zhu, Hao; Xu, Jing; Liu, Hao; Nie, Xin-Ran; Chen, Lin; Sun, Qing-Qing; Xia, Yang; Wei Zhang, David

2017-11-01

The continuous scaling and challenges in device integrations in modern portable electronic products have aroused many scientific interests, and a great deal of effort has been made in seeking solutions towards a more microminiaturized package assembled with smaller and more powerful components. In this study, an embedded light-erasable charge-trapping memory with a high-k dielectric stack (Al2O3/HfO2/Al2O3) and an atomically thin MoS2 channel has been fabricated and fully characterized. The memory exhibits a sufficient memory window, fast programming and erasing (P/E) speed, and high On/Off current ratio up to 107. Less than 25% memory window degradation is observed after projected 10-year retention, and the device functions perfectly after 8000 P/E operation cycles. Furthermore, the programmed device can be fully erased by incident light without electrical assistance. Such excellent memory performance originates from the intrinsic properties of two-dimensional (2D) MoS2 and the engineered back-gate dielectric stack. Our integration of 2D semiconductors in the infrastructure of light-erasable charge-trapping memory is very promising for future system-on-panel applications like storage of metadata and flexible imaging arrays.

A synthesized mating pheromone component increases adult sea lamprey (Petromyzon marinus) trap capture in management scenarios

Science.gov (United States)

Johnson, Nicholas S.; Siefkes, Michael J.; Wagner, C. Michael; Dawson, Heather; Wang, Huiyong; Steeves, Todd; Twohey, Michael; Li, Weiming

2013-01-01

Application of chemical cues to manipulate adult sea lamprey (Petromyzon marinus) behavior is among the options considered for new sea lamprey control techniques in the Laurentian Great Lakes. A male mating pheromone component, 7a,12a,24-trihydroxy-3-one-5a-cholan-24-sulfate (3kPZS), lures ovulated female sea lamprey upstream into baited traps in experimental contexts with no odorant competition. A critical knowledge gap is whether this single pheromone component influences adult sea lamprey behavior in management contexts containing free-ranging sea lampreys. A solution of 3kPZS to reach a final in-stream concentration of 10-12 mol·L-1 was applied to eight Michigan streams at existing sea lamprey traps over 3 years, and catch rates were compared between paired 3kPZS-baited and unbaited traps. 3kPZS-baited traps captured significantly more sexually immature and mature sea lampreys, and overall yearly trapping efficiency within a stream averaged 10% higher during years when 3kPZS was applied. Video analysis of a trap funnel showed that the likelihood of sea lamprey trap entry after trap encounter was higher when the trap was 3kPZS baited. Our approach serves as a model for the development of similar control tools for sea lamprey and other aquatic invaders.

Trap-assisted and Langevin-type recombination in organic light-emitting diodes

Science.gov (United States)

Wetzelaer, G. A. H.; Kuik, M.; Nicolai, H. T.; Blom, P. W. M.

2011-04-01

Trapping of charges is known to play an important role in the charge transport of organic semiconductors, but the role of traps in the recombination process has not been addressed. Here we show that the ideality factor of the current of organic light-emitting diodes (OLEDs) in the diffusion-dominated regime has a temperature-independent value of 2, which reveals that nonradiative trap-assisted recombination dominates the current. In contrast, the ideality factor of the light output approaches unity, demonstrating that luminance is governed by recombination of the bimolecular Langevin type. This apparent contradiction can be resolved by measuring the current and luminance ideality factor for a white-emitting polymer, where both free and trapped charge carriers recombine radiatively. With increasing bias voltage, Langevin recombination becomes dominant over trap-assisted recombination due to its stronger dependence on carrier density, leading to an enhancement in OLED efficiency.

A comparison of two common flight interception traps to survey tropical arthropods

Directory of Open Access Journals (Sweden)

Greg Lamarre

2012-08-01

Full Text Available Tropical forests are predicted to harbor most of the insect diversity on earth, but few studies have been conducted to characterize insect communities in tropical forests. One major limitation is the lack of consensus on methods for insect collection. Deciding which insect trap to use is an important consideration for ecologists and entomologists, yet to date few study has presented a quantitative comparison of the results generated by standardized methods in tropical insect communities. Here, we investigate the relative performance of two flight interception traps, the windowpane trap, and the more widely used malaise trap, across a broad gradient of lowland forest types in French Guiana. The windowpane trap consistently collected significantly more Coleoptera and Blattaria than the malaise trap, which proved most effective for Diptera, Hymenoptera, and Hemiptera. Orthoptera and Lepidoptera were not well represented using either trap, suggesting the need for additional methods such as bait traps and light traps. Our results of contrasting trap performance among insect orders underscore the need for complementary trapping strategies using multiple methods for community surveys in tropical forests.

The range of attraction for light traps catching Culicoides biting midges (Diptera: Ceratopogonidae).

Science.gov (United States)

Kirkeby, Carsten; Græsbøll, Kaare; Stockmarr, Anders; Christiansen, Lasse E; Bødker, René

2013-03-15

Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light traps. Here we test a previously described mathematical model (Model I) and two novel models for the attraction of vectors to light traps (Model II and III). In Model I, Culicoides fly to the nearest trap from within a fixed range of attraction. In Model II Culicoides fly towards areas with greater light intensity, and in Model III Culicoides evaluate light sources in the field of view and fly towards the strongest. Model II and III incorporated the directionally dependent light field created around light traps with fluorescent light tubes. All three models were fitted to light trap collections obtained from two novel experimental setups in the field where traps were placed in different configurations. Results showed that overlapping ranges of attraction of neighboring traps extended the shared range of attraction. Model I did not fit data from any of the experimental setups. Model II could only fit data from one of the setups, while Model III fitted data from both experimental setups. The model with the best fit, Model III, indicates that Culicoides continuously evaluate the light source direction and intensity. The maximum range of attraction of a single 4W CDC light trap was estimated to be approximately 15.25 meters. The attraction towards light traps is different from the attraction to host animals and thus light trap catches may not represent the vector species and numbers attracted to hosts.

High CO/sub 2/ partial pressure effects on dark and light CO/sub 2/ fixation and metabolism in Vicia faba leaves

Energy Technology Data Exchange (ETDEWEB)

Coudret, A.; Ferron, F.; Laffray, D.

1985-01-01

Stomatal opening on Vicia faba can be induced by high CO/sub 2/ partial pressures (10.2%) in dark as well as in light. Stomatal aperture was measured in both cases with a hydrogen porometer. The distribution of /sup 14/C among early products of photosynthesis was studied. Comparisons are made with carboxylations occurring when stomata were open in the dark with CO/sub 2/-free air and in light with 0.034% CO/sub 2/. Results showed that in high CO/sub 2/ partial pressure in light, less radioactivity was incorporated in Calvin cycle intermediates and more in sucrose. ..beta.. carboxylations and photorespiration seemed to be inhibited. In the dark in both CO/sub 2/ conditions, /sup 14/C incorporation was found in malate and aspartate but also in serine and glycerate in high CO/sub 2/ conditions. In light these changes in metabolic pathways may be related with the deleterious effects recorded on leaves after long-term expositions to high partial pressure of CO/sub 2/.

The range of attraction for light traps catching Culicoides biting midges (Diptera: Ceratopogonidae)

DEFF Research Database (Denmark)

Kirkeby, Carsten; Græsbøll, Kaare; Stockmarr, Anders

2013-01-01

Background Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light tr...... light trap was estimated to be approximately 15.25 meters. The attraction towards light traps is different from the attraction to host animals and thus light trap catches may not represent the vector species and numbers attracted to hosts.......Background Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light...... traps. Methods Here we test a previously described mathematical model (Model I) and two novel models for the attraction of vectors to light traps (Model II and III). In Model I, Culicoides fly to the nearest trap from within a fixed range of attraction. In Model II Culicoides fly towards areas...

Cost effective flat plate photovoltaic modules using light trapping

Science.gov (United States)

Bain, C. N.; Gordon, B. A.; Knasel, T. M.; Malinowski, R. L.

1981-01-01

Work in optical trapping in 'thick films' is described to form a design guide for photovoltaic engineers. A thick optical film can trap light by diffusive reflection and total internal reflection. Light can be propagated reasonably long distances compared with layer thicknesses by this technique. This makes it possible to conduct light from inter-cell and intra-cell areas now not used in photovoltaic modules onto active cell areas.

CO2-Water-Rock Wettability: Variability, Influencing Factors, and Implications for CO2 Geostorage.

Science.gov (United States)

Iglauer, Stefan

2017-05-16

Carbon geosequestration (CGS) has been identified as a key technology to reduce anthropogenic greenhouse gas emissions and thus significantly mitigate climate change. In CGS, CO 2 is captured from large point-source emitters (e.g., coal fired power stations), purified, and injected deep underground into geological formations for disposal. However, the CO 2 has a lower density than the resident formation brine and thus migrates upward due to buoyancy forces. To prevent the CO 2 from leaking back to the surface, four trapping mechanisms are used: (1) structural trapping (where a tight caprock acts as a seal barrier through which the CO 2 cannot percolate), (2) residual trapping (where the CO 2 plume is split into many micrometer-sized bubbles, which are immobilized by capillary forces in the pore network of the rock), (3) dissolution trapping (where CO 2 dissolves in the formation brine and sinks deep into the reservoir due to a slight increase in brine density), and (4) mineral trapping (where the CO 2 introduced into the subsurface chemically reacts with the formation brine or reservoir rock or both to form solid precipitates). The efficiency of these trapping mechanisms and the movement of CO 2 through the rock are strongly influenced by the CO 2 -brine-rock wettability (mainly due to the small capillary-like pores in the rock which form a complex network), and it is thus of key importance to rigorously understand CO 2 -wettability. In this context, a substantial number of experiments have been conducted from which several conclusions can be drawn: of prime importance is the rock surface chemistry, and hydrophilic surfaces are water-wet while hydrophobic surfaces are CO 2 -wet. Note that CO 2 -wet surfaces dramatically reduce CO 2 storage capacities. Furthermore, increasing pressure, salinity, or dissolved ion valency increases CO 2 -wettability, while the effect of temperature is not well understood. Indeed theoretical understanding of CO 2 -wettability and the

Throwing new light on the reduction of CO2.

Science.gov (United States)

Ozin, Geoffrey A

2015-03-18

While the chemical energy in fossil fuels has enabled the rapid rise of modern civilization, their utilization and accompanying anthropogenic CO2 emissions is occurring at a rate that is outpacing nature's carbon cycle. Its effect is now considered to be irreversible and this could lead to the demise of human society. This is a complex issue without a single solution, yet from the burgeoning global research activity and development in the field of CO2 capture and utilization, there is light at the end of the tunnel. In this article a couple of recent advances are illuminated. Attention is focused on the discovery of gas-phase, light-assisted heterogeneous catalytic materials and processes for CO2 photoreduction that operate at sufficiently high rates and conversion efficiencies, and under mild conditions, to open a new pathway for an energy transition from today's "fossil fuel economy" to a new and sustainable "CO2 economy". Whichever of the competing CO2 capture and utilization approaches proves to be the best way forward for the development of a future CO2-based solar fuels economy, hopefully this can occur in a period short enough to circumvent the predicted adverse consequences of greenhouse gas climate change. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Light Trapping with Silicon Light Funnel Arrays

Directory of Open Access Journals (Sweden)

Ashish Prajapati

2018-03-01

Full Text Available Silicon light funnels are three-dimensional subwavelength structures in the shape of inverted cones with respect to the incoming illumination. Light funnel (LF arrays can serve as efficient absorbing layers on account of their light trapping capabilities, which are associated with the presence of high-density complex Mie modes. Specifically, light funnel arrays exhibit broadband absorption enhancement of the solar spectrum. In the current study, we numerically explore the optical coupling between surface light funnel arrays and the underlying substrates. We show that the absorption in the LF array-substrate complex is higher than the absorption in LF arrays of the same height (~10% increase. This, we suggest, implies that a LF array serves as an efficient surface element that imparts additional momentum components to the impinging illumination, and hence optically excites the substrate by near-field light concentration, excitation of traveling guided modes in the substrate, and mode hybridization.

Performance of yeast-baited traps with Triatoma sordida, Triatoma brasiliensis, Triatoma pseudomaculata, and Panstrongylus megistus in laboratory assays Rendimiento de trampas cebadas con levaduras en la captura de Triatoma sordida, Triatoma brasiliensis, Triatoma pseudomaculata y Panstrongylus megistus en experimentos de laboratorio

Directory of Open Access Journals (Sweden)

Herton H. R. Pires

2000-06-01

Full Text Available The effectiveness of a trap for triatomines baited with yeast cultures has been previously demonstrated for Triatoma infestans in laboratory assays. We report here results from laboratory assays testing yeast traps for Triatoma sordida, Triatoma brasiliensis, Triatoma pseudomaculata, and Panstrongylus megistus. All assays were conducted in an open experimental arena 100 cm X 100 cm, with two traps placed at opposite sides of the arena. One of the traps contained a yeast culture, and the other trap contained a saccharose solution as a control. Two series of experiments were done, one without a refuge for the insects and one with a refuge. The results obtained clearly demonstrated that the yeast-baited traps were effective in the laboratory in capturing both T. sordida and P. megistus. For T. sordida, yeast-baited traps captured significantly more bugs than did the control traps (t test P value = 0.03. For P. megistus, when a refuge was provided during the assay, yeast-baited traps also captured significantly more bugs than did the control traps (t test P value = 0.006. In the experiments with T. brasiliensis and T. pseudomaculata, both traps captured some insects, but the yeast traps captured many fewer bugs than was true with the T. sordida and P. megistus bugs. These results indicate that, in the laboratory, yeast traps can capture considerable numbers of T. sordida and P. megistus in one night. We discuss the potential use of yeast traps for detecting and capturing both triatomine species.Con anterioridad se ha demostrado la eficacia de las trampas cebadas con cultivos de levaduras (TCL para capturar Triatoma infestans en experimentos de laboratorio. En el presente estudio se describen los resultados obtenidos con estas trampas para capturar T. sordida, T. brasiliensis, T. pseudomaculata y Panstrongylus megistus, también en experimentos de laboratorio. Todos los experimentos fueron realizados en un recinto experimental abierto de 100 cm por

Photocatalytic oxidation removal of Hg"0 using ternary Ag/AgI-Ag_2CO_3 hybrids in wet scrubbing process under fluorescent light

International Nuclear Information System (INIS)

Zhang, Anchao; Zhang, Lixiang; Chen, Xiaozhuan; Zhu, Qifeng; Liu, Zhichao; Xiang, Jun

2017-01-01

Highlights: • Ag/AgI-Ag_2CO_3 hybrids were employed for Hg"0 removal under fluorescent light. • Superoxide radical (·O_2"−) played a key role in Hg"0 removal. • NO exhibited a significant effect on Hg"0 removal in comparison to SO_2. • The mechanism for enhanced Hg"0 removal over Ag/AgI-Ag_2CO_3 was proposed. - Abstract: A series of ternary Ag/AgI-Ag_2CO_3 photocatalysts synthesized using a facile coprecipitation method were employed to investigate their performances of Hg"0 removal in a wet scrubbing reactor. The hybrids were characterized by N_2 adsorption-desorption, XRD, SEM-EDS, HRTEM, XPS, DRS and ESR. The photocatalytic activities of Hg"0 removal were evaluated under fluorescent light. The results showed that AgI content, fluorescent light irradiation, reaction temperature all showed significant influences on Hg"0 removal. NO exhibited significant effect on Hg"0 removal in comparison to SO_2. Among these ternary Ag/AgI-Ag_2CO_3 hybrids, Ag/AgI(0.1)-Ag_2CO_3 showed the highest Hg"0 removal efficiency, which could be ascribed to the effective separation of photogenerated electron-hole pairs between AgI and Ag_2CO_3 and the surface plasmon resonance (SPR) effect in the visible region by metallic silver nanoparticles (Ag"0 NPs). The trapping studies of reactive radicals showed that the superoxide radicals (·O_2"−) may play a key role in Hg"0 removal under fluorescent light. According to the experimental and characterization results, a possible photocatalytic oxidation mechanism for enhanced Hg"0 removal over Ag/AgI(0.1)-Ag_2CO_3 hybrid under fluorescent light was proposed.

Variation in enantiospecific attraction of Ips avulsus (Coleoptera: Curculionidae) to the pheromone ipsdienol in Georgia.

Science.gov (United States)

Daniel Miller; Jeremy Allison

2011-01-01

In 2006, we tested the responses of the small southern pine engraver, Ips avulsus (Eichhoff) (Coleoptera: Curculionidae), to multiple-funnel traps baited with (+)-, (-)-, and (+/-)- ipsdienol. Three experiments were conducted in Georgia with all traps co-baited with one of the following lure combinations, respectively: experiment 1, ipsenol; experiment 2, lanierone and...

Comparison of sampling techniques for Rift Valley Fever virus potential vectors, Aedes aegypti and Culex pipiens complex, in Ngorongoro District in northern Tanzania.

Science.gov (United States)

Mweya, Clement N; Kimera, Sharadhuli I; Karimuribo, Esron D; Mboera, Leonard E G

2013-07-01

We investigated mosquito sampling techniques with two types of traps and attractants at different time for trapping potential vectors for Rift Valley Fever virus. The study was conducted in six villages in Ngorongoro district in Tanzania from September to October 2012. A total of 1814 mosquitoes were collected, of which 738 were collected by CDC light traps and 1076 by Mosquito Magnet trapping technique. Of the collected mosquitoes, 12.46% (N = 226) were Aedes aegypti and 87.54% (N = 1588) were Culex pipiens complex. More mosquitoes were collected outdoors using Mosquito Magnets baited with octenol attractant, 36.38% (N =660) followed by indoor trapping using CDC light traps without attractant, 29.60% (N = 537). Most of Ae. aegypti mosquitoes were collected outdoor using Mosquito Magnets, 95% (N = 214) whereas Cx. pipiens complex were trapped both indoor using CDC light traps without attractant and outdoors using both CDC light traps baited with carbon dioxide (CO2) sachets and Mosquito Magnets. Analysis on the differences in abundance of mosquitoes trapped by different techniques using Generalized Linear Models was statistically significance at p-value < 0.05 for both species. Three hours mosquito collections show differing patterns in activity, most Ae. aegypti species were collected primarily during the first and last quarters of the day. Cx pipiens complex was active throughout the night, early evening and early morning then decreased markedly during the day time. The results presented in this paper emphasize the possibility of using Mosquito Magnets in order to efficiently capture these potential RVF vectors.

Advanced methods for light trapping in optically thin silicon solar cells

Science.gov (United States)

Nagel, James Richard

2011-12-01

The field of light trapping is the study of how best to absorb light in a thin film of material when most light either reflects away at the surface or transmits straight through to the other side. This has tremendous application to the field of photovoltaics where thin silicon films can be manufactured cheaply, but also fail to capture all of the available photons in the solar spectrum. Advancements in light trapping therefore bring us closer to the day when photovoltaic devices may reach grid parity with traditional fossil fuels on the electrical energy market. This dissertation advances our understanding of light trapping by first modeling the effects of loss in planar dielectric waveguides. The mathematical framework developed here can be used to model any arbitrary three-layer structure with mixed gain or loss and then extract the total field solution for the guided modes. It is found that lossy waveguides possess a greater number of eigenmodes than their lossless counterparts, and that these "loss guided" modes attenuate much more rapidly than conventional modes. Another contribution from this dissertation is the exploration of light trapping through the use of dielectric nanospheres embedded directly within the active layer of a thin silicon film. The primary benefit to this approach is that the device can utilize a surface nitride layer serving as an antireflective coating while still retaining the benefits of light trapping within the film. The end result is that light trapping and light injection are effectively decoupled from each other and may be independently optimized within a single photovoltaic device. The final contribution from this work is a direct numerical comparison between multiple light trapping schemes. This allows us to quantify the relative performances of various design techniques against one another and objectively determine which ideas tend to capture the most light. Using numerical simulation, this work directly compares the absorption

Maximization of permanent trapping of CO{sub 2} and co-contaminants in the highest-porosity formations of the Rock Springs Uplift (Southwest Wyoming): experimentation and multi-scale modeling

Energy Technology Data Exchange (ETDEWEB)

Piri, Mohammad

2014-03-31

Under this project, a multidisciplinary team of researchers at the University of Wyoming combined state-of-the-art experimental studies, numerical pore- and reservoir-scale modeling, and high performance computing to investigate trapping mechanisms relevant to geologic storage of mixed scCO{sub 2} in deep saline aquifers. The research included investigations in three fundamental areas: (i) the experimental determination of two-phase flow relative permeability functions, relative permeability hysteresis, and residual trapping under reservoir conditions for mixed scCO{sub 2}-­brine systems; (ii) improved understanding of permanent trapping mechanisms; (iii) scientifically correct, fine grid numerical simulations of CO{sub 2} storage in deep saline aquifers taking into account the underlying rock heterogeneity. The specific activities included: (1) Measurement of reservoir-­conditions drainage and imbibition relative permeabilities, irreducible brine and residual mixed scCO{sub 2} saturations, and relative permeability scanning curves (hysteresis) in rock samples from RSU; (2) Characterization of wettability through measurements of contact angles and interfacial tensions under reservoir conditions; (3) Development of physically-­based dynamic core-­scale pore network model; (4) Development of new, improved high-­performance modules for the UW-­team simulator to provide new capabilities to the existing model to include hysteresis in the relative permeability functions, geomechanical deformation and an equilibrium calculation (Both pore-­ and core-­scale models were rigorously validated against well-­characterized core-­ flooding experiments); and (5) An analysis of long term permanent trapping of mixed scCO{sub 2} through high-­resolution numerical experiments and analytical solutions. The analysis takes into account formation heterogeneity, capillary trapping, and relative permeability hysteresis.

Factors influencing pheromone trap effectiveness in attracting the banana weevil, Cosmopolites sordidus

NARCIS (Netherlands)

Tinzaara, W.; Gold, C.S.; Dicke, M.; Huis, van A.; Ragama, P.E.

2005-01-01

Studies were conducted in Uganda to evaluate the influence of distance, environmental factors, trap location and trap type on catches of Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) in pheromone-baited traps. Marked weevils were released at recorded locations within plots. Trap

Paths to light trapping in thin film GaAs solar cells.

Science.gov (United States)

Xiao, Jianling; Fang, Hanlin; Su, Rongbin; Li, Kezheng; Song, Jindong; Krauss, Thomas F; Li, Juntao; Martins, Emiliano R

2018-03-19

It is now well established that light trapping is an essential element of thin film solar cell design. Numerous light trapping geometries have already been applied to thin film cells, especially to silicon-based devices. Less attention has been paid to light trapping in GaAs thin film cells, mainly because light trapping is considered less attractive due to the material's direct bandgap and the fact that GaAs suffers from strong surface recombination, which particularly affects etched nanostructures. Here, we study light trapping structures that are implemented in a high-bandgap material on the back of the GaAs active layer, thereby not perturbing the integrity of the GaAs active layer. We study photonic crystal and quasi-random nanostructures both by simulation and by experiment and find that the photonic crystal structures are superior because they exhibit fewer but stronger resonances that are better matched to the narrow wavelength range where GaAs benefits from light trapping. In fact, we show that a 1500 nm thick cell with photonic crystals achieves the same short circuit current as an unpatterned 4000 nm thick cell. These findings are significant because they afford a sizeable reduction in active layer thickness, and therefore a reduction in expensive epitaxial growth time and cost, yet without compromising performance.

Arthropod diversity and abundance along the Kihansi Gorge ...

African Journals Online (AJOL)

Arthropod diversity and abundance at the order level was investigated along the Kihansi Gorge in the southern Udzungwa Mountains between June and August 1997 by using sweep netting, timed Lepidoptera counts, malaise-traps, solar powered light-¬traps, baited pitfall-traps, sticky-traps and baited butterfly traps.

Ultrasonic trap for light scattering measurement

Science.gov (United States)

Barton, Petr; Pavlu, Jiri

2017-04-01

Light scattering is complex phenomenon occurring widely in space environments, including the dense dusty clouds, nebulas or even the upper atmosphere of the Earth. However, when the size of the dust (or of other scattering center) is close to the incident light wavelength, theoretical determination is difficult. In such case, Mie theory is to be used but there is a lack of the material constants for most space-related materials. For experimental measurement of light scattering, we designed unique apparatus, based on ultrasonic trap. Using acoustic levitation we are able to capture the dust grain in midair, irradiate it with laser, and observe scattering directly with goniometer-mounted photodiode. Advantage of this approach is ability to measure directly in the air (thus, no need for the carrier medium) and possibility to study non-spherical particles. Since the trap development is nearly finished and initial experiments are carried out, the paper presents first tests on water droplets.

Efficiency of subaquatic light traps

Czech Academy of Sciences Publication Activity Database

Ditrich, Tomáš; Čihák, P.

2017-01-01

Roč. 38, č. 3 (2017), s. 171-184 ISSN 0165-0424 R&D Projects: GA ČR(CZ) GA14-29857S Institutional support: RVO:60077344 Keywords : Heteroptera * Diptera * light trap Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 0.524, year: 2016

A detailed study of CO₂-brine capillary trapping mechanisms as applied to geologic carbon storage. Final Report

Energy Technology Data Exchange (ETDEWEB)

Wildenschild, Dorthe [Oregon State Univ., Corvallis, OR (United States)

2017-04-06

The proposed research focuses on improved fundamental understanding of the efficiency of physical trapping mechanisms, and as such will provide the basis for subsequent upscaling efforts. The overarching hypothesis of the proposed research is that capillary pressure plays a significant role in capillary trapping of CO₂, especially during the water imbibition stage of the sequestration process. We posit that the relevant physics of the sequestration process is more complex than is currently captured in relative permeability models, which are often based on so-called trapping models to represent relative permeability hysteresis. Our 4 main questions, guiding the 4 main tasks of the proposed research, are as follows: (1) What is the morphology of capillary trapped CO₂ at the pore scale as a function of temperature, pressure, brine concentration, interfacial tension, and pore-space morphology under injection and subsequent imbibition? (2) Is it possible to describe the capillary trapping process using formation-dependent, but otherwise unique continuum-scale functions in permeability-capillary pressure, interfacial area and saturation space, rather than hysteretic functions in permeability-saturation or capillary pressure-saturation space? (3) How do continuum-scale relationships between kr-Pc-S-Anw developed based on pore-scale observations compare with traditional models incorporating relative permeability hysteresis (such as Land’s and other models,) and with observations at the core (5-10cm) scale? (4) How can trapped CO₂ volume be optimized via engineered injection and sweep strategies, and as a function of formation type (incl. heterogeneity)?

CO2 emissions from Super-light Structures

DEFF Research Database (Denmark)

Hertz, Kristian Dahl; Bagger, Anne

2011-01-01

CO2 emission from the construction of buildings is seldom taken into account because focus is primarily on building operation. New technologies have therefore mainly been developed to reduce the energy consumption connected to operation. Super-light technology is a new structural principle giving...

Nanophotonic light-trapping theory for solar cells

Energy Technology Data Exchange (ETDEWEB)

Yu, Zongfu; Raman, Aaswath; Fan, Shanhui [Stanford University, Ginzton Lab, Stanford, CA (United States)

2011-11-15

Conventional light-trapping theory, based on a ray-optics approach, was developed for standard thick photovoltaic cells. The classical theory established an upper limit for possible absorption enhancement in this context and provided a design strategy for reaching this limit. This theory has become the foundation for light management in bulk silicon PV cells, and has had enormous influence on the optical design of solar cells in general. This theory, however, is not applicable in the nanophotonic regime. Here we develop a statistical temporal coupled-mode theory of light trapping based on a rigorous electromagnetic approach. Our theory reveals that the standard limit can be substantially surpassed when optical modes in the active layer are confined to deep-subwavelength scale, opening new avenues for highly efficient next-generation solar cells. (orig.)

An aerial baiting system for the distribution of attenuated or recombinant rabies vaccines for foxes, raccoons, and skunks.

Science.gov (United States)

Johnston, D H; Voigt, D R; MacInnes, C D; Bachmann, P; Lawson, K F; Rupprecht, C E

1988-01-01

An aerial baiting system was developed to deliver oral rabies vaccines to wild carnivore vectors of rabies, e.g., red fox, striped skunk, and raccoon. The bait consists of a polyethylene bag that contains either a 30-g hamburger ball or a 25-mL cube of polyurethane sponge coated with a wax-beef tallow mixture containing 100-150 mg of tetracycline as a biomarker. Attractants used with the sponge were added to the bag (e.g., liver slurry, cheeses, fish oils, or fruits). Baits (greater than 80,000) were dropped from light aircraft at densities of 18-120 baits/km2 over test areas in Ontario and Pennsylvania. Rates of bait acceptance were assessed by the presence of fluorescent tetracycline deposits in the teeth of animals obtained from hunters and trappers. Bait acceptance reached 74% in foxes, 54% in skunks, 43% in raccoons, and 85% in coyotes in the Ontario trials; bait acceptance by raccoons in a small trial in Pennsylvania reached 76%. Also, 66% of juvenile foxes that ate baits ate a second bait 7 or more days after eating the first, thus giving the potential for a booster effect. The cost of aerial distribution of bait (excluding cost of bait and vaccine) in Canadian dollars was $1.45/km2. The aerial distribution system is capable of economically reaching a high proportion of foxes, skunks, and raccoons over large areas. Trials with attenuated ERA (Evelyn-Rokitnicki-Abelseth) vaccines are under way in Ontario.

Capillary pressure - saturation relations for supercritical CO2 and brine: Implications for capillary/residual trapping in carbonate reservoirs during geologic carbon sequestration

Science.gov (United States)

Wang, S.; Tokunaga, T. K.

2014-12-01

In geologic carbon sequestration (GCS), data on capillary pressure (Pc) - saturation (Sw) relations are routinely needed to appraise reservoir processes. Capillarity and its hysteresis have been often experimentally studied in oil-water, gas-water and three phase gas-oil-water systems, but fewer works have been reported on scCO2-water under in-situ reservoir conditions. Here, Pc-Sw relations of supercritical (sc) CO2 displacing brine, and brine rewetting the porous medium to trap scCO2 were studied to understand CO2 transport and trapping behavior in carbonate reservoirs under representative reservoir conditions. High-quality drainage and imbibition (and associated capillary pressure hysteresis) curves were measured under elevated temperature and pressure (45 ºC, 8.5 and 12 MPa) for scCO2-brine as well as at room temperature and pressure (23 ºC, 0.1 MPa) for air-brine in unconsolidated limestone and dolomite sand columns using newly developed semi-automated multistep outflow-inflow porous plate apparatus. Drainage and imbibition curves for scCO2-brine deviated from the universal scaling curves for hydrophilic interactions (with greater deviation under higher pressure) and shifted to lower Pc than predicted based on interfacial tension (IFT) changes. Augmented scaling incorporating differences in IFT and contact angle improved the scaling results but the scaled curves still did not converge onto the universal curves. Equilibrium residual trapping of the nonwetting phase was determined at Pc =0 during imbibition. The capillary-trapped amounts of scCO2 were significantly larger than for air. It is concluded that the deviations from the universal capillary scaling curves are caused by scCO2-induced wettability alteration, given the fact that pore geometry remained constant and IFT is well constrained. In-situ wettability alteration by reactive scCO2 is of critical importance and must be accounted for to achieve reliable predictions of CO2 behavior in GCS reservoirs.

Enhanced photocatalytic degradation of dye under visible light on mesoporous microspheres by defects in manganese- and nitrogen-co-doped TiO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Feng, Lu; Jiang, Heng, E-mail: hjiang78@hotmail.com [Liaoning Shihua University, School of Chemistry and Materials Science (China); Zou, Mingming; Xiong, Fengqiang; Ganeshraja, Ayyakannu Sundaram; Pervaiz, Erum [Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics (China); Liu, Yinan; Zou, Shunying [Dalian Environmental Protection Laboratory (China); Yang, Minghui, E-mail: myang@dicp.ac.cn [Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics (China)

2016-09-15

Manganese- and nitrogen-co-doped mesoporous TiO{sub 2} microsphere photocatalysts are prepared by a simple sol–gel method with controllable sizes in the range of 400–500 nm and high surface area of 112 m{sup 2} g{sup −1}. Manganous acetate is the Mn source, and ammonia gas is the nitrogen source used. The dopants are found to be uniformly distributed in the TiO{sub 2} matrix. Interestingly, in (Mn,N)-co-doped TiO{sub 2}, we observe an effective indirect band gap of ~2.58 eV. (Mn,N)-co-doped mesoporous TiO{sub 2} microspheres show higher photocatalytic activity than Mn–TiO{sub 2} microspheres under visible light irradiation. Among the samples reported in this work, 0.2 at.% Mn doping and 500 °C 2-h nitriding condition give the highest photocatalytic activity. The observed photocatalytic activity in the (Mn,N)-co-doped TiO{sub 2} is attributed to the contribution from improved absorption due to trap levels of Mn, oxygen vacancies and N doping.Graphical AbstractManganese- and nitrogen-co-doped mesoporous TiO{sub 2} microspheres containing substitutional N, interstitial N and O vacancies show high visible light photocatalytic activity.

Performance evaluation of locally developed black light trap for maize insects monitoring in Chitwan, Nepal

Directory of Open Access Journals (Sweden)

Ghanashyam Bhandari

2017-12-01

Full Text Available Till today, the light traps in Nepal are found using with traditional type, which have not being recognized internationally. These light traps were of low efficiency for trapping insects as compared to black light trap (BLT. The black light tube (F10T8/BL was used in newly constructed trap at National Maize Research Program (NMRP, Rampur, Chitwan, Nepal. Both traps were installed at the maize experimental field at NMRP during February to October, 2017. Data on insect numbers were recorded once in a week from dusk to down in two different days to minimize the light effects of each others. The total number of insects trapped in BLT was 2804 as compared to 868 in traditional light trap (TLT. Among the insect orders, Coleopterans were mostly trapped in BLT followed by Lepidopteron and Hemipterans. The results showed that the trapping efficiency of BLT was three fold higher than that of TLT. Therefore, black light trap was highly effective monitoring tool and its field applications are expected to be commercialized.

Light-Triggered CO2 Breathing Foam via Nonsurfactant High Internal Phase Emulsion.

Science.gov (United States)

Zhang, Shiming; Wang, Dingguan; Pan, Qianhao; Gui, Qinyuan; Liao, Shenglong; Wang, Yapei

2017-10-04

Solid materials for CO 2 capture and storage have attracted enormous attention for gaseous separation, environmental protection, and climate governance. However, their preparation and recovery meet the problems of high energy and financial cost. Herein, a controllable CO 2 capture and storage process is accomplished in an emulsion-templated polymer foam, in which CO 2 is breathed-in under dark and breathed-out under light illumination. Such a process is likely to become a relay of natural CO 2 capture by plants that on the contrary breathe out CO 2 at night. Recyclable CO 2 capture at room temperature and release under light irradiation guarantee its convenient and cost-effective regeneration in industry. Furthermore, CO 2 mixed with CH 4 is successfully separated through this reversible breathing in and out system, which offers great promise for CO 2 enrichment and practical methane purification.

Evaluation of Efficiency of Schoenly Trap for Collecting Adult Sarcosaprophagous Dipterans

DEFF Research Database (Denmark)

Ordonez Gloria, Alejandro

2008-01-01

Communities of adult sarcosaprophagous dipterans were evaluated using both Schoenly traps (BST) baited with rabbit carcasses and the traditional forensic methodology (TradC) in the Sabana de Bogota ́ , Colombia. During 42 sampling days, 2,726 adult dipterans were collected (2,291 by BST and 435...

Evaluation of efficiency of Schoenly trap for collecting adult sarcosaprophagous dipterans

NARCIS (Netherlands)

Ordonez, A.; Garcia, M. D.; Fagua, G.

Communities of adult sarcosaprophagous dipterans were evaluated using both Schoenly traps (BST) baited with rabbit carcasses and the traditional forensic methodology (TradC) in the Sabana de Bogota, Colombia. During 42 sampling days, 2,726 adult dipterans were collected (2,291 by BST and 435 by

Managing oriental fruit fly (Diptera: Tephritidae), with spinosad-based protein bait sprays and sanitation in papaya orchards in Hawaii.

Science.gov (United States)

Piñero, Jaime C; Mau, Ronald F L; Vargas, Roger I

2009-06-01

The efficacy of GF-120 NF Naturalyte Fruit Fly Bait in combination with field sanitation was assessed as a control for female oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), in papaya (Carica papaya L.) orchards in Hawaii. Three different bait spray regimes were evaluated: every row (high use of the bait), every fifth row (moderate use), and every 10th row (low use). Orchard plots in which no bait was applied served as controls. For five of the seven biweekly periods that followed the first bait spray, trapping data revealed significantly fewer female B. dorsalis captured in plots subject to high and moderate bait use than in control plots. Differences in incidence of infestation among treatments were detected only by the third (12 wk after first spray) fruit sampling with significantly fewer infested one-fourth to one-half ripe papaya fruit in plots subject to high and moderate bait use than in control plots. Parasitism rates by Fopius arisanus (Sonan) (Hymenoptera: Braconidae) were not negatively affected by bait application. Results indicate that foliar applications of GF-120 NF Naturalyte Fruit Fly Bait either to all rows (every other tree), or to every fifth row (every tree) in combination with good sanitation can effectively reduce infestation by B. dorsalis in papaya orchards in Hawaii.

Ternary ZnO/AgI/Ag2CO3 nanocomposites: Novel visible-light-driven photocatalysts with excellent activity in degradation of different water pollutants

International Nuclear Information System (INIS)

Golzad-Nonakaran, Behrouz; Habibi-Yangjeh, Aziz

2016-01-01

ZnO/AgI/Ag 2 CO 3 nanocomposites with different Ag 2 CO 3 contents were fabricated by a facile ultrasonic-irradiation method. The resultant samples were fairly characterized using XRD, EDX, SEM, TEM, UV–vis DRS, FT-IR, and PL techniques to reveal their microstructure, purity, morphology, and spectroscopic properties. Photocatalytic activity of the prepared samples was investigated by photodegradation of four dye pollutants (rhodamine B, methyl orange, methylene blue, and fuchsine) under visible-light irradiation. The photocatalytic experiments in degradation of rhodamine B showed that the ternary ZnO/AgI/Ag 2 CO 3 (30%) nanocomposite has an enhanced activity nearly 19 and 14 times higher than those of the binary ZnO/Ag 2 CO 3 and ZnO/AgI photocatalysts, respectively. Based on the obtained results, the highly enhanced activity was attributed to generation of more electron-hole pairs under visible-light irradiation and separation of the photogenerated charge carriers due to formation of tandem n-n heterojunctions between counterparts of the nanocomposite. The active species trapping experiments were also examined and it was showed that superoxide ion radicals play a vital role in the photocatalytic degradation reaction. More importantly, the ternary photocatalyst demonstrated good photostability. - Highlights: • ZnO/AgI/Ag 2 CO 3 nanocomposites were fabricated by an ultrasonic-irradiation method. • The activity was investigated by photodegradation of four dyes under visible light. • ZnO/AgI/Ag 2 CO 3 (30%) nanocomposite has the best activity under visible light. • Activity is 19 and 14-folds higher than ZnO/Ag 2 CO 3 and ZnO/AgI in degradation of RhB.

Description of the IMR Standard Light Trap and the Vertical ...

African Journals Online (AJOL)

The construction of different versions of a cheap, robust, and easy to operate light trap for catching various aquatic organisms is shown. The trap can be used to > 300 m depth and meets a number of criteria. Small-scale vertical distribution of decapod larvae was investigated during trap trials. The traps (6-10) were set for 24 ...

Closed Paths of Light Trapped in a Closed Fermat Curve

Science.gov (United States)

Dana-Picard, Thierry; Naiman, Aaron

2002-01-01

Geometric constructions have previously been shown that can be interpreted as rays of light trapped either in polygons or in conics, by successive reflections. The same question, trapping light in closed Fermat curves, is addressed here. Numerical methods are used to study the behaviour of the reflection points of a triangle when the degree of the…

Performance evaluation of locally developed black light trap for maize insects monitoring in Chitwan, Nepal

OpenAIRE

Ghanashyam Bhandari; Shiva Kumar Jha; Yagya Prasad Giri; Hira Kaji Manandhar; Pramod Kumar Jha; Nabaraj Devkota; Praseed Thapa; Resham Bahadur Thapa

2017-01-01

Till today, the light traps in Nepal are found using with traditional type, which have not being recognized internationally. These light traps were of low efficiency for trapping insects as compared to black light trap (BLT). The black light tube (F10T8/BL) was used in newly constructed trap at National Maize Research Program (NMRP), Rampur, Chitwan, Nepal. Both traps were installed at the maize experimental field at NMRP during February to October, 2017. Data on insect numbers were recorded ...

Towards the development of an autocontamination trap system to manage populations of emerald ash borer (Coleoptera: Buprestidae) with the native entomopathogenic fungus, Beauveria bassiana.

Science.gov (United States)

Lyons, D Barry; Iavallée, Robert; Kyei-Poku, George; Van Frankenhuyzen, Kees; Johny, Shajahan; Guertin, Claude; Francese, Joseph A; Jones, Gene C; Blais, Martine

2012-12-01

Emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is an invasive species from Asia that was discovered in North America Canada, in 2002. Herein, we describe studies to develop an autocontamination trapping system to disseminate Beauveria bassiana to control beetle populations. The standard trap for emerald ash borer in Canada is a light green prism trap covered in an insect adhesive and baited with (Z)-3-hexenol. We compared of green multifunnel traps, green intercept panel traps (both with and without fluon coating) and green prism traps for capturing emerald ash borer in a green ash plantation. The coated green multifunnel traps captured significantly more males and more females than any other trap design. We examined the efficacy of two native B. bassiana isolates, INRS-CFL and L49-1AA. In a field experiment the INRS-CFL isolate attached to multifunnel traps in autocontamination chambers retained its pathogenicity to emerald ash borer adults for up to 43 d of outdoor exposure. Conidia germination of the INRS-CFL isolate was >69% after outdoor exposure in the traps for up to 57 d. The L49-1AA isolate was not pathogenic in simulated trap exposures and the germination rate was extremely low (<5.3%). Mean (+/- SEM) conidia loads on ash borer adults after being autocontaminated in the laboratory using pouches that had been exposed in traps out of doors for 29 d were 579,200 (+/- 86,181) and 2,400 (+/- 681) for the INRS-CFL and the LA9-1AA isolates, respectively. We also examined the fungal dissemination process under field conditions using the L49-1AA isolate in a green ash plantation. Beetles were lured to baited green multifunnel traps with attached autocontamination chambers. Beetles acquired fungal conidia from cultures growing on pouches in the chambers and were recaptured on Pestick-coated traps. In total, 2,532 beetles were captured of which 165 (6.5%) had fungal growth that resembled B. bassiana. Of these 25 beetles were positive for

Optical trapping using cascade conical refraction of light.

Science.gov (United States)

O'Dwyer, D P; Ballantine, K E; Phelan, C F; Lunney, J G; Donegan, J F

2012-09-10

Cascade conical refraction occurs when a beam of light travels through two or more biaxial crystals arranged in series. The output beam can be altered by varying the relative azimuthal orientation of the two biaxial crystals. For two identical crystals, in general the output beam comprises a ring beam with a spot at its centre. The relative intensities of the spot and ring can be controlled by varying the azimuthal angle between the refracted cones formed in each crystal. We have used this beam arrangement to trap one microsphere within the central spot and a second microsphere on the ring. Using linearly polarized light, we can rotate the microsphere on the ring with respect to the central sphere. Finally, using a half wave-plate between the two crystals, we can create a unique beam profile that has two intensity peaks on the ring, and thereby trap two microspheres on diametrically opposite points on the ring and rotate them around the central sphere. Such a versatile optical trap should find application in optical trapping setups.

Capture of Anastrepha species (Diptera: Tephritidae) with multilure traps and biolure attractants in Guatemala

International Nuclear Information System (INIS)

Martinez, A.J.; Salinas, E.J.; Rendon, P.

2007-01-01

Two trapping systems were compared in a study in Guatemala during the wet season, May through Dec 2001. Trap/lure combinations consisting of green or yellow-based plastic McPhail-like traps baited with a synthetic 2-component lure (putrescine and ammonium acetate) and 300 mL of propylene glycol antifreeze as a preservative were compared to the traditional glass McPhail baited with torula yeast/borax and 300 mL of water. Both systems captured several key Anastrepha species including Anastrepha ludens Loew, A. obliqua, Macquart, A. serpentina Weidemann, A. striata Schiner, A. distincta Greene, A. fraterculus Weidemann as well as Ceratitis capitata Weidemann. Additionally, 13 other Anastrepha spp. were captured with the synthetic lure. The plastic traps captured more key flies than the McPhail trap except for A. distincta where there were no significant differences between the yellow-based plastic trap and the McPhail trap and no significant differences between any trap and lure for trapping A. fraterculus. The synthetic lure lasted 10 weeks. The sex ratio was female-biased for almost all captured key species in both systems. Moreover, there were significant numbers of captured nontarget insects in all traps; however, the captured flies in those traps with the synthetic lure were not adversely affected by these insects. Propylene glycol-based antifreeze was a superior preservative when compared to borax/water. (author) [es

Doping effects of Co2+ ions on ZnO nanorods and their photocatalytic properties

International Nuclear Information System (INIS)

Qiu Xiaoqing; Li Guangshe; Sun Xuefei; Li Liping; Fu Xianzhi

2008-01-01

A series of Zn 1-x Co x O nanorods with dopant content ranging from x = 0.00 to 0.10 was prepared by a wet chemical method. All Zn 1-x Co x O samples were investigated by x-ray diffraction, transmission electron microscopy, energy-dispersion x-ray line mapping analysis, and UV-visible absorption spectroscopy. It was found that Co 2+ ions were homogeneously substituted for Zn 2+ ions in ZnO nanorods. Rhodamine B degradation was used as a probe reaction to evaluate the effect of Co 2+ doping on ZnO nanorods and photocatalytic performance under UV light and visible light irradiation. Co 2+ ions acted as the trapping or recombination centers for electrons and holes, leading to a reduction in photodegradation efficiency under UV light illumination. Alternatively, Co 2+ ions enhanced the optical absorption and produced the photoinduced carriers under visible illumination in terms of two charge transfer transitions involving Co 2+ ions. Consequently, Co 2+ ions substituted in the lattice of ZnO nanorods significantly improved the visible light photocatalytic activity

All-oxide Raman-active traps for light and matter: probing redox homeostasis model reactions in aqueous environment.

Science.gov (United States)

Alessandri, Ivano; Depero, L E

2014-04-09

Core-shell colloidal crystals can act as very efficient traps for light and analytes. Here it is shown that Raman-active probes can be achieved using SiO2-TiO2 core-shell beads. These systems are successfully tested in monitoring of glutathione redox cycle at physiological concentration in aqueous environment, without need of any interfering enhancers. These materials represent a promising alternative to conventional, metal-based SERS probes for investigating chemical and biochemical reactions under real working conditions. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sticky traps saturate with navel orangeworm in a non-linear fashion

Science.gov (United States)

In order to evaluate saturation thresholds as well as differences among wing-trap types, we used unmated female navel orangeworm (NOW) as sex pheromone baits in wing-traps that varied by color and glue/trapping surface. These results were compared to male capture in red delta and simple water cup tr...

Light trapping with plasmonic back contacts in thin-film silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Paetzold, Ulrich Wilhelm

2013-02-08

small potential for increasing the reflection at the back contact with dielectric interlayers of even lower refractive index, such as SiO{sub 2} and air, is demonstrated. The light-trapping effect of two types of plasmonic back contacts, which make use of large and efficiently scattering Ag nanostructures, is studied in thin-film silicon solar cell prototypes. The first type of plasmonic back contact applies non-ordered Ag nanostructures. The preparation, characterization and three-dimensional electromagnetic simulations of these back contacts with various distributions of non-ordered Ag nanostructures are presented. Measured reflectance spectra of the Ag back contacts with non-ordered nanostructures are correlated with reflectance spectra derived from three-dimensional electromagnetic simulations of isolated nanostructures on Ag back contacts. A microcrystalline silicon solar cell fabricated on one type of plasmonic Ag back contact with non-ordered Ag nanostructures shows a significantly enhanced plasmonic light trapping when compared with a flat solar cell. The second type of plasmonic back contact applies periodic arrangements of plasmonic Ag nanostructures in a square lattice at the surface of the Ag back contact. It is called a plasmonic reflection grating back contact. A particular advantage of this device is the control of the scattering angles via the diffraction orders of the grating while taking advantage of the efficient plasmon-induced light scattering at the Ag nanostructures. The plasmonic reflection grating back contacts are prepared with a nanoimprint process. The prototype microcrystalline silicon solar cells exhibit a very good light-trapping effect. Even in comparison with solar cells with a state-of-the-art random texture for light trapping, an enhanced light-trapping effect is demonstrated for a solar sell with a plasmonic reflection grating of optimized period. Based on electromagnetic simulations, the light-trapping effect is explained from the

Ultraviolet safety assessments of insect light traps

OpenAIRE

Sliney, David H.; Gilbert, David W.; Lyon, Terry

2016-01-01

ABSTRACT Near-ultraviolet (UV-A: 315?400?nm), ?black-light,? electric lamps were invented in 1935 and ultraviolet insect light traps (ILTs) were introduced for use in agriculture around that time. Today ILTs are used indoors in several industries and in food-service as well as in outdoor settings. With recent interest in photobiological lamp safety, safety standards are being developed to test for potentially hazardous ultraviolet emissions. A variety of UV ?Black-light? ILTs were measured at...

Efficient light trapping in silicon inclined nanohole arrays for photovoltaic applications

Science.gov (United States)

Deng, Can; Tan, Xinyu; Jiang, Lihua; Tu, Yiteng; Ye, Mao; Yi, Yasha

2018-01-01

Structural design with high light absorption is the key challenge for thin film solar cells because of its poor absorption. In this paper, the light-trapping performance of silicon inclined nanohole arrays is systematically studied. The finite difference time domain method is used to calculate the optical absorption of different inclination angles in different periods and diameters. The results indicate that the inclined nanoholes with inclination angles between 5° and 45° demonstrate greater light-trapping ability than their counterparts of the vertical nanoholes, and they also show that by choosing the optimal parameters for the inclined nanoholes, a 31.2 mA/cm2 short circuit photocurrent density could be achieved, which is 10.25% higher than the best vertical nanohole system and 105.26% higher than bare silicon with a thickness of 2330 nm. The design principle proposed in this work gives a guideline for choosing reasonable parameters in the application of solar cells.

Assessing anti-rabies baiting – what happens on the ground?

Directory of Open Access Journals (Sweden)

Wyszomirski Tomasz

2004-03-01

Full Text Available Abstract Background Rabies is one of the most hazardous zoonoses in the world. Oral mass vaccination has developed into the most effective management method to control fox rabies. The future need to control the disease in large countries (i.e. Eastern Europe and the Americas forces cost-benefit discussions. The 'Increase bait density' option refers to the usual management assumption that more baits per km2 could compensate for high fox abundance and override the imperfect supply of bait pieces to the individual fox. Methods We use a spatial simulation, which combines explicitly fox space use (tessellation polygons and aeroplane flight lines (straight lines. The number of baits actually falling into each polygon is measured. The manager's strategic options are converted into changes of the resulting bait distribution on the ground. The comparison enables the rating of the options with respect to the management aim (i.e. accessibility of baits. Results Above 5% (approx. 10% of all fox groups without any bait (at most 5 baits relate to the baiting strategy applied in the field (1 km spaced parallel flight lines, 20 baits per km2 distributed under habitat conditions comparable to middle and western Europe (fox group home-range 1 km2, 2.5 adults; reference strategy. Increasing the bait density on the same flight-line pattern neither reduces the number of under-baited fox group home-ranges, nor improves the management outcome and hence wastes resources. However, reducing the flight line distance provides a more even bait distribution and thus compensates for missed fox groups or extra high fox density. The reference strategy's bait density can be reduced when accounting for the missed fox groups. The management result with the proper strategy is likely the same but with reduced costs. Conclusion There is no overall optimal strategy for the bait distribution in large areas. For major parts of the landscape, the reference strategy will be more

Evaluating the efficacy of a landscape scale feral cat control program using camera traps and occupancy models.

Science.gov (United States)

Comer, Sarah; Speldewinde, Peter; Tiller, Cameron; Clausen, Lucy; Pinder, Jeff; Cowen, Saul; Algar, Dave

2018-03-28

The impact of introduced predators is a major factor limiting survivorship and recruitment of many native Australian species. In particular, the feral cat and red fox have been implicated in range reductions and population declines of many conservation dependent species across Australia, including ground-nesting birds and small to medium-sized mammals. The impact of predation by feral cats since their introduction some 200 years ago has altered the structure of native fauna communities and led to the development of landscape-scale threat abatement via baiting programs with the feral cat bait, Eradicat. Demonstrating the effectiveness of broad-scale programs is essential for managers to fine tune delivery and timing of baiting. Efficacy of feral cat baiting at the Fortescue Marsh in the Pilbara, Western Australia was tested using camera traps and occupancy models. There was a significant decrease in probability of site occupancy in baited sites in each of the five years of this study, demonstrating both the effectiveness of aerial baiting for landscape-scale removal of feral cats, and the validity of camera trap monitoring techniques for detecting changes in feral cat occupancy during a five-year baiting program.

Visible-light Homogeneous Photocatalytic Conversion of CO2 into CO in Aqueous Solutions with an Iron Catalyst.

Science.gov (United States)

Rao, Heng; Bonin, Julien; Robert, Marc

2017-11-23

An iron-substituted tetraphenyl porphyrin bearing positively charged trimethylammonio groups at the para position of each phenyl ring catalyzes the photoinduced conversion of CO 2 . This complex is water soluble and acts as a molecular catalyst to selectively reduce CO 2 into CO under visible-light irradiation in aqueous solutions (acetonitrile/water=1:9 v/v) with the assistance of purpurin, a simple organic photosensitizer. CO is produced with a catalytic selectivity of 95 % and turnover number up to 120, illustrating the possibility of photocatalyzing the reduction of CO 2 in aqueous solution by using visible light, a simple organic sensitizer coupled to an amine as a sacrificial electron donor, and an earth-abundant metal-based molecular catalyst. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

PmaCO2 Project: Porosity and CO2 Trapping Mechanisms The Utrillas Formation in SD-1 borehole (Tejada - Burgos): Porosity and Porous Media Modelling

International Nuclear Information System (INIS)

Campos, R.; Barrios, I.; Gonzalez, A. M.

2013-02-01

The aim of PmaCO 2 project, supported by the Secretary of State and Research MINECO (CGL2011-24768) is to increase the knowledge of the microstructure of porous storage formations and thus contribute to the viability of CO 2 sequestration in geological formations. The microporous structure plays an important role not only in the prevalence of a particular trapping mechanism, but also on the amount of CO 2 immobilized. Utrillas facies are investigated in this project as representatives of a deep saline aquifer storage. This publication is a summary of the work done in the first year of the project. We present a study on microstructure of sandstones Utrillas, sampled in borehole, by applying the mercury intrusion porosimetry technique for the experimental determination of porosity and associated parameters. The porous medium was modeled with the PoreCor simulation code based in intrusion-extrusion curves. (Author) 78 refs.

Dislocation-related trap levels in nitride-based light emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Venturi, Giulia; Castaldini, Antonio; Cavallini, Anna [Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, Bologna 40127 (Italy); Meneghini, Matteo; Zanoni, Enrico [Department of Information Engineering, University of Padova, via Gradenigo 6/B, Padova 35131 (Italy); Zhu, Dandan; Humphreys, Colin [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

2014-05-26

Deep level transient spectroscopy was performed on InGaN/GaN multiple quantum well light emitting diodes (LEDs) in order to determine the effect of the dislocation density on the deep intragap electronic levels. The LEDs were grown by metalorganic vapor phase epitaxy on GaN templates with a high dislocation density of 8 × 10{sup 9} cm{sup −2} and a low dislocation density of 3 × 10{sup 8} cm{sup −2}. Three trapping levels for electrons were revealed, named A, A1, and B, with energies E{sub A} ≈ 0.04 eV, E{sub A1} ≈ 0.13 eV, and E{sub B} ≈ 0.54 eV, respectively. The trapping level A has a much higher concentration in the LEDs grown on the template with a high density of dislocations. The logarithmic dependence of the peak amplitude on the bias pulse width for traps A and A1 identifies the defects responsible for these traps as associated with linearly arranged defects. We conclude that traps A and A1 are dislocation-related intragap energy levels.

Dislocation-related trap levels in nitride-based light emitting diodes

International Nuclear Information System (INIS)

Venturi, Giulia; Castaldini, Antonio; Cavallini, Anna; Meneghini, Matteo; Zanoni, Enrico; Zhu, Dandan; Humphreys, Colin

2014-01-01

Deep level transient spectroscopy was performed on InGaN/GaN multiple quantum well light emitting diodes (LEDs) in order to determine the effect of the dislocation density on the deep intragap electronic levels. The LEDs were grown by metalorganic vapor phase epitaxy on GaN templates with a high dislocation density of 8 × 10 9 cm −2 and a low dislocation density of 3 × 10 8 cm −2 . Three trapping levels for electrons were revealed, named A, A1, and B, with energies E A  ≈ 0.04 eV, E A1  ≈ 0.13 eV, and E B  ≈ 0.54 eV, respectively. The trapping level A has a much higher concentration in the LEDs grown on the template with a high density of dislocations. The logarithmic dependence of the peak amplitude on the bias pulse width for traps A and A1 identifies the defects responsible for these traps as associated with linearly arranged defects. We conclude that traps A and A1 are dislocation-related intragap energy levels.

Development of odour-baited flytraps for sampling the African latrine fly, Chrysomya putoria, a putative vector of enteric diseases.

Directory of Open Access Journals (Sweden)

Thomas C Lindsay

Full Text Available African pit latrines produce prodigious numbers of the latrine fly, Chrysomya putoria, a putative vector of diarrhoeal pathogens. We set out to develop a simple, low-cost odour-baited trap for collecting C. putoria in the field. A series of field experiments was carried out in The Gambia to assess the catching-efficiency of different trap designs. The basic trap was a transparent 3L polypropylene box baited with 50 g of fish, with a white opaque lid with circular entrance holes. We tested variations of the number, diameter, position and shape of the entrance holes, the height of the trap above ground, degree of transparency of the box, its shape, volume, colour, and the attractiveness of gridded surfaces on or under the trap. Traps were rotated between positions on different sampling occasions using a Latin Square design. The optimal trapping features were incorporated into a final trap that was tested against commercially available traps. Features of the trap that increased the number of flies caught included: larger entrance holes (compared with smaller ones, p<0.001, using conical collars inside the holes (compared with without collars, p = 0.01, entrance holes on the top of the trap (compared with the side or bottom, p<0.001, traps placed on the ground (compared with above ground, p<0.001, the box having transparent sides (compared with being opaque, p<0.001, and with no wire grids nearby (compared with those with grids, p = 0.03. This trap collected similar numbers of C. putoria to other common traps for blow flies. The optimum trap design was a transparent box, with a white plastic lid on top, perforated with 10 conical entrance holes, placed on the ground. Our simple trap provides a cheap, low-maintenance and effective method of sampling C. putoria in the field.

Fabrication of the replica templated from butterfly wing scales with complex light trapping structures

Science.gov (United States)

Han, Zhiwu; Li, Bo; Mu, Zhengzhi; Yang, Meng; Niu, Shichao; Zhang, Junqiu; Ren, Luquan

2015-11-01

The polydimethylsiloxane (PDMS) positive replica templated twice from the excellent light trapping surface of butterfly Trogonoptera brookiana wing scales was fabricated by a simple and promising route. The exact SiO2 negative replica was fabricated by using a synthesis method combining a sol-gel process and subsequent selective etching. Afterwards, a vacuum-aided process was introduced to make PDMS gel fill into the SiO2 negative replica, and the PDMS gel was solidified in an oven. Then, the SiO2 negative replica was used as secondary template and the structures in its surface was transcribed onto the surface of PDMS. At last, the PDMS positive replica was obtained. After comparing the PDMS positive replica and the original bio-template in terms of morphology, dimensions and reflectance spectra and so on, it is evident that the excellent light trapping structures of butterfly wing scales were inherited by the PDMS positive replica faithfully. This bio-inspired route could facilitate the preparation of complex light trapping nanostructure surfaces without any assistance from other power-wasting and expensive nanofabrication technologies.

Trapping Triatominae in Silvatic Habitats

Directory of Open Access Journals (Sweden)

Noireau François

2002-01-01

Full Text Available Large-scale trials of a trapping system designed to collect silvatic Triatominae are reported. Live-baited adhesive traps were tested in various ecosystems and different triatomine habitats (arboreal and terrestrial. The trials were always successful, with a rate of positive habitats generally over 20% and reaching 48.4% for palm trees of the Amazon basin. Eleven species of Triatominae belonging to the three genera of public health importance (Triatoma, Rhodnius and Panstrongylus were captured. This trapping system provides an effective way to detect the presence of triatomines in terrestrial and arboreal silvatic habitats and represents a promising tool for ecological studies. Various lines of research are contemplated to improve the performance of this trapping system.

Evaluation of the effectiveness of light streamer tori-lines and characteristics of bait attacks by seabirds in the western North Pacific.

Directory of Open Access Journals (Sweden)

Noriyosi Sato

Full Text Available To improve the effectiveness of tori-lines it is necessary to evaluate the ability of tori-lines to mitigate seabird bycatch and determine what kind of seabird species gather during line settings, attack the bait and are incidentally caught. We conducted two experiments in the western North Pacific and examined the effectiveness for seabird mitigation of light streamer tori-lines which have no long streamers but many light (short streamers and are mainly used in the North Pacific area. Firstly, the effectiveness of two different types of tori-line (light streamer (1 m and long streamer (up to 7 m tori-line and of two different colors (yellow and red of light streamers for seabird bycatch avoidance was evaluated using 567 sets based on data from 20 offshore surface commercial longliners. No significant difference in the bycatch number between the different tori-line types and streamer colors was found. Secondly, we investigated the characteristics of the seabird bycatch in the North Pacific and the effectiveness of three different types of streamers (light, hybrid and modified light types by detailed observations of seabird attacks using a chartered longline vessel. Although the appearance rate of albatrosses and shearwaters were 40.9% and 27.7%, Laysan albatross was the main seabird species that followed the vessel but shearwaters seldom followed the vessel and did not aggregate during line setting. In all attacks on bait observed during line settings, 81% and 7% were by albatrosses and shearwaters, respectively. In the number of primary attacks by Laysan albatrosses which attacked most aggressively of all seabirds, there were no significant differences among the tori-line types. No individuals of shearwater were caught. The results of both experiments indicated that light streamer tori-lines were as effective as tori-lines with long streamers for mitigating seabird bycatch in the North Pacific.

Efficient visible light photocatalytic NO{sub x} removal with cationic Ag clusters-grafted (BiO){sub 2}CO{sub 3} hierarchical superstructures

Energy Technology Data Exchange (ETDEWEB)

Feng, Xin [Chongqing Key Laboratory of Catalysis and Functional Organic Molecules, College of Environment and Resources, Engineering Research Center for Waste Oil Recovery Technology and Equipment of Ministry of Education, College of Environment and Resources, Chongqing Technology and Business University, Chongqing 40067 (China); Zhang, Wendong [Department of Scientific Research Management, Chongqing Normal University, Chongqing 401331 (China); Deng, Hua [State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Ni, Zilin [Department of Scientific Research Management, Chongqing Normal University, Chongqing 401331 (China); Dong, Fan, E-mail: dfctbu@126.com [Chongqing Key Laboratory of Catalysis and Functional Organic Molecules, College of Environment and Resources, Engineering Research Center for Waste Oil Recovery Technology and Equipment of Ministry of Education, College of Environment and Resources, Chongqing Technology and Business University, Chongqing 40067 (China); Zhang, Yuxin, E-mail: zhangyuxin@cqu.edu.cn [College of Materials Science and Engineering, National Key Laboratory of Fundamental Science of Micro/Nano-Devices and System Technology, Chongqing University, Chongqing 400044 (China)

2017-01-15

Graphical abstract: The cationic Ag clusters-grafted (BiO){sub 2}CO{sub 3} hierarchical superstructures exhibits highly enhanced visible light photocatalytic air purification through an interfacial charge transfer process induced by Ag clusters. - Highlights: • Microstructural optimization and surface cluster-grafting were firstly combined. • Cationic Ag clusters were grafted on the surface of (BiO){sub 2}CO{sub 3} superstructures. • The Ag clusters-grafted BHS displayed enhanced visible light photocatalysis. • Direct interfacial charge transfer (IFCT) from BHS to Ag clusters was proposed. • The charge transfer process and the dominant reactive species were revealed. - Abstract: A facile method was developed to graft cationic Ag clusters on (BiO){sub 2}CO{sub 3} hierarchical superstructures (BHS) surface to improve their visible light activity. Significantly, the resultant Ag clusters-grafted BHS displayed a highly enhanced visible light photocatalytic performance for NOx removal due to the direct interfacial charge transfer (IFCT) from BHS to Ag clusters. The chemical and coordination state of the cationic Ag clusters was determined with the extended X-ray absorption fine structure (EXAFS) and a theoretical structure model was proposed for this unique Ag clusters. The charge transfer process and the dominant reactive species (·OH) were revealed on the basis of electron spin resonance (ESR) trapping. A new photocatalysis mechanism of Ag clusters-grafted BHS under visible light involving IFCT process was uncovered. In addition, the cationic Ag clusters-grafted BHS also demonstrated high photochemical and structural stability under repeated photocatalysis runs. The perspective of enhancing photocatalysis through combination of microstructural optimization and IFCT could provide a new avenue for the developing efficient visible light photocatalysts.

Wide-angle light-trapping electrode for photovoltaic cells.

Science.gov (United States)

Omelyanovich, Mikhail M; Simovski, Constantin R

2017-10-01

In this Letter, we experimentally show that a submicron layer of a transparent conducting oxide that may serve a top electrode of a photovoltaic cell based on amorphous silicon when properly patterned by notches becomes an efficient light-trapping structure. This is so for amorphous silicon thin-film solar cells with properly chosen thicknesses of the active layers (p-i-n structure with optimal thicknesses of intrinsic and doped layers). The nanopatterned layer of transparent conducting oxide reduces both the light reflectance from the photovoltaic cell and transmittance through the photovoltaic layers for normal incidence and for all incidence angles. We explain the physical mechanism of our light-trapping effect, prove that this mechanism is realized in our structure, and show that the nanopatterning is achievable in a rather easy and affordable way that makes our method of solar cell enhancement attractive for industrial adaptations.

Time and financial costs of programs for live trapping feral cats.

Science.gov (United States)

Nutter, Felicia B; Stoskopf, Michael K; Levine, Jay F

2004-11-01

To determine the time and financial costs of programs for live trapping feral cats and determine whether allowing cats to become acclimated to the traps improved trapping effectiveness. Prospective cohort study. 107 feral cats in 9 colonies. 15 traps were set at each colony for 5 consecutive nights, and 5 traps were then set per night until trapping was complete. In 4 colonies, traps were immediately baited and set; in the remaining 5 colonies, traps were left open and cats were fed in the traps for 3 days prior to the initiation of trapping. Costs for bait and labor were calculated, and trapping effort and efficiency were assessed. Mean +/- SD overall trapping effort (ie, number of trap-nights until at least 90% of the cats in the colony had been captured or until no more than 1 cat remained untrapped) was 8.9 +/- 3.9 trap-nights per cat captured. Mean overall trapping efficiency (ie, percentage of cats captured per colony) was 98.0 +/- 4.0%. There were no significant differences in trapping effort or efficiency between colonies that were provided an acclimation period and colonies that were not. Overall trapping costs were significantly higher for colonies provided an acclimation period. Results suggest that these live-trapping protocols were effective. Feeding cats their regular diets in the traps for 3 days prior to the initiation of trapping did not have a significant effect on trapping effort or efficiency in the present study but was associated with significant increases in trapping costs.

Response ofMeteorus leviventris, (Hymenoptera: Braconidae) to mustard oils in field trapping experiments.

Science.gov (United States)

Pivnick, K A

1993-09-01

Trapping experiments were carried out near Saskatoon, Canada, from May through August 1990 to assess the response of the braconid wasp,Meteorus leviventris, to four selected mustard oils or isothiocyanates (IC) at a release rate of 4 mg/day, and for allyl IC only, at 40 mg/day. Only allyl IC at 4 mg/day was significantly attractive when trap captures were compared to the captures in the control traps. The others (n-propyl IC, 2-phenylethyl IC., and ethyl IC) were not attractive, nor was allyl IC at the higher dose, although trap captures with the latter bait were the second highest.

Standardization of Ceratitis capitata Wied. (Diptera: Tephritidae) female trapping for use in sterile insect programmes. Catamarca, Argentina, 1995-1997

International Nuclear Information System (INIS)

Vattuone, M.

1999-01-01

The main objective of the study was to assess Ceratitis capitata Wied. (medfly) female trapping with new traps and attractants in varying ecological conditions as part of a co-ordinated international programme. Trials were carried out between 1995 and 1997, using seven types of traps baited with the various combination of sexual and food attractants. Different methods for insects retention were also tested. For these trials, protocols established by the International Atomic Energy Agency were followed. The Jackson Trap with Trimedlure plugs proved to be the most efficient for capture of medfly males, while International Pheromone's McPhail Trap was the most efficient for the capture of females, when used with a combination of all three new attractants (FA-3) consisting of ammonium acetate, putrescine, and trimethylamine plus the toxicant DDVP for insect retention. The new traps and attractants also captured flies belonging to genus Anastrepha (Diptera: Tephritidae). (author)

Light-Duty Vehicle CO2 and Fuel Economy Trends

Science.gov (United States)

This report provides data on the fuel economy, carbon dioxide (CO2) emissions, and technology trends of new light-duty vehicles (cars, minivans, sport utility vehicles, and pickup trucks) for model years 1975 to present in the United States.

Light availability and temperature, not increased CO2, will structure future meadows of Posidonia oceanica

KAUST Repository

Hendriks, Iris E.; Olsen, Ylva S.; Duarte, Carlos M.

2017-01-01

We evaluated the photosynthetic performance of Posidonia oceanica during short-term laboratory exposures to ambient and elevated temperatures (24–25°C and 29–30°C) warming and pCO2 (380, 750 and 1000ppm pCO2) under normal and low light conditions (200 and 40μmol photons m−2s−1 respectively). Plant growth was measured at the low light regime and showed a negative response to warming. Light was a critical factor for photosynthetic performance, although we found no evidence of compensation of photosynthetic quantum efficiency in high light. Relative Electron Rate Transport (rETRmax) was higher in plants incubated in high light, but not affected by pCO2 or temperature. The saturation irradiance (Ik) was negatively affected by temperature. We conclude that elevated CO2 does not enhance photosynthetic activity and growth, in the short term for P. oceanica, while temperature has a direct negative effect on growth. Low light availability also negatively affected photosynthetic performance during the short experimental period examined here. Therefore increasing concentrations of CO2 may not compensate for predicted future conditions of warmer water and higher turbidity for seagrass meadows.

Light availability and temperature, not increased CO2, will structure future meadows of Posidonia oceanica

KAUST Repository

Hendriks, Iris E.

2017-02-15

We evaluated the photosynthetic performance of Posidonia oceanica during short-term laboratory exposures to ambient and elevated temperatures (24–25°C and 29–30°C) warming and pCO2 (380, 750 and 1000ppm pCO2) under normal and low light conditions (200 and 40μmol photons m−2s−1 respectively). Plant growth was measured at the low light regime and showed a negative response to warming. Light was a critical factor for photosynthetic performance, although we found no evidence of compensation of photosynthetic quantum efficiency in high light. Relative Electron Rate Transport (rETRmax) was higher in plants incubated in high light, but not affected by pCO2 or temperature. The saturation irradiance (Ik) was negatively affected by temperature. We conclude that elevated CO2 does not enhance photosynthetic activity and growth, in the short term for P. oceanica, while temperature has a direct negative effect on growth. Low light availability also negatively affected photosynthetic performance during the short experimental period examined here. Therefore increasing concentrations of CO2 may not compensate for predicted future conditions of warmer water and higher turbidity for seagrass meadows.

Photocatalytic oxidation removal of Hg{sup 0} using ternary Ag/AgI-Ag{sub 2}CO{sub 3} hybrids in wet scrubbing process under fluorescent light

Energy Technology Data Exchange (ETDEWEB)

Zhang, Anchao, E-mail: aczhang@qq.com [School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo, 454000 (China); Zhang, Lixiang; Chen, Xiaozhuan; Zhu, Qifeng; Liu, Zhichao [School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo, 454000 (China); Xiang, Jun, E-mail: xiangjun@mail.hust.edu.cn [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, 430074 (China)

2017-01-15

Highlights: • Ag/AgI-Ag{sub 2}CO{sub 3} hybrids were employed for Hg{sup 0} removal under fluorescent light. • Superoxide radical (·O{sub 2}{sup −}) played a key role in Hg{sup 0} removal. • NO exhibited a significant effect on Hg{sup 0} removal in comparison to SO{sub 2}. • The mechanism for enhanced Hg{sup 0} removal over Ag/AgI-Ag{sub 2}CO{sub 3} was proposed. - Abstract: A series of ternary Ag/AgI-Ag{sub 2}CO{sub 3} photocatalysts synthesized using a facile coprecipitation method were employed to investigate their performances of Hg{sup 0} removal in a wet scrubbing reactor. The hybrids were characterized by N{sub 2} adsorption-desorption, XRD, SEM-EDS, HRTEM, XPS, DRS and ESR. The photocatalytic activities of Hg{sup 0} removal were evaluated under fluorescent light. The results showed that AgI content, fluorescent light irradiation, reaction temperature all showed significant influences on Hg{sup 0} removal. NO exhibited significant effect on Hg{sup 0} removal in comparison to SO{sub 2}. Among these ternary Ag/AgI-Ag{sub 2}CO{sub 3} hybrids, Ag/AgI(0.1)-Ag{sub 2}CO{sub 3} showed the highest Hg{sup 0} removal efficiency, which could be ascribed to the effective separation of photogenerated electron-hole pairs between AgI and Ag{sub 2}CO{sub 3} and the surface plasmon resonance (SPR) effect in the visible region by metallic silver nanoparticles (Ag{sup 0} NPs). The trapping studies of reactive radicals showed that the superoxide radicals (·O{sub 2}{sup −}) may play a key role in Hg{sup 0} removal under fluorescent light. According to the experimental and characterization results, a possible photocatalytic oxidation mechanism for enhanced Hg{sup 0} removal over Ag/AgI(0.1)-Ag{sub 2}CO{sub 3} hybrid under fluorescent light was proposed.

Ternary ZnO/AgI/Ag{sub 2}CO{sub 3} nanocomposites: Novel visible-light-driven photocatalysts with excellent activity in degradation of different water pollutants

Energy Technology Data Exchange (ETDEWEB)

Golzad-Nonakaran, Behrouz; Habibi-Yangjeh, Aziz, E-mail: ahabibi@uma.ac.ir

2016-12-01

ZnO/AgI/Ag{sub 2}CO{sub 3} nanocomposites with different Ag{sub 2}CO{sub 3} contents were fabricated by a facile ultrasonic-irradiation method. The resultant samples were fairly characterized using XRD, EDX, SEM, TEM, UV–vis DRS, FT-IR, and PL techniques to reveal their microstructure, purity, morphology, and spectroscopic properties. Photocatalytic activity of the prepared samples was investigated by photodegradation of four dye pollutants (rhodamine B, methyl orange, methylene blue, and fuchsine) under visible-light irradiation. The photocatalytic experiments in degradation of rhodamine B showed that the ternary ZnO/AgI/Ag{sub 2}CO{sub 3} (30%) nanocomposite has an enhanced activity nearly 19 and 14 times higher than those of the binary ZnO/Ag{sub 2}CO{sub 3} and ZnO/AgI photocatalysts, respectively. Based on the obtained results, the highly enhanced activity was attributed to generation of more electron-hole pairs under visible-light irradiation and separation of the photogenerated charge carriers due to formation of tandem n-n heterojunctions between counterparts of the nanocomposite. The active species trapping experiments were also examined and it was showed that superoxide ion radicals play a vital role in the photocatalytic degradation reaction. More importantly, the ternary photocatalyst demonstrated good photostability. - Highlights: • ZnO/AgI/Ag{sub 2}CO{sub 3} nanocomposites were fabricated by an ultrasonic-irradiation method. • The activity was investigated by photodegradation of four dyes under visible light. • ZnO/AgI/Ag{sub 2}CO{sub 3} (30%) nanocomposite has the best activity under visible light. • Activity is 19 and 14-folds higher than ZnO/Ag{sub 2}CO{sub 3} and ZnO/AgI in degradation of RhB.

Optical diagnostics of CO2 laser-fusion targets using backscattered light

International Nuclear Information System (INIS)

Casperson, D.E.

1981-01-01

With the f/2.4 focusing optics on one of the eight Helios CO 2 laser beam lines, direct backscattered light from a variety of glass microballoon targets has been observed. The quantities that have been measured include: (1) the total backscattered energy; (2) relative amplitudes of the backscattered fundamental and low harmonics (n = 1, 2, 3) of the 10.6 μm incident light; (3) the 3/2 harmonic emission from a double pulse backscatter experiment; (4) the temporally resolved 10.6 μm light using a fast pyroelectric detector and a Los Alamos 5-GHz oscilloscope; and (5) the time-integrated spectrally resolved fundamental using a 3/4 meter spectrometer and a high resolution pyroelectric detector array (resolution approx. 40 A at 10.6 μm). The suitability of these diagnostics for evaluating the CO 2 laser plasma in terms of stimulated scattering processes, plasma density gradients, velocity of the critical surface, etc., is discussed

Final report of “A Detailed Study of the Physical Mechanisms Controlling CO2-Brine Capillary Trapping in the Subsurface” (University of Arizona, DE-SC0006696)

Energy Technology Data Exchange (ETDEWEB)

Schaap, Marcel G. [Univ. of Arizona, Tucson, AZ (United States)

2016-07-25

Carbon capture and storage (CCS) of carbon dioxide emissions generated by production or combustion of fossil fuels is a technologically viable means to reduce the build-up of CO2 in the atmosphere and oceans. Using advantages of scale and location, CCS is particularly suitable for large point sources near ubiquitous deep saline aquifers, depleted gas reservoirs, or at production reservoirs for enhanced oil recovery (EOR). In the BES-funded research project, Oregon State University (OSU) carried out capillary trapping experiments with proxy fluids that mimic the properties of the scCO2/brine system under ambient temperatures and pressures, and successfully developed a unique and novel x-ray compatible, high-pressure, elevated temperature setup to study the scCO2/brine system under challenging reservoir conditions. Both methodologies were applied to a variety of porous media, including synthetic (glass bead) and geologic (Bentheimer sandstone) materials. The University of Arizona (UA) developed pore-scale lattice Boltzmann (LB) models which are able to handle the experimental conditions for proxy fluids, as well as the scCO2/brine system, that are capable of simulating permeability in volumes of tens of millions of fluid elements. We reached the following summary findings (main institute indicated): 1. (OSU/UA) To understand capillary trapping in a multiphase fluid-porous medium system, the system must be analyzed from a pore-scale force balance perspective; trapping can be enhanced by manipulating wetting and nonwetting phase fluid properties. 2. (OSU) Pore-scale fluid connectivity and topology has a clear and direct effect on nonwetting phase capillary trapping efficiency. 3. (OSU) Rock type and flow regime also have a pronounced effects on capillary trapping. 4. (OSU/UA) There is a predictable relationship between NWP connectivity and NWP saturation, which allows for development of injection strategies that optimize trapping. The commonly used Land model (Land

Trapping social wasps (Hymenoptera: Vespidae) with acetic acid and saturated short chain alcohols.

Science.gov (United States)

Landolt, P J; Smithhisler, C S; Reed, H C; McDonough, L M

2000-12-01

Nineteen compounds were evaluated in combination with a solution of acetic acid as baits for trapping the German yellowjacket, Vespula germanica (F.), the western yellowjacket Vespula pensylvanica (Sausssure), and the golden paper wasp Polistes aurifer Saussure. Compounds with three to six carbon chains or branched chains and with a hydroxy functional group were selected for testing based on their similarity to isobutanol. They were compared with isobutanol with acetic acid, which is a known wasp attractant. None of the compounds tested were superior to isobutanol when presented with acetic acid as a lure for these species of wasps. However, traps baited with either the S-(-)- or the racemic mixture of 2-methyl-1-butanol in combination with acetic acid captured similar numbers of both species of yellowjackets, compared with isobutanol with acetic acid. Polistes aurifer responded strongly to the S-(-)-enantiomer and to the racemic mixture of 2-methyl-1-butanol with acetic acid and not to the R-(+)-enantiomer with acetic acid.

Smart worm-like micelles responsive to CO2/N2 and light dual stimuli.

Science.gov (United States)

Jiang, Jianzhong; Wang, Guozheng; Ma, Yuxuan; Cui, Zhenggang; Binks, Bernard P

2017-04-12

CO 2 /N 2 and light dual stimuli-responsive worm-like micelles (WLMs) were obtained by addition of a relatively small amount of a switchable surfactant, 4-butyl-4'-(4-N,N-dimethylhexyloxy-amine) azobenzene bicarbonate (AZO-B6-CO 2 ), sensitive to the same triggers to a binary aqueous solution of cetyltrimethylammonium bromide (CTAB) and sodium salicylate (NaSal).

C60 as an Atom Trap to Capture Co Adatoms

DEFF Research Database (Denmark)

Yang, Peng; Li, Dongzhe; Repain, Vincent

2015-01-01

C60 molecules were used to trap Co adatoms and clusters on a Au(111) surface using atomic/molecular manipulation with a scanning tunneling microscope. Two manipulation pathways (successive integration of single Co atoms in one molecule or direct integration of a Co cluster) were found...... to efficiently allow the formation of complexes mixing a C60 molecule with Co atoms. Scanning tunneling spectroscopy reveals the robustness of the pi states of C60 that are preserved after Co trapping. Scanning tunneling microscopy images and density functional theory calculations reveal that dissociated Co...... clusters of up to nine atoms can be formed at the molecule-substrate interface. These results open new perspectives in the interactions between metal adatoms and molecules, for applications in metal-organic devices...

Enhanced photocatalytic CO2 reduction to CH4 over separated dual co-catalysts Au and RuO2

Science.gov (United States)

Dong, Chunyang; Hu, Songchang; Xing, Mingyang; Zhang, Jinlong

2018-04-01

A spatially separated, dual co-catalyst photocatalytic system was constructed by the stepwise introduction of RuO2 and Au nanoparticles (NPs) at the internal and external surfaces of a three dimensional, hierarchically ordered TiO2-SiO2 (HTSO) framework (the final photocatalyst was denoted as Au/HRTSO). Characterization by HR-TEM, EDS-mapping, XRD and XPS confirmed the existence and spatially separated locations of Au and RuO2. In CO2 photocatalytic reduction (CO2PR), Au/HRTSO (0.8%) shows the optimal performance in both the activity and selectivity towards CH4; the CH4 yield is almost twice that of the singular Au/HTSO or HRTSO (0.8%, weight percentage of RuO2) counterparts. Generally, Au NPs at the external surface act as electron trapping agents and RuO2 NPs at the inner surface act as hole collectors. This advanced spatial configuration could promote charge separation and transfer efficiency, leading to enhanced CO2PR performance in both the yield and selectivity toward CH4 under simulated solar light irradiation.

A combined methodology using electrical resistivity tomography, ordinary kriging and porosimetry for quantifying total C trapped in carbonate formations associated with natural analogues for CO2 leakage

Science.gov (United States)

Prado-Pérez, A. J.; Aracil, E.; Pérez del Villar, L.

2014-06-01

Currently, carbon deep geological storage is one of the most accepted methods for CO2 sequestration, being the long-term behaviour assessment of these artificial systems absolutely essential to guarantee the safety of the CO2 storage. In this sense, hydrogeochemical modelling is being used for evaluating any artificial CO2 deep geological storage as a potential CO2 sinkhole and to assess the leakage processes that are usually associated with these engineered systems. Carbonate precipitation, as travertines or speleothems, is a common feature in the CO2 leakage scenarios and, therefore, is of the utmost importance to quantify the total C content trapped as a stable mineral phase in these carbonate formations. A methodology combining three classical techniques such as: electrical resistivity tomography, geostatistical analysis and mercury porosimetry is described in this work, which was developed for calculating the total amount of C trapped as CaCO3 associated with the CO2 leakages in Alicún de las Torres natural analogue (Granada, Spain). The proposed methodology has allowed estimating the amount of C trapped as calcite, as more than 1.7 Mt. This last parameter, focussed on an artificial CO2 deep geological storage, is essential for hydrogeochemical modellers when evaluating whether CO2 storages constitute or not CO2 sinkholes. This finding is extremely important when assessing the long-term behaviour and safety of any artificial CO2 deep geological storage.

Attraction of Tomicus yunnanensis (Coleoptera: Scolytidae to Yunnan Pine Logs with and without Periderm or Phloem: An Effective Monitoring Bait

Directory of Open Access Journals (Sweden)

Rong Chun Lu

2012-01-01

Full Text Available The Yunnan pine shoot beetle, Tomicus yunnanensis Kirkendall and Faccoli (Coleoptera: Scolytinae is an important pest of Yunnan pine (Pinus yunnanensis Franch in China. Experiments with host log baits were done to develop a pest monitoring system using host tree kairomone. Five Yunnan pine logs (each 10–15 cm diam. × 30-cm long in a trap-log bundle were treated by peeling periderm (outer bark off to expose the phloem, and half of each log was covered with sticky adhesive to capture any attracted adult beetles. Significantly, more beetles were attracted and caught on the periderm-peeled logs (ca 30 beetles/m2 log surface/day than on untreated control logs with adhesive (ca 2.5/m2/day. No significant differences were observed between catches on logs taken from lower or upper halves of Yunnan pines. T. yunnanensis flies mostly during the afternoon according to trap catches throughout the day. Attraction to the periderm-peeled logs decreased considerably when they were peeled further to remove the phloem, indicating phloem volatiles play a role in selection of the host by the beetle. The readily-available log baits appear useful for monitoring pine shoot beetle populations in integrated pest management programs.

Efficacy of female attractant trapping systems for medfly for use in suppression programmes

International Nuclear Information System (INIS)

Seewooruthun, S.I.; Permalloo, S.; Sookar, P.

1999-01-01

Several species of fruit flies cause serious losses to fleshy fruits in Mauritius. Due to fruit production being confined mainly to backyard gardens, traditional methods of control do not give satisfactory results. Full cover sprays with chemicals also pose potential environmental and health risks. Alternative control methods were developed and an area-wide control programme was conceived, using bait application to bring down fruit fly population, followed by intensive trapping of males, using pheromones, to keep the population at low levels. An effective attractant system for mass trapping of females integrated into the wide area programme would greatly enhance control. The use of synthetic food-based attractants for trapping Ceratitis capitata and other fruit fly species was investigated in two phases and compared with different trapping systems. In the Phase III experiments, a two component lure, ammonium acetate + putrescine (FA-2) and a three component lure, ammonium acetate + putrescine + trimethylamine (FA-3) were tested in different traps and compared with standard liquid protein-baited International Pheromone's McPhail Trap (IPMT). Frutect trap, Tephri-trap and Jackson trap with Trimedlure were also used. The medfly female catch with the FA-3 lure used in the Open Bottom Dry Trap outnumbered the catches in other traps. In Phase IV, the final year of the trial, the FA-3 lure was tested in wet and dry IPMT and Tephri traps. These were compared with IPMT containing NuLure + borax (NU+B) as standard and with locally developed traps. The FA-3 lure gave the highest catches of female medflies in the IPMT with water as retaining device followed by IPMT with DDVP, although catches were not significantly different from IPMT with NU+B. (author)

Atractividad de diferentes cebos sobre Trógidos (Coleoptera en el Bosque Autóctono "El Espinal", Río Cuarto (Córdoba, Argentina Attractivity of different Baits on Trogids (Coleoptera in the Autochthonous Forest "El Espinal", Río Cuarto (Córdoba, Argentina

Directory of Open Access Journals (Sweden)

Rodrigo S. Gómez

2005-07-01

Full Text Available Se efectuó un estudio para determinar la atractividad de cebos sobre las especies de Trogidae presentes en el Bosque Autóctono "El Espinal" en la ciudad de Río Cuarto (Córdoba, Argentina. Se usaron trampas de caída cebadas con carne de vacuno (3, carne de porcino (3, menudo de pollo (3, excremento humano (3, excremento de perro (3 y trampas testigo (sin cebo (3 sumando un total de 18. Se recolectaron cuatro especies de Trogidae: Omorgus suberosus (Fabricius, Polynoncus aeger (Guérin-Meneville, Polynoncus gemmingeri (Harold y Polynoncus pilularius (Germar, que mostraron una preferencia hacia los menudos en descomposición de pollo y carne de cerdo seguido por excremento de perro; sugiriendo un comportamiento necrofágico-coprofágico con una tendencia a la necrofagia. Adicionalmente se utilizaron trampas de luz capturándose ejemplares de Omorgus ciliatus (Blanchard.A study to determine the food attractivity of baits on the species of Trogidae present in the Autochthonous Forest El Espinal in Río Cuarto City (Córdoba, Argentina was performed. Pitfall traps baited with beef (3, pork (3, chicken giblets (3, human excrement (3, dog excrement (3 and witness traps (without bait (3 were used, making up a total of 18 traps. Four species of Trogidae were collected Omorgus suberosus (Fabricius, Polynoncus aeger (Guérin-Meneville, Polynoncus gemmingeri (Harold and Polynoncus pilularius (Germar, which showed a preference for decomposing meat, especially chicken and pork, followed by dog excrement. Thus suggesting a necrophagous-coprophagous behavior with a tendency to the necrophagy. In an additional sampling light traps were used; Omorgus ciliatus (Blanchard was collected in these.

A sea lamprey (Petromyzon marinus) sex pheromone mixture increases trap catch relative to a single synthesized component in specific environments

Science.gov (United States)

Johnson, Nicholas S.; Tix, John A.; Hlina, Benjamin L.; Wagner, C. Michael; Siefkes, Michael J.; Wang, Huiyong; Li, Weiming

2015-01-01

Spermiating male sea lamprey (Petromyzon marinus) release a sex pheromone, of which a component, 7α, 12α, 24-trihydoxy-3-one-5α-cholan-24-sulfate (3kPZS), has been identified and shown to induce long distance preference responses in ovulated females. However, other pheromone components exist, and when 3kPZS alone was used to control invasive sea lamprey populations in the Laurentian Great Lakes, trap catch increase was significant, but gains were generally marginal. We hypothesized that free-ranging sea lamprey populations discriminate between a partial and complete pheromone while migrating to spawning grounds and searching for mates at spawning grounds. As a means to test our hypothesis, and to test two possible uses of sex pheromones for sea lamprey control, we asked whether the full sex pheromone mixture released by males (spermiating male washings; SMW) is more effective than 3kPZS in capturing animals in traditional traps (1) en route to spawning grounds and (2) at spawning grounds. At locations where traps target sea lampreys en route to spawning grounds, SMW-baited traps captured significantly more sea lampreys than paired 3kPZS-baited traps (~10 % increase). At spawning grounds, no difference in trap catch was observed between 3kPZS and SMW-baited traps. The lack of an observed difference at spawning grounds may be attributed to increased pheromone competition and possible involvement of other sensory modalities to locate mates. Because fishes often rely on multiple and sometimes redundant sensory modalities for critical life history events, the addition of sex pheromones to traditionally used traps is not likely to work in all circumstances. In the case of the sea lamprey, sex pheromone application may increase catch when applied to specifically designed traps deployed in streams with low adult density and limited spawning habitat.

RNA-Seq reveals the molecular mechanism of trapping and killing of root-knot nematodes by nematode-trapping fungi.

Science.gov (United States)

Pandit, Ramesh; Patel, Reena; Patel, Namrata; Bhatt, Vaibhav; Joshi, Chaitanya; Singh, Pawan Kumar; Kunjadia, Anju

2017-04-01

Nematode-trapping fungi are well known for their inherent potential to trap and kill nematodes using specialized trapping devices. However, the molecular mechanisms underlying the trapping and subsequent processes are still unclear. Therefore, in this study, we examined differential genes expression in two nematode-trapping fungi after baiting with nematode extracts. In Arthrobotrys conoides, 809 transcripts associated with diverse functions such as signal transduction, morphogenesis, stress response and peroxisomal proteins, proteases, chitinases and genes involved in the host-pathogen interaction showed differential expression with fold change (>±1.5 fold) in the presence of nematode extract with FDR (p-value nematode-trapping fungi for its host. The findings illustrate the molecular mechanism of fungal parasitism in A. conoides which may be helpful in developing a potential biocontrol agent against parasitic nematodes.

Light effect in photoionization of traps in GaN MESFETs

Directory of Open Access Journals (Sweden)

H. Arabshahi

2009-09-01

Full Text Available Trapping of hot electron behavior by trap centers located in buffer layer of a wurtzite phase GaN MESFET has been simulated using an ensemble Monte Carlo simulation. The results of the simulation show that the trap centers are responsible for current collapse in GaN MESFET at low temperatures. These electrical traps degrade the performance of the device at low temperature. On the opposite, a light-induced increase in the trap-limited drain current, results from the photoionization of trapped carriers and their return to the channel under the influence of the built in electric field associated with the trapped charge distribution. The simulated device geometries and doping are matched to the nominal parameters described for the experimental structures as closely as possible, and the predicted drain current and other electrical characteristics for the simulated device including trapping center effects show close agreement with the available experimental data.

Suppression of Mediterranean fruit fly populations over mountainous areas through aerial phloxine B - protein bait sprays: Regional Medfly programme in Guatemala

International Nuclear Information System (INIS)

McQuate, Grant T.; Peck, Steven L.

2000-01-01

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), was discovered in southern Mexico sometime in 1977 near Tapachula, Mexico. Farmers in Texas and other states of the United States became concerned that the Mediterranean fruit fly would spread northward through Mexico and into the US. In response to this threat to US agriculture, funds were appropriated by Congress to be used by the US Department of Agriculture (USDA) - Animal and Plant Health Inspection Service (APHIS) to eradicate the Mediterranean fruit flies from Mexico and establish a barrier zone in Guatemala to keep the Mediterranean fruit flies from spreading northward into Mexico. In Mexico and Guatemala, the organisation called MOSCAMED was created to support the programme. Aerially applied malathion bait sprays were used in the suppression programme beginning in Mexico in 1982 and beginning in Guatemala in 1985. Mexico has been free of the Mediterranean fruit fly since 1982, except for outbreaks in the southernmost state of Chiapas, adjacent to Guatemala. The spraying of malathion was banned by the government of Guatemala in early 1996 because of concern regarding possible adverse effects on honey bees. By this time, research had been started to evaluate the use of xanthene dyes as a potential alternative to malathion in protein bait sprays for the suppression of the Mediterranean fruit fly (Liquido et al. 1995). Light-activated toxicity of xanthene dyes has been documented for more than two dozen insect species overall (Heitz 1997). Field trials of xanthene dyes, as a safer alternative to malathion in bait sprays targeting the Mediterranean fruit fly, were begun in Hawaii in 1994 and in Guatemala in 1996 and proved to be promising. By the end of 1996, xanthene dyes were registered as a substitute for malathion to suppress/eradicate Mediterranean fruit flies in the barrier zone. In January, 1997, MOSCAMED-Guatemala began a spray programme with xanthene dyes as the toxicant in a protein bait

Intermediate Scale Laboratory Testing to Understand Mechanisms of Capillary and Dissolution Trapping during Injection and Post-Injection of CO₂ in Heterogeneous Geological Formations

Energy Technology Data Exchange (ETDEWEB)

Illangasekare, Tissa [Colorado School of Mines, Golden, CO (United States); Trevisan, Luca [Colorado School of Mines, Golden, CO (United States); Agartan, Elif [Colorado School of Mines, Golden, CO (United States); Mori, Hiroko [Colorado School of Mines, Golden, CO (United States); Vargas-Johnson, Javier [Colorado School of Mines, Golden, CO (United States); Gonzalez-Nicolas, Ana [Colorado School of Mines, Golden, CO (United States); Cihan, Abdullah [Colorado School of Mines, Golden, CO (United States); Birkholzer, Jens [Colorado School of Mines, Golden, CO (United States); Zhou, Quanlin [Colorado School of Mines, Golden, CO (United States)

2015-03-31

Carbon Capture and Storage (CCS) represents a technology aimed to reduce atmospheric loading of CO₂ from power plants and heavy industries by injecting it into deep geological formations, such as saline aquifers. A number of trapping mechanisms contribute to effective and secure storage of the injected CO₂ in supercritical fluid phase (scCO₂) in the formation over the long term. The primary trapping mechanisms are structural, residual, dissolution and mineralization. Knowledge gaps exist on how the heterogeneity of the formation manifested at all scales from the pore to the site scales affects trapping and parameterization of contributing mechanisms in models. An experimental and modeling study was conducted to fill these knowledge gaps. Experimental investigation of fundamental processes and mechanisms in field settings is not possible as it is not feasible to fully characterize the geologic heterogeneity at all relevant scales and gathering data on migration, trapping and dissolution of scCO₂. Laboratory experiments using scCO₂ under ambient conditions are also not feasible as it is technically challenging and cost prohibitive to develop large, two- or three-dimensional test systems with controlled high pressures to keep the scCO₂ as a liquid. Hence, an innovative approach that used surrogate fluids in place of scCO₂ and formation brine in multi-scale, synthetic aquifers test systems ranging in scales from centimeter to meter scale developed used. New modeling algorithms were developed to capture the processes controlled by the formation heterogeneity, and they were tested using the data from the laboratory test systems. The results and findings are expected to contribute toward better conceptual models, future improvements to DOE numerical codes, more accurate assessment of storage capacities, and optimized placement strategies. This report presents the experimental and modeling methods

Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source

Science.gov (United States)

2016-11-29

AFRL-AFOSR-VA-TR-2016-0365 Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source Jerome Moloney...SUBTITLE "Long Wavelength Electromagnetic Light Bullets Generated by a 10.6 micron CO2 Ultrashort Pulsed Source 5a. CONTRACT NUMBER FA9550-15-1-0272 5b...Wavelength Electromagnetic Light Bullets Generated by a 10 µm CO2 Ultrashort Pulsed Source Grant/Contract Number AFOSR assigned control number. It must

Low temperature luminescence and charge carrier trapping in a cryogenic scintillator Li{sub 2}MoO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Spassky, D.A., E-mail: deris2002@mail.ru [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); Skobeltsyn Institute of Nuclear Physics, Moscow State University, 119991 Moscow (Russian Federation); Nagirnyi, V. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); Savon, A.E. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, 119991 Moscow (Russian Federation); Kamenskikh, I.A. [Physics Faculty, Moscow State University, 119991 Moscow (Russian Federation); Barinova, O.P.; Kirsanova, S.V. [D. Mendeleyev University of Chemical Technology of Russia, 125047 Moscow (Russian Federation); Grigorieva, V.D.; Ivannikova, N.V.; Shlegel, V.N. [Nikolaev Institute of Inorganic Chemistry, SB RAS, 630090 Novosibirsk (Russian Federation); Aleksanyan, E. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); A.Alikhanyan National Science Laboratory, 2 Br. Alikhanyan Str., 0036 Yerevan (Armenia); Yelisseyev, A.P. [Sobolev Institute of Geology and Mineralogy, SB RAS, 630090 Novosibirsk (Russian Federation); Belsky, A. [Institute of Light and Matter, CNRS, University Lyon1, 69622 Villeurbanne (France)

2015-10-15

The luminescence and optical properties of promising cryogenic scintillator Li{sub 2}MoO{sub 4} were studied in the temperature region of 2–300 K. The data on luminescence spectra and decay characteristics, excitation spectra, thermostimulated luminescence curves and spectra as well as transmission and reflectivity spectra are presented for the single crystals grown by two different procedures, the conventional Czochralski method and the low-temperature gradient Czochralski technique. The bandgap of Li{sub 2}MoO{sub 4} is estimated from the analysis of transmission, luminescence excitation and reflectivity spectra. Up to three luminescence bands with the maxima at 1.98, 2.08 and 2.25 eV are detected in the emission spectra of crystals and their origin is discussed. In the thermoluminescence curves of both studied crystals, two high-intensity peaks were observed at 22 and 42 K, which are ascribed to the thermal release of self-trapped charge carriers. The coexistence of self-trapped electrons and holes allows one to explain the poor scintillation light yield of Li{sub 2}MoO{sub 4} at low temperatures. - Highlights: • Single crystals of Li{sub 2}MoO{sub 4} were grown by two methods. • The transparency cutoff (~4.3 eV) and bandgap values (<4.9 eV) are estimated. • The emission 2.08 eV is ascribed to self-trapped excitons and quenches at T>7 K. • Shallow traps considerably influence the energy transfer to emission centres. • Co-existence of self-trapped holes and electrons results in a low light yield.

Nutrient concentrations in a Littorella uniflora community at higher CO₂ concentrations and reduced light intensities

DEFF Research Database (Denmark)

Andersen, T.; Pedersen, O.; Andersen, F. Ø.

2005-01-01

laboratory experiments with isoetid vegetation (Littorella uniflora) where water column CO2 and light could be manipulated in order to test whether (i) light and CO2 availability affect nutrient concentrations in isoetid vegetation, and (ii) if changes in light and CO2 climate affect fluxes of inorganic...... nitrogen (N) and phosphorus (P) from sediment to water column, which potentially could result in increased growth of epiphytic algae. 3. The results showed that the standing stocks of phosphorus and nitrogen in the L. uniflora vegetation were significantly influenced by CO2 concentration and light...... intensity. Both standing stocks of P and N were significantly higher in the mesocosm treatments with high CO2 concentration than in those at low CO2 concentration. Similarly, standing stocks of P and N enhanced with increasing light intensity. 4. Measurements of nutrient fluxes both in the field...

Capturing [11C]CO2 for use in aqueous applications

International Nuclear Information System (INIS)

Vandehey, Nicholas T.; O’Neil, James P.

2014-01-01

We present a simple method for trapping [ 11 C]CO 2 gas and releasing it into a buffered solution using an ion-exchange cartridge. Sodium hydroxide cartridges captured >99% of [ 11 C]CO 2 following NaOH activation. A sodium bicarbonate solution eluted >99% of trapped radioactivity. Trapping [ 11 C]CO 2 directly in small volumes of several solutions was less effective than cartridge methods. The recommended methods allow for fast and simple production of highly concentrated carbon-11 containing aqueous solutions for use in filling phantoms, calibrating detectors, or (bio)geochemical experiments. - Highlights: • An ion exchange resin can trap [ 11 C]CO 2 gas and release it with saturated bicarbonate. • Elution from cartridge requires as little as 300 µL volume, with eluant at pH=10. • SPE trap-and-release provided better results than trapping in solution

The effect of light supply on microalgal growth, CO2 uptake and nutrient removal from wastewater

International Nuclear Information System (INIS)

Gonçalves, A.L.; Simões, M.; Pires, J.C.M.

2014-01-01

Highlights: • Effect of irradiance and light:dark ratio on microalgal growth was analysed. • Microalgal growth, CO 2 capture, nitrogen and phosphorus uptake were evaluated. • Higher irradiances and light periods supported higher growth and CO 2 uptake rates. • All the studied microalgal strains have shown high nitrogen removal efficiencies. • The highest phosphorus removal efficiency was 67.6%. - Abstract: Microalgal based biofuels have been reported as an attractive alternative for fossil fuels, since they constitute a renewable energy source that reduces greenhouse gas emissions to the atmosphere. However, producing biofuels from microalgae is still not economically viable. Therefore, the integration of biofuel production with other microalgal applications, such as CO 2 capture and nutrient removal from wastewaters, would reduce the microalgal production costs (and the environmental impact of cultures), increasing the economic viability of the whole process. Additionally, producing biofuels from microalgae strongly depends on microalgal strain and culture conditions. This study evaluates the effect of culture conditions, namely light irradiance (36, 60, 120 and 180 μE m −2 s −1 ) and light:dark ratio (10:14, 14:10 and 24:0), on microalgal growth, atmospheric CO 2 uptake and nutrient (nitrogen and phosphorous) removal from culture medium. Four different microalgal strains, Chlorella vulgaris, Pseudokirchneriella subcapitata, Synechocystis salina and Microcystis aeruginosa, were studied to ascertain the most advantageous regarding the referred applications. This study has shown that higher light irradiance values and light periods resulted in higher specific growth rates and CO 2 uptake rates. C. vulgaris presented the highest specific growth rate and CO 2 uptake rate: 1.190 ± 0.041 d −1 and 0.471 ± 0.047 g CO2 L −1 d −1 , respectively. All the strains have shown high nitrogen removal efficiencies, reaching 100% removal percentages in

Optical particle trapping and dynamic manipulation using spatial light modulation

DEFF Research Database (Denmark)

Eriksen, René Lynge

suitable for optical trapping. A phaseonly spatial light modulator (SLM) is used for the phase encoding of the laser beam. The SLM is controlled directly from a standard computer where phase information is represented as gray-scale image information. Experimentally, both linear and angular movements......This thesis deals with the spatial phase-control of light and its application for optical trapping and manipulation of micron-scale objects. Utilizing the radiation pressure, light exerts on dielectric micron-scale particles, functionality of optical tweezers can be obtained. Multiple intensity...... compression factors of two, which is not achievable with binary phase encoding, have been successfully demonstrated. In addition, the GPC method has been miniaturized and implemented in a planar optical platform and shown to work acceptably, with relatively high visibility. Furthermore, the GPC method has...

Enhanced photocatalytic properties of the 3D flower-like Mg-Al layered double hydroxides decorated with Ag{sub 2}CO{sub 3} under visible light illumination

Energy Technology Data Exchange (ETDEWEB)

Ao, Yanhui, E-mail: andyao@hhu.edu.cn; Wang, Dandan; Wang, Peifang; Wang, Chao; Hou, Jun; Qian, Jin

2016-08-15

Highlights: • 3D flower-like Ag{sub 2}CO{sub 3}/Mg-Al layered double hydroxide composite was prepared. • The nanocomposites exhibited high photocatalytic activities on different organic pollutants. • The mechanism of the enhanced activity were investigated. - Abstract: A facile anion-exchange precipitation method was employed to synthesize 3D flower-like Ag{sub 2}CO{sub 3}/Mg-Al layered double hydroxide composite photocatalyst. Results showed that Ag{sub 2}CO{sub 3} nanoparticles dispersed uniformly on the petals of the flower-like Mg-Al LDH. The obtained nanocomposites exhibited high photocatalytic activities on different organic pollutants (cationic and anionic dyes, phenol) under visible light illumination. The high photocatalytic activity can be ascribed to the special structure which accomplishes the wide-distribution of Ag{sub 2}CO{sub 3} nanoparticles on the surfaces of the 3D flower-like nanocomposites. Therefore, it can provide much more active sites for the degradation of organic pollutant. Then the photocatalytic mechanism was also verified by reactive species trapping experiments in detail. The work would pave a facile way to prepare LDHs based hierarchical photocatalysts with high activity for the degradation of wide range organic pollutants under visible light irradiation.

Hg-201 (+) CO-Magnetometer for HG-199(+) Trapped Ion Space Atomic Clocks

Science.gov (United States)

Burt, Eric A. (Inventor); Taghavi, Shervin (Inventor); Tjoelker, Robert L. (Inventor)

2011-01-01

Local magnetic field strength in a trapped ion atomic clock is measured in real time, with high accuracy and without degrading clock performance, and the measurement is used to compensate for ambient magnetic field perturbations. First and second isotopes of an element are co-located within the linear ion trap. The first isotope has a resonant microwave transition between two hyperfine energy states, and the second isotope has a resonant Zeeman transition. Optical sources emit ultraviolet light that optically pump both isotopes. A microwave radiation source simultaneously emits microwave fields resonant with the first isotope's clock transition and the second isotope's Zeeman transition, and an optical detector measures the fluorescence from optically pumping both isotopes. The second isotope's Zeeman transition provides the measure of magnetic field strength, and the measurement is used to compensate the first isotope's clock transition or to adjust the applied C-field to reduce the effects of ambient magnetic field perturbations.

Do Mound Disturbance and Bait Placement Affect Bait Removal and Treatment Efficacy in Red Imported Fire ant (Hymenoptera: Formicidae at Different Seasons?

Directory of Open Access Journals (Sweden)

Xing P. Hu

2009-01-01

Full Text Available This study provides empirical evidence that disturbing mound immediately before application, as opposed to label recommendation, did not reduce foraging activity of the red imported fire ant, Solenopsis invicta Buren, except for about 10-min delay in foraging. Despite the delayed foraging, there was no significant difference in the amount of baits foraged between disturbed and undisturbed colonies. Eventually, >96% of the baits were foraged, with the maximum removal occurred by 2 and 3 h, respectively, in summer and spring trial. The fastest and great amount of bait removal 1 h post-treatment occurred to baits placed on mound, followed by 0.18–0.3-m from mound base, and the slowest 1.08–1.2-m from mound base. All treatment gave 100% control 1 mo later, regardless of the season, without colony relocation or new colony invasion in the test plots.

Antioxidant capacity reduced in scallions grown under elevated CO 2 independent of assayed light intensity

Science.gov (United States)

Levine, Lanfang H.; Paré, Paul W.

2009-10-01

Long-duration manned space missions mandate the development of a sustainable life support system and effective countermeasures against damaging space radiation. To mitigate the risk of inevitable exposure to space radiation, cultivation of fresh fruits and vegetables rich in antioxidants is an attractive alternative to pharmacological agents. However it has yet to be established whether antioxidant properties of crops can be preserved or enhanced in a space environment where environmental conditions differ from that which plants have acclimated to on earth. Scallion ( Allium fistulosum) rich in antioxidant vitamins C and A, and flavonoids was used as a model plant to study the impact of a range of CO 2 concentrations and light intensities that are likely encountered in a space habitat on food quality traits. Scallions were hydroponically grown in controlled environmental chambers under a combination of 3 CO 2 concentrations of 400, 1200 and 4000 μmol mol -1 and 3 light intensity levels of 150, 300, 450 μmol m -2 s -1. Total antioxidant activity (TAA) of scallion extracts was determined using a radical cation scavenging assay. Both elevated CO 2 and increasing light intensity enhanced biomass accumulation, but effects on TAA (based on dry weight) differed. TAA was reduced for plants grown under elevated CO 2, but remained unchanged with increases in light intensity. Elevated CO 2 stimulated greater biomass production than antioxidants, while an increase in photosynthetic photo flux promoted the synthesis of antioxidant compounds at a rate similar to that of biomass. Consequently light is a more effective stimulus than CO 2 for antioxidant production.

The effect of light level, CO2 flow rate, and anesthesia on the stress response of mice during CO2 euthanasia.

Science.gov (United States)

Powell, Karin; Ethun, Kelly; Taylor, Douglas K

2016-09-21

Euthanasia protocols are designed to mitigate the stress experienced by animals, and an environment that induces minimal stress helps achieve that goal. A protocol that is efficient and practical in a typical animal research facility is also important. Light intensity, isoflurane, and CO2 flow rate were studied for their impact on the stress response of mice during CO2 euthanasia. Behavior was observed and scored during euthanasia and serum corticosterone was measured immediately after death. Unsurprisingly, animals euthanized with a high-flow rate of CO2 became unconscious in the least amount of time, while animals euthanized with a low-flow rate required the most time to reach unconsciousness. There was a significant increase in anxious behaviors in animals in the isoflurane group (F1,12 = 6.67, P = 0.024), the high-flow rate CO2 group (F1,12 = 10.24, P = 0.007), and bright chamber group (F1,12 = 7.27, P = 0.019). Serum corticosterone was highest in the isoflurane group (124.72 ± 83.98 ng/ml), however there was no significant difference in corticosterone levels observed for the other study variables of light and flow-rate. A darkened chamber and low CO2 flow rates help to decrease stress experienced during CO2 euthanasia, while the use of isoflurane was observed to increase the stress response during euthanasia.

Trap-assisted and Langevin-type recombination in organic light-emitting diodes

NARCIS (Netherlands)

Wetzelaer, G. A. H.; Kuik, M.; Nicolai, H. T.; Blom, P. W. M.

2011-01-01

Trapping of charges is known to play an important role in the charge transport of organic semiconductors, but the role of traps in the recombination process has not been addressed. Here we show that the ideality factor of the current of organic light-emitting diodes (OLEDs) in the

Bait effects in sampling coral reef fish assemblages with stereo-BRUVs.

Directory of Open Access Journals (Sweden)

Stacey R Dorman

Full Text Available Baited underwater video techniques are increasingly being utilised for assessing and monitoring demersal fishes because they are: 1 non extractive, 2 can be used to sample across multiple habitats and depths, 3 are cost effective, 4 sample a broader range of species than many other techniques, 5 and with greater statistical power. However, an examination of the literature demonstrates that a range of different bait types are being used. The use of different types of bait can create an additional source of variability in sampling programs. Coral reef fish assemblages at the Houtman Abrolhos Islands, Western Australia, were sampled using baited remote underwater stereo-video systems. One-hour stereo-video recordings were collected for four different bait treatments (pilchards, cat food, falafel mix and no bait (control from sites inside and outside a targeted fishery closure (TFC. In total, 5209 individuals from 132 fish species belonging to 41 families were recorded. There were significant differences in the fish assemblage structure and composition between baited and non-baited treatments (P<0.001, while no difference was observed with species richness. Samples baited with cat food and pilchards contained similar ingredients and were found to record similar components of the fish assemblage. There were no significant differences in the fish assemblages in areas open or closed to fishing, regardless of the bait used. Investigation of five targeted species indicated that the response to different types of bait was species-specific. For example, the relative abundance of Pagrus auratus was found to increase in areas protected from fishing, but only in samples baited with pilchards and cat food. The results indicate that the use of bait in conjunction with stereo-BRUVs is advantageous. On balance, the use of pilchards as a standardised bait for stereo-BRUVs deployments is justified for use along the mid-west coast of Western Australia.

Comparison of volatiles and mosquito capture efficacy for three carbohydrate sources in a yeast-fermentation CO2 generator

Science.gov (United States)

Mosquito surveillance in remote areas with limited access to canisters of CO2 or dry ice will benefit from an effective alternative CO2 source. In this study, we document the differences in mosquito and non-mosquito capture rates from CO2 baited (dry ice or yeast fermentation of carbohydrates) CDC t...

Deuterium trapping in the carbon-silicon co-deposition layers prepared by RF sputtering in D2 atmosphere

Science.gov (United States)

Zhang, Hongliang; Zhang, Weiyuan; Su, Ranran; Tu, Hanjun; Shi, Liqun; Hu, Jiansheng

2018-04-01

Deuterated carbon-silicon layers co-deposited on graphite and silicon substrates by radio frequency magnetron sputtering in pure D2 plasma were produced to study deuterium trapping and characteristics of the C-Si layers. The C-Si co-deposited layers were examined by ion beam analysis (IBA), Raman spectroscopy (RS), infrared absorption (IR) spectroscopy, thermal desorption spectroscopy (TDS) and scanning electron microscopy (SEM). It was found that the growth rate of the C-Si co-deposition layer decreased with increasing temperature from 350 K to 800 K, the D concentration and C/Si ratios increased differently on graphite and silicon substrates. TDS shows that D desorption is mainly as D2, HD, HDO, CD4, and C2D4 and release peaks occurred at temperatures of less than 900 K. RS and IR analysis reveal that the structure of the C-Si layers became more disordered with increasing temperatures. Rounded areas of peeling with 1-2 μm diameters were observed on the surface.

Integrated optimization of temperature, CO2, screen use and artificial lighting in greenhouse crops

DEFF Research Database (Denmark)

Aaslyng, J.M.; Körner, O.; Andreassen, A.U.

2005-01-01

A leaf photosynthesis model is suggested for integrated optimization of temperature, CO2, screen use and artificial lighting in greenhouse crops. Three different approaches for the optimization are presented. First, results from greenhouse experiments with model based optimization are presented....... Second, a model-based analysis of a commercial grower's production possibility is shown. Third, results from a simulation of the effect of a new lighting strategy are demonstrated. The results demonstrate that it is possible to optimize plant production by using a model-based integrated optimization...... of temperature, CO2, and light in the greenhouse...

A sublimation technique for high-precision measurements of δ13CO2 and mixing ratios of CO2 and N2O from air trapped in ice cores

Directory of Open Access Journals (Sweden)

H. Fischer

2011-07-01

Full Text Available In order to provide high precision stable carbon isotope ratios (δ13CO2 or δ13C of CO2 from small bubbly, partially and fully clathrated ice core samples we developed a new method based on sublimation coupled to gas chromatography-isotope ratio mass spectrometry (GC-IRMS. In a first step the trapped air is quantitatively released from ~30 g of ice and CO2 together with N2O are separated from the bulk air components and stored in a miniature glass tube. In an off-line step, the extracted sample is introduced into a helium carrier flow using a minimised tube cracker device. Prior to measurement, N2O and organic sample contaminants are gas chromatographically separated from CO2. Pulses of a CO2/N2O mixture are admitted to the tube cracker and follow the path of the sample through the system. This allows an identical treatment and comparison of sample and standard peaks. The ability of the method to reproduce δ13C from bubble and clathrate ice is verified on different ice cores. We achieve reproducibilities for bubble ice between 0.05 ‰ and 0.07 ‰ and for clathrate ice between 0.05 ‰ and 0.09 ‰ (dependent on the ice core used. A comparison of our data with measurements on bubble ice from the same ice core but using a mechanical extraction device shows no significant systematic offset. In addition to δ13C, the CO2 and N2O mixing ratios can be volumetrically derived with a precision of 2 ppmv and 8 ppbv, respectively.

Trapping guidelines for area-wide fruit fly programmes

International Nuclear Information System (INIS)

2003-11-01

Different traps and lures have been developed and used over decades to survey fruit fly populations. The first attractant for male fruit flies was methyl eugenol (ME) (for Bactrocera zonata, Howlett, 1912) followed by kerosene for Mediterranean fruit fly, Ceratitis capitata, (medfly), Severin and Severin, 1913. In 1956, Angelica seed oil was used to trap medfly (Steiner et al, 1957). Beroza et al. (1961) discovered trimedlure (TML) to be effective for the same purpose. Beroza and Green, 1963, demonstrated cuelure to be an effective attractant for Bactrocera cucurbitae. Food baits based on protein solutions, fermenting sugar solutions, fruit juices, and vinegar have been used since 1918 for the capture of females of several species. The McPhail trap was the first device to be used with protein baits (McPhail, 1929). Steiner traps were developed in 1957 (Steiner et al., 1957) and Jackson traps in 1971 for TML (Harris et al., 1971). These traps are currently used in various countries for fruit fly surveys in support of control activities and eradication campaigns. The combination of a McPhail trap with a protein attractant, Jackson trap with TML, and the Steiner trap with ME or cuelure (CUE), has remained unchanged for several decades. Global trends in increasing food quality, revenue sources, and fruit and vegetable trade, has resulted in an increased worldwide movement of fruit fly species and requires refinement of survey systems. After years of validating trapping technology through coordinated research programmes (CRP's) and extensive technical assistance to member countries, the Joint Division FAO/IAEA proposes the use of proven technologies in improving trap sensitivity in area-wide fruit fly control programmes (IAEA 1996 and IAEA 1998). These proven technologies include the use of synthetic food lures such as female attractants that can be used for several species of Anastrepha, Bactrocera and Ceratitis. Other citations of information on these developments are

Trapping guidelines for area-wide fruit fly programmes

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-11-01

Different traps and lures have been developed and used over decades to survey fruit fly populations. The first attractant for male fruit flies was methyl eugenol (ME) (for Bactrocera zonata, Howlett, 1912) followed by kerosene for Mediterranean fruit fly, Ceratitis capitata, (medfly), Severin and Severin, 1913. In 1956, Angelica seed oil was used to trap medfly (Steiner et al, 1957). Beroza et al. (1961) discovered trimedlure (TML) to be effective for the same purpose. Beroza and Green, 1963, demonstrated cuelure to be an effective attractant for Bactrocera cucurbitae. Food baits based on protein solutions, fermenting sugar solutions, fruit juices, and vinegar have been used since 1918 for the capture of females of several species. The McPhail trap was the first device to be used with protein baits (McPhail, 1929). Steiner traps were developed in 1957 (Steiner et al., 1957) and Jackson traps in 1971 for TML (Harris et al., 1971). These traps are currently used in various countries for fruit fly surveys in support of control activities and eradication campaigns. The combination of a McPhail trap with a protein attractant, Jackson trap with TML, and the Steiner trap with ME or cuelure (CUE), has remained unchanged for several decades. Global trends in increasing food quality, revenue sources, and fruit and vegetable trade, has resulted in an increased worldwide movement of fruit fly species and requires refinement of survey systems. After years of validating trapping technology through coordinated research programmes (CRP's) and extensive technical assistance to member countries, the Joint Division FAO/IAEA proposes the use of proven technologies in improving trap sensitivity in area-wide fruit fly control programmes (IAEA 1996 and IAEA 1998). These proven technologies include the use of synthetic food lures such as female attractants that can be used for several species of Anastrepha, Bactrocera and Ceratitis. Other citations of information on these developments are

Elimination of Coptotermes lacteus (Froggatt) (Blattodea: Rhinotemitidae) Colonies Using Bistrifluron Bait Applied through In-Ground Bait Stations Surrounding Mounds.

Science.gov (United States)

Webb, Garry

2017-09-12

The efficacy of bistrifluron termite bait was evaluated using in-ground bait stations placed around Coptotermes lacteus mounds in south-eastern Australia during late summer and autumn (late February to late May 2012). Four in-ground bait stations containing timber billets were placed around each of twenty mounds. Once sufficient numbers of in-ground stations were infested by termites, mounds were assigned to one of four groups (one, two, three or four 120 g bait canisters or 120 to 480 g bait in total per mound) and bait canisters installed. One mound, nominally assigned treatment with two canisters ultimately had no termite interception in any of the four in-ground stations and not treated. Eighteen of the remaining 19 colonies were eliminated by 12 weeks after bait placement, irrespective of bait quantity removed (range 43 to 480 g). Measures of colony decline-mound repair capability and internal core temperature-did not accurately reflect the colony decline, as untreated colonies showed a similar pattern of decline in both repair capability and internal mound core temperature. However, during the ensuing spring-summer period, capacity to repair the mound was restored in untreated colonies and the internal core temperature profile was similar to the previous spring-summer period which indicated that these untreated colonies remained healthy.

Mass mosquito trapping for malaria control in western Kenya

NARCIS (Netherlands)

Hiscox, Alexandra; Homan, Tobias; Mweresa, Collins K.; Maire, Nicolas; Pasquale, Di Aurelio; Masiga, Daniel; Oria, Prisca A.; Alaii, Jane; Leeuwis, Cees; Mukabana, Wolfgang R.; Takken, Willem; Smith, Thomas A.

2016-01-01

Background: Increasing levels of insecticide resistance as well as outdoor, residual transmission of malaria threaten the efficacy of existing vector control tools used against malaria mosquitoes. The development of odour-baited mosquito traps has led to the possibility of controlling malaria

Visible-light-driven methane formation from CO2 with a molecular iron catalyst

Science.gov (United States)

Rao, Heng; Schmidt, Luciana C.; Bonin, Julien; Robert, Marc

2017-08-01

Converting CO2 into fuel or chemical feedstock compounds could in principle reduce fossil fuel consumption and climate-changing CO2 emissions. One strategy aims for electrochemical conversions powered by electricity from renewable sources, but photochemical approaches driven by sunlight are also conceivable. A considerable challenge in both approaches is the development of efficient and selective catalysts, ideally based on cheap and Earth-abundant elements rather than expensive precious metals. Of the molecular photo- and electrocatalysts reported, only a few catalysts are stable and selective for CO2 reduction; moreover, these catalysts produce primarily CO or HCOOH, and catalysts capable of generating even low to moderate yields of highly reduced hydrocarbons remain rare. Here we show that an iron tetraphenylporphyrin complex functionalized with trimethylammonio groups, which is the most efficient and selective molecular electro- catalyst for converting CO2 to CO known, can also catalyse the eight-electron reduction of CO2 to methane upon visible light irradiation at ambient temperature and pressure. We find that the catalytic system, operated in an acetonitrile solution containing a photosensitizer and sacrificial electron donor, operates stably over several days. CO is the main product of the direct CO2 photoreduction reaction, but a two-pot procedure that first reduces CO2 and then reduces CO generates methane with a selectivity of up to 82 per cent and a quantum yield (light-to-product efficiency) of 0.18 per cent. However, we anticipate that the operating principles of our system may aid the development of other molecular catalysts for the production of solar fuels from CO2 under mild conditions.

Periodic molybdenum disc array for light trapping in amorphous silicon layer

Energy Technology Data Exchange (ETDEWEB)

Wang, Jiwei; Deng, Changkai [International Center of Quantum and Molecular Structures, Materials Genome Institute, and Department of Physics, Shanghai University, 99 Shangda Road, Shanghai, 200444 China (China); Shanghai Advanced Research Institute, Chinese Academy of Sciences, 99 Haike Road, Shanghai, 201210 China (China); Yang, Kang; Chen, Haiyan, E-mail: chenhy@sari.ac.cn; Li, Dongdong; Chen, Xiaoyuan [Shanghai Advanced Research Institute, Chinese Academy of Sciences, 99 Haike Road, Shanghai, 201210 China (China); Ren, Wei, E-mail: renwei@shu.edu.cn [International Center of Quantum and Molecular Structures, Materials Genome Institute, and Department of Physics, Shanghai University, 99 Shangda Road, Shanghai, 200444 China (China)

2016-05-15

We demonstrate the light trapping effect in amorphous silicon (a-Si:H) layer by inserting a layer of periodic molybdenum disc array (MDA) between the a-Si:H layer and the quartz substrate, which forms a three-layer structure of Si/MDA/SiO{sub 2}. The MDA layer was fabricated by a new cost-effective method based on nano-imprint technology. Further light absorption enhancement was realized through altering the topography of MDA by annealing it at 700°C. The mechanism of light absorption enhancement in a-Si:H interfaced with MDA was analyzed, and the electric field distribution and light absorption curve of the different layers in the Si/MDA structure under light illumination of different wavelengths were simulated by employing numerical finite difference time domain (FDTD) solutions.

How light, temperature, and measurement and growth [CO2] interactively control isoprene emission in hybrid aspen.

Science.gov (United States)

Niinemets, Ülo; Sun, Zhihong

2015-02-01

Plant isoprene emissions have been modelled assuming independent controls by light, temperature and atmospheric [CO2]. However, the isoprene emission rate is ultimately controlled by the pool size of its immediate substrate, dimethylallyl diphosphate (DMADP), and isoprene synthase activity, implying that the environmental controls might interact. In addition, acclimation to growth [CO2] can shift the share of the control by DMADP pool size and isoprene synthase activity, and thereby alter the environmental sensitivity. Environmental controls of isoprene emission were studied in hybrid aspen (Populus tremula × Populus tremuloides) saplings acclimated either to ambient [CO2] of 380 μmol mol(-1) or elevated [CO2] of 780 μmol mol(-1). The data demonstrated strong interactive effects of environmental drivers and growth [CO2] on isoprene emissions. Light enhancement of isoprene emission was the greatest at intermediate temperatures and was greater in elevated-[CO2]-grown plants, indicating greater enhancement of the DMADP supply. The optimum temperature for isoprene emission was higher at lower light, suggesting activation of alternative DMADP sinks at higher light. In addition, [CO2] inhibition of isoprene emission was lost at a higher temperature with particularly strong effects in elevated-[CO2]-grown plants. Nevertheless, DMADP pool size was still predicted to more strongly control isoprene emission at higher temperatures in elevated-[CO2]-grown plants. We argue that interactive environmental controls and acclimation to growth [CO2] should be incorporated in future isoprene emission models at the level of DMADP pool size. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Bait effects in sampling coral reef fish assemblages with stereo-BRUVs.

Science.gov (United States)

Dorman, Stacey R; Harvey, Euan S; Newman, Stephen J

2012-01-01

Baited underwater video techniques are increasingly being utilised for assessing and monitoring demersal fishes because they are: 1) non extractive, 2) can be used to sample across multiple habitats and depths, 3) are cost effective, 4) sample a broader range of species than many other techniques, 5) and with greater statistical power. However, an examination of the literature demonstrates that a range of different bait types are being used. The use of different types of bait can create an additional source of variability in sampling programs. Coral reef fish assemblages at the Houtman Abrolhos Islands, Western Australia, were sampled using baited remote underwater stereo-video systems. One-hour stereo-video recordings were collected for four different bait treatments (pilchards, cat food, falafel mix and no bait (control)) from sites inside and outside a targeted fishery closure (TFC). In total, 5209 individuals from 132 fish species belonging to 41 families were recorded. There were significant differences in the fish assemblage structure and composition between baited and non-baited treatments (Pcat food and pilchards contained similar ingredients and were found to record similar components of the fish assemblage. There were no significant differences in the fish assemblages in areas open or closed to fishing, regardless of the bait used. Investigation of five targeted species indicated that the response to different types of bait was species-specific. For example, the relative abundance of Pagrus auratus was found to increase in areas protected from fishing, but only in samples baited with pilchards and cat food. The results indicate that the use of bait in conjunction with stereo-BRUVs is advantageous. On balance, the use of pilchards as a standardised bait for stereo-BRUVs deployments is justified for use along the mid-west coast of Western Australia.

Effectiveness of bait tubes for brown treesnake control on Guam

Science.gov (United States)

Lardner, B.; Savidge, J.A.; Rodda, G.H.; Reed, R.N.; Yackel Adams, A.A.; Clark, C.S.

2011-01-01

A bait tube is a device with which a toxicant inserted in a dead mouse (Mus musculus) can be delivered to invasive brown treesnakes (Boiga irregularis) with low risk of non-target bait take. We tested two bait tube designs in a 5ha snake enclosure where the identity of virtually every snake is known. Instead of using toxicants, we implanted radio transmitters in small (6.6±1.4 g) and large (21.8±2.9 g) bait mice. Knowing all snakes present in the population allowed us to characterize not only covariates of snakes taking bait, but also those of snakes evading our mock control effort, and if snake covariates interacted with any design variable in determining targeting rate. Tube design had no effect on take rate. Snake snout-vent length was a strong predictor of success: none of the 29 snakes smaller than 843 mm took any bait, while the 126 snakes ≥843 mm were responsible for a total of 164 bait takes. The smallest of these snakes were able to ingest small and large mice, but tended to consume small bait at a higher rate than large bait. The main reason for our failure to target smallest snakes appears not to be gape limitation, but rather that small snakes prefer other prey (lizards). The time it takes a snake to grow from the size threshold observed to the size of maturation has implications for the interval between discrete efforts using toxic bait. Targeting all snakes before reproduction can occur is highly desirable; otherwise, a new cohort of refractory snakes may enter the population.

Modeling of fate and transport of co-injection of H2S with CO2 in deep saline formations

Energy Technology Data Exchange (ETDEWEB)

Zhang, W.; Xu, T.; Li, Y.

2010-12-15

The geological storage of CO{sub 2} in deep saline formations is increasing seen as a viable strategy to reduce the release of greenhouse gases into the atmosphere. However, costs of capture and compression of CO{sub 2} from industrial waste streams containing small quantities of sulfur and nitrogen compounds such as SO{sub 2}, H{sub 2}S and N{sub 2} are very expensive. Therefore, studies on the co-injection of CO{sub 2} containing other acid gases from industrial emissions are very important. In this paper, numerical simulations were performed to study the co-injection of H{sub 2}S with CO{sub 2} in sandstone and carbonate formations. Results indicate that the preferential dissolution of H{sub 2}S gas (compared with CO{sub 2} gas) into formation water results in the delayed breakthrough of H{sub 2}S gas. Co-injection of H{sub 2}S results in the precipitation of pyrite through interactions between the dissolved H{sub 2}S and Fe{sup 2+} from the dissolution of Fe-bearing minerals. Additional injection of H{sub 2}S reduces the capabilities for solubility and mineral trappings of CO{sub 2} compared to the CO{sub 2} only case. In comparison to the sandstone (siliciclastic) formation, the carbonate formation is less favorable to the mineral sequestration of CO{sub 2}. Different from CO{sub 2} mineral trapping, the presence of Fe-bearing siliciclastic and/or carbonate is more favorable to the H{sub 2}S mineral trapping.

16 CFR 238.0 - Bait advertising defined. 1

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Bait advertising defined. 1 238.0 Section... BAIT ADVERTISING § 238.0 Bait advertising defined. 1 1 For the purpose of this part “advertising” includes any form of public notice however disseminated or utilized. Bait advertising is an alluring but...

Kinetics of light sum collection in solid dosemeters with several trapping levels

International Nuclear Information System (INIS)

Vlasov, V.K.; Tarasov, M.Yu.

1983-01-01

On the basis of a stochastic model of filling up the electron-hole capture centres following irradiation, the kinetics of light sum accumulation in crystallophosphors with any number of capture levels has been considered. Using as an example a crystallophosphor with two hole- and two electron capture centres, solution of equations for the kinetics of light sum accumulation in solid dosemeters is presented. It is shown that in the presence of two competing capture centres the filling-up of one of the traps is always described by the function with a bent and superlinear section, whereas the filling-up of the competing trap is described by the function without a bent. The dose-effect functional relationship for competing traps does not depend either on the energetic depth of the trap or absolute values of capture micro cross-sections, but depends solely on relative values of macro- and micro cross-sections for competing traps. The theoretical model has been checked when studying radiothermoluminescence of synthetic quartz. The experimental results are shown to agree well with the model suggested

Experimental Investigation on the Behavior of Supercritical CO2 during Reservoir Depressurization.

Science.gov (United States)

Li, Rong; Jiang, Peixue; He, Di; Chen, Xue; Xu, Ruina

2017-08-01

CO 2 sequestration in saline aquifers is a promising way to address climate change. However, the pressure of the sequestration reservoir may decrease in practice, which induces CO 2 exsolution and expansion in the reservoir. In this study, we conducted a core-scale experimental investigation on the depressurization of CO 2 -containing sandstone using NMR equipment. Three different series of experiments were designed to investigate the influence of the depressurization rate and the initial CO2 states on the dynamics of different trapping mechanisms. The pressure range of the depressurization was from 10.5 to 4.0 MPa, which covered the supercritical and gaseous states of the CO 2 (named as CO 2 (sc) and CO 2 (g), respectively). It was found that when the aqueous phase saturated initially, the exsolution behavior strongly depended on the depressurization rate. When the CO 2 and aqueous phase coexisting initially, the expansion of the CO 2 (sc/g) contributed to the incremental CO 2 saturation in the core only when the CO 2 occurred as residually trapped. It indicates that the reservoir depressurization has the possibility to convert the solubility trapping to the residual trapping phase, and/or convert the residual trapping to mobile CO 2 .

Concepts for external light trapping and its utilization in colored and image displaying photovoltaic modules

NARCIS (Netherlands)

van Dijk, L.; van de Groep, J.; Veldhuizen, L.W.; Di Vece, M.; Schropp, R.E.I.

2017-01-01

The reflection of incident sunlight prevents photovoltaic modules from reaching their full energy conversion potential. Recently, we demonstrated significant absorption enhancement in various solar cells by external light trapping, using 3D-printed and milled light traps. In order to facilitate

3D-printed concentrator arrays for external light trapping on thin film solar cells

NARCIS (Netherlands)

van Dijk, Lourens; Marcus, E.A.P.; Oostra, A.J.; Schropp, R.E.I.; Vece, Di M.

2015-01-01

After our recent demonstration of a 3D-printed external light trap on a small solar cell, we now consider its potential for large solar panels. An external light trap consists of a parabolic concentrator and a spacer that redirects the photons that are reflected by the solar cell back towards the

3D-printed concentrator arrays for external light trapping on thin film solar cells

NARCIS (Netherlands)

van Dijk, Lourens; Marcus, E. A. Pepijn; Oostra, A. Jolt; Schropp, Ruud E. I.; Di Vece, Marcel

After our recent demonstration of a 3D-printed external light trap on a small solar cell, we now consider its potential for large solar panels. An external light trap consists of a parabolic concentrator and a spacer that redirects the photons that are reflected by the solar cell back towards the

Evanescent light-wave atom mirrors, resonators, waveguides, and traps

International Nuclear Information System (INIS)

Dowling, J.P.; Gea-Banacloche, J.

1996-01-01

For many years, it has been known that light can be used to trap and manipulate small dielectric particles and atoms. In particular, the intense coherent light of lasers has been used to cool neutral atoms down to the micro-Kelvin and now even the nano-Kelvin regimes. At such low temperatures, the de Broglie wavelike character of the atoms becomes pronounced, making it necessary to treat the atoms as wave phenomena. To this end, the study of atom optics has recently developed, in which atom optical elements are fabricated in order to manipulate atoms, while utilizing and preserving the coherence and superposition properties inherent in their wavelike propagation. For example, there has been a concerted effort to study theoretically and produce experimentally the atom optic analogs of photonic optical elements, such as atom beam splitters, atom diffraction gratings, atom lenses, atom interferometers, and-last but not least-atom mirrors. It is light-induced atom mirrors, and their application to making atom resonators, waveguides, and traps, that we shall focus on in this chapter. 133 refs., 26 figs., 1 tab

Quantum computing with trapped ions, atoms and light

International Nuclear Information System (INIS)

Steane, Andrew M.

2001-01-01

We consider experimental issues relevant to quantum computing, and discuss the best way to achieve the essential requirements of reliable quantum memory and gate operations. Nuclear spins in trapped ions or atoms are a very promising candidate for the qubits. We estimate the parameters required to couple atoms using light via cavity QED in order to achieve quantum gates. We briefly comment on recent improvements to the Cirac-Zoller method for coupling trapped ions via their vibrational degree of freedom. Error processes result in a trade-off between quantum gate speed and failure probability. A useful quantum computer does appear to be feasible using a combination of ion trap and optical methods. The best understood method to stabilize a large computer relies on quantum error correction. The essential ideas of this are discussed, and recent estimates of the noise requirements in a quantum computing device are given

Effect of CoFe magnetic nanoparticles on the hole transport in poly(2-methoxy, 5-(2-ethylhexiloxy) 1,4-phenylenevinylene)

International Nuclear Information System (INIS)

Kumar, Pankaj; Kumar, Hemant; Chand, Suresh; Jain, S C; Kumar, Vikram; Kumar, Vinod; Pant, R P; Tandon, R P

2008-01-01

The effect of doping of CoFe magnetic nanoparticles (MNPs) on the hole transport in poly(2-methoxy,5-(2-ethylhexyloxy)-1,4-phenylenevinylene)(MEH-PPV) thin films has been investigated in the temperature range 280-120 K. Hole transport in MEH-PPV is found to be governed by space-charge-limited-conduction (SCLC) with exponential distribution of traps in energy space. Doping of CoFe MNPs in MEH-PPV reduces the hole mobility from 1 x 10 -5 to 6 x 10 -6 cm 2 V -1 s -1 by introducing new trap sites causing their net density increase from 1 x 10 18 to 2.1 x 10 18 cm -3 , which is likely to result in balanced injection and efficient recombination of charge carriers to improve the performance of polymer light emitting diodes

Elimination of Coptotermes lacteus (Froggatt (Blattodea: Rhinotemitidae Colonies Using Bistrifluron Bait Applied through In-Ground Bait Stations Surrounding Mounds

Directory of Open Access Journals (Sweden)

Garry Webb

2017-09-01

Full Text Available The efficacy of bistrifluron termite bait was evaluated using in-ground bait stations placed around Coptotermes lacteus mounds in south-eastern Australia during late summer and autumn (late February to late May 2012. Four in-ground bait stations containing timber billets were placed around each of twenty mounds. Once sufficient numbers of in-ground stations were infested by termites, mounds were assigned to one of four groups (one, two, three or four 120 g bait canisters or 120 to 480 g bait in total per mound and bait canisters installed. One mound, nominally assigned treatment with two canisters ultimately had no termite interception in any of the four in-ground stations and not treated. Eighteen of the remaining 19 colonies were eliminated by 12 weeks after bait placement, irrespective of bait quantity removed (range 43 to 480 g. Measures of colony decline—mound repair capability and internal core temperature—did not accurately reflect the colony decline, as untreated colonies showed a similar pattern of decline in both repair capability and internal mound core temperature. However, during the ensuing spring–summer period, capacity to repair the mound was restored in untreated colonies and the internal core temperature profile was similar to the previous spring–summer period which indicated that these untreated colonies remained healthy.

Maximizing growth of vegetable seedlings in controlled environments at elevated temperature, light and CO/sub 2/

Energy Technology Data Exchange (ETDEWEB)

Krizek, D.T.; Bailey, W.A.; Klueter, H.; Liu, R.C.

1974-01-01

Seedlings of cucumber Burpee Hybrid, tomato Michigan-Ohio and lettuce Grand Rapids were germinated in the greenhouse for 5, 8, and 11 days respectively, and then grown for 15 days at elevated temperature (30/24/sup 0/C), light (43.1 klx), and CO/sub 2/ (2000 ppm) a 16-hr photoperiod, 65% relative humidity, and fertilized 4 times daily. At the end of this time, they weighed 2 to 4.6 times those grown at standard environmental conditions in the growth chamber (24/18/sup 0/C, 21.5 klx, and 400 ppm CO/sub 2/) and 10 to 25 times those of greenhouse controls kept on natural days (24/18/sup 0/C, 350 ppm CO/sub 2/, and ca 12-hr photoperiod). Leaf expansion of seedlings grown under elevated growth chamber conditions was double that of seedlings in standard growth chamber conditions, and 6 to 7 times greater than under natural days in the greenhouse. Temperature was the most limiting factor for seedling growth. At the levels of light and CO/sub 2/ used in the experiment, CO/sub 2/ was more limiting than light intensity. In general, optimum seedling growth was obtained when temperature, light, and CO/sub 2/ were increased simultaneously. The most striking effects of CO/sub 2/ enrichment were precocious flower bud formation in tomato and cucumber and extensive growth of the lateral buds in all three species.

Ultraviolet safety assessments of insect light traps.

Science.gov (United States)

Sliney, David H; Gilbert, David W; Lyon, Terry

2016-01-01

Near-ultraviolet (UV-A: 315-400 nm), "black-light," electric lamps were invented in 1935 and ultraviolet insect light traps (ILTs) were introduced for use in agriculture around that time. Today ILTs are used indoors in several industries and in food-service as well as in outdoor settings. With recent interest in photobiological lamp safety, safety standards are being developed to test for potentially hazardous ultraviolet emissions. A variety of UV "Black-light" ILTs were measured at a range of distances to assess potential exposures. Realistic time-weighted human exposures are shown to be well below current guidelines for human exposure to ultraviolet radiation. These UV-A exposures would be far less than the typical UV-A exposure in the outdoor environment. Proposals are made for realistic ultraviolet safety standards for ILT products.

Modeling light use efficiency in a subtropical mangrove forest equipped with CO2 eddy covariance

Directory of Open Access Journals (Sweden)

J. G. Barr

2013-03-01

Full Text Available Despite the importance of mangrove ecosystems in the global carbon budget, the relationships between environmental drivers and carbon dynamics in these forests remain poorly understood. This limited understanding is partly a result of the challenges associated with in situ flux studies. Tower-based CO2 eddy covariance (EC systems are installed in only a few mangrove forests worldwide, and the longest EC record from the Florida Everglades contains less than 9 years of observations. A primary goal of the present study was to develop a methodology to estimate canopy-scale photosynthetic light use efficiency in this forest. These tower-based observations represent a basis for associating CO2 fluxes with canopy light use properties, and thus provide the means for utilizing satellite-based reflectance data for larger scale investigations. We present a model for mangrove canopy light use efficiency utilizing the enhanced green vegetation index (EVI derived from the Moderate Resolution Imaging Spectroradiometer (MODIS that is capable of predicting changes in mangrove forest CO2 fluxes caused by a hurricane disturbance and changes in regional environmental conditions, including temperature and salinity. Model parameters are solved for in a Bayesian framework. The model structure requires estimates of ecosystem respiration (RE, and we present the first ever tower-based estimates of mangrove forest RE derived from nighttime CO2 fluxes. Our investigation is also the first to show the effects of salinity on mangrove forest CO2 uptake, which declines 5% per each 10 parts per thousand (ppt increase in salinity. Light use efficiency in this forest declines with increasing daily photosynthetic active radiation, which is an important departure from the assumption of constant light use efficiency typically applied in satellite-driven models. The model developed here provides a framework for estimating CO2 uptake by these forests from reflectance data and

Development of Bait Stations for Fruit Fly Suppression in Support of SIT. Working Material

International Nuclear Information System (INIS)

2009-01-01

A more economic and practical fruit fly suppression tool is needed to replace conventional aerial and ground bait sprays applications over human settlements, protected natural areas, and difficult to access areas where fruit fly hosts exist. This has been a major request from area-wide integrated pest management action programmes using the Sterile Insect Technique (SIT) as a component. In recent years, especially in Europe, most conventional insecticides used to control fruit pests have been banned (e.g. malathion, dichlorvos and other organophosphates), therefore areas producing fruits and vegetables for markets that request low insecticide residues or even fruit and vegetable organic farming is seeking for a more economic fruit fly control option to the spinosad-based bait sprays and to the use of mass trapping. To address these requests, bait stations can be one of the most suitable alternatives. The development of these devices needs to take into consideration cost-effectiveness, and long lasting attractants and killing agents, and should target female fruit flies. Recent developments of synthetic food attractants and long-lasting formulations open the possibility to improve the existent baits stations or develop new ones. With this objective the Insect Pest Control Subprogramme of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture organized a Consultants Meeting ('Development of Bait Stations for Fruit Fly Suppression in Support of SIT'), held in Mazatlan, Mexico, from 30 October to 1 November 2008, with the participation of 14 scientists from the Instituto Nacional de Tecnologia Agropecuaria, Argentina; Department of Primary Industries and Fisheries, Australia; North American Plant Protection Organization, Canada; African Insect Science for Food and Health, Kenya; Universidad Politecnica de Valencia, Spain; Institut de Recerca i Tecnologia Agroalimentaries, Spain, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y

Effects of elevated atmospheric CO2 concentration on leaf dark respiration of Xanthium strumarium in light and in darkness.

Science.gov (United States)

Wang, X; Lewis, J D; Tissue, D T; Seemann, J R; Griffin, K L

2001-02-27

Leaf dark respiration (R) is an important component of plant carbon balance, but the effects of rising atmospheric CO(2) on leaf R during illumination are largely unknown. We studied the effects of elevated CO(2) on leaf R in light (R(L)) and in darkness (R(D)) in Xanthium strumarium at different developmental stages. Leaf R(L) was estimated by using the Kok method, whereas leaf R(D) was measured as the rate of CO(2) efflux at zero light. Leaf R(L) and R(D) were significantly higher at elevated than at ambient CO(2) throughout the growing period. Elevated CO(2) increased the ratio of leaf R(L) to net photosynthesis at saturated light (A(max)) when plants were young and also after flowering, but the ratio of leaf R(D) to A(max) was unaffected by CO(2) levels. Leaf R(N) was significantly higher at the beginning but significantly lower at the end of the growing period in elevated CO(2)-grown plants. The ratio of leaf R(L) to R(D) was used to estimate the effect of light on leaf R during the day. We found that light inhibited leaf R at both CO(2) concentrations but to a lesser degree for elevated (17-24%) than for ambient (29-35%) CO(2)-grown plants, presumably because elevated CO(2)-grown plants had a higher demand for energy and carbon skeletons than ambient CO(2)-grown plants in light. Our results suggest that using the CO(2) efflux rate, determined by shading leaves during the day, as a measure for leaf R is likely to underestimate carbon loss from elevated CO(2)-grown plants.

Field Studies Evaluating Bait Acceptance and Handling by Free-Roaming Dogs in Thailand

Directory of Open Access Journals (Sweden)

Suwicha Kasemsuwan

2018-05-01

Full Text Available (1 Background: As part of the ongoing endeavor to eliminate dog-mediated human rabies in Thailand, renewed interest has been shown in oral vaccination of dogs as a supplementary tool to increase vaccination coverage of the dog population. (2 Methods: Three different bait types were tested using a hand-out model on the campus of the Kasetsart University and the surrounding temples in Thailand during September 2017, consisting of two industrial manufactured baits (fish meal and egg-flavored and one bait made from local material (boiled pig intestine placed in collagen casing. A PVC-capsule containing dyed water was inserted in the bait. (3 Results: The fishmeal bait was significantly less often accepted and consumed (50.29% than the other two baits (intestine bait—79.19%; egg bait—78.77%. Delivery and release of the dyed water in the oral cavity was highest in the egg-flavored bait (84.50%, followed by the intestine bait (76.61% and fishmeal (54.85% baits. Bait acceptance was influenced by sex, age, and body size of the dog. Also, the origin of the dogs had a significant effect: temple dogs accepted the baits more often than street dogs. (4 Conclusion: A significant portion of the free-roaming dog population in this study can be vaccinated by offering vaccine baits.

Fabrication of versatile cladding light strippers and fiber end-caps with CO2 laser radiation

Science.gov (United States)

Steinke, M.; Theeg, T.; Wysmolek, M.; Ottenhues, C.; Pulzer, T.; Neumann, J.; Kracht, D.

2018-02-01

We report on novel fabrication schemes of versatile cladding light strippers and end-caps via CO2 laser radiation. We integrated cladding light strippers in SMA-like connectors for reliable and stable fiber-coupling of high-power laser diodes. Moreover, the application of cladding light strippers in typical fiber geometries for high-power fiber lasers was evaluated. In addition, we also developed processes to fuse end-caps to fiber end faces via CO2 laser radiation and inscribe the fibers with cladding light strippers near the end-cap. Corresponding results indicate the great potential of such devices as a monolithic and low-cost alternative to SMA connectors.

Measurement of elastic light scattering from two optically trapped microspheres and red blood cells in a transparent medium.

Science.gov (United States)

Kinnunen, Matti; Kauppila, Antti; Karmenyan, Artashes; Myllylä, Risto

2011-09-15

Optical tweezers can be used to manipulate small objects and cells. A trap can be used to fix the position of a particle during light scattering measurements. The places of two separately trapped particles can also be changed. In this Letter we present elastic light scattering measurements as a function of scattering angle when two trapped spheres are illuminated with a He-Ne laser. This setup is suitable for trapping noncharged homogeneous spheres. We also demonstrate measurement of light scattering patterns from two separately trapped red blood cells. Two different illumination schemes are used for both samples.

Type approval and real-world CO_2 and NO_x emissions from EU light commercial vehicles

International Nuclear Information System (INIS)

Zacharof, Nikiforos; Tietge, Uwe; Franco, Vicente; Mock, Peter

2016-01-01

In the European Union, light duty vehicles (LDVs) are subject to emission targets for carbon dioxide (CO_2) and limits for pollutants such as nitrogen oxides (NO_x). CO_2 emissions are regulated for both passenger vehicles (PV) and light commercial vehicles (LCV), as individual manufacturers are required to reach fleet averages of 130 g/km by 2015 and 175 g/km by 2017, respectively. In the case of PVs, it has been found that there is a significant divergence between real-world and type-approval CO_2 emissions, which has been increasing annually, reaching 40% in 2014. On-road exceedances of regulated NO_x emission limits for diesel passenger cars have also been documented. The current study investigated the LCV characteristics and CO_2 and NO_x emissions in the European Union. A vehicle market analysis found that LCVs comprise 17% of the diesel LDV market and while there were some data for CO_2 emissions, there were hardly any data publicly available for NO_x emissions. Monitoring the divergence in CO_2 emissions revealed that it increased from 14% in 2006 to 33% in 2014, posing an additional annual fuel cost from 120€ in 2006 to 305€ in 2014, while a significant percentage of Euro 5 vehicles exceeded NO_x emission standards. - Highlights: • Light commercial vehicles comprise 17% of diesel light duty vehicle market. • On-road CO_2 emissions were found to be on average 33% higher than compared to type approval measurements. • The annual additional fuel cost due to the on-road and type approval divergence is estimated at 400€. • Data indicates exceedances in on-road NO_x emissions. • Little attention has been given to light commercial vehicles compared to passenger vehicles.

Impacts of silvicultural thinning treatments on beetle trap captures and tree attacks during low bark beetle populations in ponderosa pine forests of northern Arizona.

Science.gov (United States)

Gaylord, M L; Hofstetter, R W; Wagner, M R

2010-10-01

Our research used a combination of passive traps, funnel traps with lures, baited trees, and surveys of long-term thinning plots to assess the impacts of different levels of stand basal area (BA) on bark beetle tree attack and on trap captures of Ips spp., Dendroctonus spp., and their predators. The study occurred at two sites in ponderosa pine, Pinus ponderosa Dougl. ex Laws., forests, from 2004 to 2007 during low bark beetle populations. Residual stand BA ranged from 9.0 to 37.0 m2/ha. More predators and bark beetles were collected in passive traps in stands of lower BA than in stands of higher BA; however, significance varied by species and site, and total number of beetles collected was low. Height of the clear panel passive traps affected trap catches for some species at some sites and years. When pheromone lures were used with funnel traps [Ips pini (Say) lure: lanierone, +03/-97 ipsdienol], we found no significant difference in trap catches among basal area treatments for bark beetles and their predators. Similarly, when trees were baited (Dendroctonus brevicomis LeConte lure: myrcene, exo-brevicomin and frontalin), we found no significant difference for days to first bark beetle attack. Surveys of long-term thinning treatments found evidence of bark beetle attacks only in unthinned plots (approximately 37 m2/ha basal area). We discuss our results in terms of management implications for bark beetle trapping and control.

Comparison between periodic and stochastic parabolic light trapping structures for thin-film microcrystalline Silicon solar cells.

Science.gov (United States)

Peters, M; Battaglia, C; Forberich, K; Bläsi, B; Sahraei, N; Aberle, A G

2012-12-31

Light trapping is of very high importance for silicon photovoltaics (PV) and especially for thin-film silicon solar cells. In this paper we investigate and compare theoretically the light trapping properties of periodic and stochastic structures having similar geometrical features. The theoretical investigations are based on the actual surface geometry of a scattering structure, characterized by an atomic force microscope. This structure is used for light trapping in thin-film microcrystalline silicon solar cells. Very good agreement is found in a first comparison between simulation and experimental results. The geometrical parameters of the stochastic structure are varied and it is found that the light trapping mainly depends on the aspect ratio (length/height). Furthermore, the maximum possible light trapping with this kind of stochastic structure geometry is investigated. In a second step, the stochastic structure is analysed and typical geometrical features are extracted, which are then arranged in a periodic structure. Investigating the light trapping properties of the periodic structure, we find that it performs very similar to the stochastic structure, in agreement with reports in literature. From the obtained results we conclude that a potential advantage of periodic structures for PV applications will very likely not be found in the absorption enhancement in the solar cell material. However, uniformity and higher definition in production of these structures can lead to potential improvements concerning electrical characteristics and parasitic absorption, e.g. in a back reflector.

Extraordinary Light-Trapping Enhancement in Silicon Solar Cell Patterned with Graded Photonic Super-Crystals

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Safaa Hassan

2017-12-01

Full Text Available Light-trapping enhancement in newly discovered graded photonic super-crystals (GPSCs with dual periodicity and dual basis is herein explored for the first time. Broadband, wide-incident-angle, and polarization-independent light-trapping enhancement was achieved in silicon solar cells patterned with these GPSCs. These super-crystals were designed by multi-beam interference, rendering them flexible and efficient. The optical response of the patterned silicon solar cell retained Bloch-mode resonance; however, light absorption was greatly enhanced in broadband wavelengths due to the graded, complex unit super-cell nanostructures, leading to the overlap of Bloch-mode resonances. The broadband, wide-angle light coupling and trapping enhancement mechanism are understood to be due to the spatial variance of the index of refraction, and this spatial variance is due to the varying filling fraction, the dual basis, and the varying lattice constants in different directions.

Two new planthopper species (Hemiptera, Fulgoroidea, Caliscelidae) collected in pitfall traps in Zambia.

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Chmurova, Lucia; Webb, Michael D

2016-08-22

Two new species of planthoppers in the family Caliscelidae (Hemiptera: Fulgoroidea) are described from Zambia, i.e., Afronaso spinosa sp. n. and Calampocus zambiaensis sp. n. All specimens are flightless males and nearly all were collected from baited pitfall traps (except for one specimen collected from a yellow pan trap), suggesting that they live near to or on the ground.

Incorporating the Impacts of Small Scale Rock Heterogeneity into Models of Flow and Trapping in Target UK CO2 Storage Systems

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Jackson, S. J.; Reynolds, C.; Krevor, S. C.

2017-12-01

Predictions of the flow behaviour and storage capacity of CO2 in subsurface reservoirs are dependent on accurate modelling of multiphase flow and trapping. A number of studies have shown that small scale rock heterogeneities have a significant impact on CO2flow propagating to larger scales. The need to simulate flow in heterogeneous reservoir systems has led to the development of numerical upscaling techniques which are widely used in industry. Less well understood, however, is the best approach for incorporating laboratory characterisations of small scale heterogeneities into models. At small scales, heterogeneity in the capillary pressure characteristic function becomes significant. We present a digital rock workflow that combines core flood experiments with numerical simulations to characterise sub-core scale capillary pressure heterogeneities within rock cores from several target UK storage reservoirs - the Bunter, Captain and Ormskirk sandstone formations. Measured intrinsic properties (permeability, capillary pressure, relative permeability) and 3D saturations maps from steady-state core flood experiments were the primary inputs to construct a 3D digital rock model in CMG IMEX. We used vertical end-point scaling to iteratively update the voxel by voxel capillary pressure curves from the average MICP curve; with each iteration more closely predicting the experimental saturations and pressure drops. Once characterised, the digital rock cores were used to predict equivalent flow functions, such as relative permeability and residual trapping, across the range of flow conditions estimated to prevail in the CO2 storage reservoirs. In the case of the Captain sandstone, rock cores were characterised across an entire 100m vertical transect of the reservoir. This allowed analysis of the upscaled impact of small scale heterogeneity on flow and trapping. Figure 1 shows the varying degree to which heterogeneity impacted flow depending on the capillary number in the

Performance improvement of charge-trap memory by using a stacked Zr_0_._4_6Si_0_._5_4O_2/Al_2O_3 charge-trapping layer

International Nuclear Information System (INIS)

Tang, Zhenjie; Hu, Dan; Zhang, Xiwei; Zhao, Yage; Li, Rong

2016-01-01

The postdeposition annealing (PDA)-treated charge-trap flash memory capacitor with stacked Zr_0_._4_6Si_0_._5_4O_2/Al_2O_3 charge-trapping layer flanked by a SiO_2 tunneling oxide and an Al_2O_3 blocking oxide was fabricated and investigated. It is observed that the memory capacitor exhibits prominent memory characteristics with large memory windows 12.8 V in a ±10 V gate sweeping voltage range, faster program/erase speed, and good data-retention characteristics even at 125 C compared to a single charge-trapping layer (Zr_0_._4_6Si_0_._5_4O_2, Zr_0_._7_9Si_0_._2_1O_2, and Zr_0_._4_6Al_1_._0_8O_2_._5_4). The quantum wells and introduced interfacial traps of the stacked trapping layer regulate the storage and loss behavior of charges, and jointly contribute to the improved memory characteristics. Hence, the memory capacitor with a stacked trapping layer is a promising candidate in future nonvolatile charge-trap memory device design and application. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Rose-like I-doped Bi_2O_2CO_3 microspheres with enhanced visible light response: DFT calculation, synthesis and photocatalytic performance

International Nuclear Information System (INIS)

Zai, Jiantao; Cao, Fenglei; Liang, Na; Yu, Ke; Tian, Yuan; Sun, Huai; Qian, Xuefeng

2017-01-01

Highlights: • DFT reveals I"− can partially substitute CO_3"2"−to narrow the bandgap of Bi_2O_2CO_3. • Sodium citrate play a key role on the formation of rose-like I-doped Bi_2O_2CO_3. • Rose-like I-doped Bi_2O_2CO_3 show enhanced visible light response. • The catalyst has enhanced photocatalytic activity to organic and Cr(VI) pollutes. - Abstract: Based on the crystal structure and the DFT calculation of Bi_2O_2CO_3, I"− can partly replace the CO_3"2"−in Bi_2O_2CO_3 to narrow its bandgap and to enhance its visible light absorption. With this in mind, rose-like I-doped Bi_2O_2CO_3 microspheres were prepared via a hydrothermal process. This method can also be extended to synthesize rose-like Cl- or Br-doped Bi_2O_2CO_3 microspheres. Photoelectrochemical test supports the DFT calculation result that I- doping narrows the bandgap of Bi_2O_2CO_3 by forming two intermediate levels in its forbidden band. Further study reveals that I-doped Bi_2O_2CO_3 microspheres with optimized composition exhibit the best photocatalytic activity. Rhodamine B can be completely degraded within 6 min and about 90% of Cr(VI) can be reduced after 25 min under the irradiation of visible light (λ > 400 nm).

Benzalkonium Chloride Provides Remarkable Stability to Liquid Protein Lures for Trapping Anastrepha obliqua (Diptera: Tephritidae).

Science.gov (United States)

Lasa, R; Williams, T

2017-12-05

Hydrolyzed protein lures are widely used to monitor fruit fly pests but are rapidly degraded by microbial activity and must be replaced frequently. To improve the stability of lures, the quaternary ammonium biocide, benzalkonium chloride (BC), was evaluated in mixtures with two hydrolyzed proteins commonly used to monitor Anastrepha spp. The mean number of Anastrepha obliqua adults captured during six consecutive weeks using Captor + borax with the addition of 240 mg BC/liter, not renewed during the test, was similar to Captor + borax that was replaced at weekly intervals and was more effective than Captor + borax without BC. Numbers of A. obliqua flies captured in 30% CeraTrap diluted in water containing 240 mg BC/liter were similar to those caught in traps baited with Captor + borax or 30% CeraTrap without BC in the first 9 d of evaluation but was significantly more effective than both lures after 56 d. After >2 mo of use, 30% CeraTrap containing 240 mg BC/liter remained as effective as newly prepared 30% CeraTrap. The addition of BC to lures reduced surface tension of liquid lures by ~40-50%. However, when BC was increased to 720 mg BC/liter, only a small additional reduction in surface tension was observed and higher concentrations of BC did not increase capture rates. These findings could contribute to reduced costs for trapping networks and the development of long-lasting formulations of liquid protein lures for bait stations and mass-trapping targeted at major tephritid pests. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Factors influencing uptake of sylvatic plague vaccine baits by prairie dogs

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Abbott, Rachel C.; Russell, Robin E.; Richgels, Katherine; Tripp, Daniel W.; Matchett, Marc R.; Biggins, Dean E.; Rocke, Tonie E.

2017-01-01

Sylvatic plague vaccine (SPV) is a virally vectored bait-delivered vaccine expressing Yersinia pestis antigens that can protect prairie dogs (Cynomys spp.) from plague and has potential utility as a management tool. In a large-scale 3-year field trial, SPV-laden baits containing the biomarker rhodamine B (used to determine bait consumption) were distributed annually at a rate of approximately 100–125 baits/hectare along transects at 58 plots encompassing the geographic ranges of four species of prairie dogs. We assessed site- and individual-level factors related to bait uptake in prairie dogs to determine which were associated with bait uptake rates. Overall bait uptake for 7820 prairie dogs sampled was 70% (95% C.I. 69.9–72.0). Factors influencing bait uptake rates by prairie dogs varied by species, however, in general, heavier animals had greater bait uptake rates. Vegetation quality and day of baiting influenced this relationship for black-tailed, Gunnison’s, and Utah prairie dogs. For these species, baiting later in the season, when normalized difference vegetation indices (a measure of green vegetation density) are lower, improves bait uptake by smaller animals. Consideration of these factors can aid in the development of species-specific SPV baiting strategies that maximize bait uptake and subsequent immunization of prairie dogs against plague.

Conversion of CO2 via Visible Light Promoted Homogeneous Redox Catalysis

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Bernhard Rieger

2012-11-01

Full Text Available This review gives an overview on the principles of light-promoted homogeneous redox catalysis in terms of applications in CO2 conversion. Various chromophores and the advantages of different structures and metal centers as well as optimization strategies are discussed. All aspects of the reduction catalyst site are restricted to CO2 conversion. An important focus of this review is the question of a replacement of the sacrificial donor which is found in most of the current publications. Furthermore, electronic parameters of supramolecular systems are reviewed with reference to the requisite of chromophores, oxidation and reduction sites.

Spectral and directional dependence of light-trapping in solar cells

Energy Technology Data Exchange (ETDEWEB)

Ulbrich, Carolin

2011-02-17

This thesis investigates the directional and spectral dependence of light-incoupling and light-trapping in solar cells. The light-trapping does not notably change under increased angles of incidence. To enhance the incoupling at the front of the solar cell, the effects of a textured surface structure on the cover glass of the solar cell are investigated. The texture reduces the reflectance at the air-glass interface and, additionally, reduces the reflection losses originating at the interface between the glass and the transparent conductive oxide (TCO) as well as the TCO and the silicon (Si) absorber due to the randomization of light. On samples without a textured TCO/Si interface, the textured foil induces additional light-trapping in the photovoltaically active absorber material. This effect is not observed for samples with a textured TCO/Si interface. In this case, using tandem solar cells, a redistribution of light absorption in the top and bottom subcells is detected. The antireflective texture increases the short circuit current density in thin film silicon tandem solar cells by up to 1 mA/cm{sup 2}, and the conversion efficiency by up to 0.7 % absolute. The increase in the annual yield of solar cells is estimated to be up to 10 %. Further, the spectral dependence of the efficiency and annual yield of a tandem solar cell was investigated. The daily variation of the incident spectrum causes a change in the current matching of the serial connected subcells. Simulations determine the optimum subcell layer thicknesses of tandem solar cells. The thicknesses optimized in respect to the annual yield overlap in a wide range for both investigated locations with those for the AM1.5g standard spectrum. Though, a slight top limitation is favorable. Matching the short circuit currents of the subcells maximizes the overall current, but minimizes the fill factor. This thesis introduces a new definition for the matching condition of tandem solar cells. This definition

Hidrogenionic potential (pH of the attractant, trap density and control threshold for Ceratitis capitata (DIPTERA: TEPHRITIDAE on Hamlin oranges in São Paulo central region, Brazil

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Paulo Eduardo Branco Paiva

2013-06-01

Full Text Available This study evaluated the effect of initial pH values of 4.5, 6.5 and 8.5 of the attractant (protein bait Milhocina® and borax (sodium borate in the field, on the capture of fruit flies in McPhail traps, using 1, 2, 4 and 8 traps per hectare, in order to estimate control thresholds in a Hamlin orange grove in the central region of the state of São Paulo. The most abundant fruit fly species was Ceratitis capitata, comprising almost 99% of the fruit flies captured, of which 80% were females. The largest captures of C. capitata were found in traps baited with Milhocina® and borax at pH 8.5. Captures per trap for the four densities were similar, indicating that the population can be estimated with one trap per hectare in areas with high populations. It was found positive relationships between captures of C. capitata and the number of Hamlin oranges damaged, 2 and 3 weeks after capture. It was obtained equations that correlate captures and damage levels which can be used to estimate control thresholds. The average loss caused in Hamlin orange fruits by C. capitata was 2.5 tons per hectare or 7.5% of production.

Thermodynamic balance of photosynthesis and transpiration at increasing CO2 concentrations and rapid light fluctuations.

Science.gov (United States)

Marín, Dolores; Martín, Mercedes; Serrot, Patricia H; Sabater, Bartolomé

2014-02-01

Experimental and theoretical flux models have been developed to reveal the influence of sun flecks and increasing CO2 concentrations on the energy and entropy balances of the leaf. The rapid and wide range of fluctuations in light intensity under field conditions were simulated in a climatic gas exchange chamber and we determined the energy and entropy balance of the leaf based on radiation and gas exchange measurements. It was estimated that the energy of photosynthetic active radiation (PAR) accounts for half of transpiration, which is the main factor responsible for the exportation of the entropy generated in photosynthesis (Sg) out of the leaf in order to maintain functional the photosynthetic machinery. Although the response of net photosynthetic production to increasing concentrations of CO2 under fluctuating light is similar to that under continuous light, rates of transpiration respond slowly to changes of light intensity and are barely affected by the concentration of CO2 in the range of 260-495 ppm, in which net photosynthesis increases by more than 100%. The analysis of the results confirms that future increases of CO2 will improve the efficiency of the conversion of radiant energy into biomass, but will not reduce the contribution of plant transpiration to the leaf thermal balance. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

PAMAM templated N,Pt co-doped TiO2 for visible light photodegradation of brilliant black.

Science.gov (United States)

Nzaba, Sarre Kadia Myra; Ntsendwana, Bulelwa; Mamba, Bhekie Brilliance; Kuvarega, Alex Tawanda

2018-05-01

This study examined the photocatalytic degradation of an azo dye brilliant black (BB) using non-metal/metal co-doped TiO 2 . N,Pt co-doped TiO 2 photocatalysts were prepared by a modified sol-gel method using amine-terminated polyamidoamine dendrimer generation 0 (PG0) as a template and source of nitrogen. Structural, morphological, and textural properties were evaluated using scanning electron microscopy coupled to energy-dispersive X-ray spectroscopy (SEM/EDX), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR), Raman spectroscopy (RS), photoluminescence (PL) and ultra-violet/visible spectroscopy (UV-Vis). The synthesized photocatalysts exhibited lower band gap energies as compared to the Degussa P-25, revealing a red shift in band gap towards the visible light absorption region. Photocatalytic activity of N,Pt co-doped TiO 2 was measured by the reaction of photocatalytic degradation of BB dye. Enhanced photodegradation efficiency of BB was achieved after 180-min reaction time with an initial concentration of 50 ppm. This was attributed to the rod-like shape of the materials, larger surface area, and enhanced absorption of visible light induced by N,Pt co-doping. The N,Pt co-doped TiO 2 also exhibited pseudo-first-order kinetic behavior with half-life and rate constant of 0.37 and 0.01984 min -1 , respectively. The mechanism of the photodegradation of BB under the visible light irradiation was proposed. The obtained results prove that co-doping of TiO 2 with N and Pt contributed to the enhanced photocatalytic performances of TiO 2 for visible light-induced photodegradation of organic contaminants for environmental remediation. Therefore, this work provides a new approach to the synthesis of PAMAM templated N,Pt co-doped TiO 2 for visible light photodegradation of brilliant black.

Non-sensitized selective photochemical reduction of CO2 to CO under visible light with an iron molecular catalyst.

Science.gov (United States)

Rao, Heng; Bonin, Julien; Robert, Marc

2017-03-02

A substituted tetraphenyl iron porphyrin, bearing positively charged trimethylammonio groups at the para position of each phenyl ring, demonstrates its ability as a homogeneous molecular catalyst to selectively reduce CO 2 to CO under visible light irradiation in organic media without the assistance of a sensitizer and no competitive hydrogen evolution for several days.

Amblyomma tapirellum  (Acari: Ixodidae collected from tropical forest canopy [v2; ref status: indexed, http://f1000r.es/2uy

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Jose R Loaiza

2014-01-01

Full Text Available Free-ranging ticks are widely known to be restricted to the ground level of vegetation. Here, we document the capture of the tick species Amblyomma tapirellum in light traps placed in the forest canopy of Barro Colorado Island, central Panama. A total of forty eight adults and three nymphs were removed from carbon dioxide–octenol baited CDC light traps suspended 20 meters above the ground during surveys for forest canopy mosquitoes. To our knowledge, this represents the first report of questing ticks from the canopy of tropical forests. Our finding suggests a novel ecological relationship between A. tapirellum and arboreal mammals, perhaps monkeys that come to the ground to drink or to feed on fallen fruits.

Initial pen and field assessment of baits to use in oral rabies vaccination of Formosan ferret-badgers in response to the re-emergence of rabies in Taiwan.

Science.gov (United States)

Wallace, Ryan M; Lai, Yuching; Doty, Jeffrey B; Chen, Chen-Chih; Vora, Neil M; Blanton, Jesse D; Chang, Susan S; Cleaton, Julie M; Pei, Kurtis J C

2018-01-01

Taiwan had been considered rabies free since 1961, until a newly established wildlife disease surveillance program identified rabies virus transmission within the Formosan ferret-badger (Melogale moschata subaurantiaca) in 2013. Ferret-badgers occur throughout southern China and Southeast Asia, but their ecological niche is not well described. As an initial feasibility assessment for potential rabies control measures, field camera trapping and pen assessment of 6 oral rabies vaccine (ORV) baits were conducted in Taiwan in 2013. 46 camera nights were recorded; 6 Formosan ferret-badgers and 14 non-target mammals were sighted. No baits were consumed by ferret-badgers and 8 were consumed by non-target mammals. Penned ferret-badgers ingested 5 of the 18 offered baits. When pen and field trials were combined, and analyzed for palatability, ferret-badgers consumed 1 of 9 marshmallow baits (11.1%), 1 of 21 fishmeal baits (4.8%), 0 of 3 liver baits, and 3 of 3 fruit-flavored baits. It took an average of 261 minutes before ferret-badgers made oral contact with the non-fruit flavored baits, and 34 minutes for first contact with the fruit-based bait. Overall, ferret-badgers sought out the fruit baits 8 times faster, spent a greater proportion of time eating fruit baits, and were 7.5 times more likely to have ruptured the vaccine container of the fruit-based bait. Ferret-badgers are now recognized as rabies reservoir species in China and Taiwan, through two independent 'dog to ferret-badger' host-shift events. Species of ferret-badgers can be found throughout Indochina, where they may be an unrecognized rabies reservoir. Findings from this initial study underscore the need for further captive and field investigations of fruit-based attractants or baits developed for small meso-carnivores. Non-target mammals' competition for baits, ants, bait design, and dense tropical landscape represent potential challenges to effective ORV programs that will need to be considered in future

Initial pen and field assessment of baits to use in oral rabies vaccination of Formosan ferret-badgers in response to the re-emergence of rabies in Taiwan.

Directory of Open Access Journals (Sweden)

Ryan M Wallace

Full Text Available Taiwan had been considered rabies free since 1961, until a newly established wildlife disease surveillance program identified rabies virus transmission within the Formosan ferret-badger (Melogale moschata subaurantiaca in 2013. Ferret-badgers occur throughout southern China and Southeast Asia, but their ecological niche is not well described.As an initial feasibility assessment for potential rabies control measures, field camera trapping and pen assessment of 6 oral rabies vaccine (ORV baits were conducted in Taiwan in 2013. 46 camera nights were recorded; 6 Formosan ferret-badgers and 14 non-target mammals were sighted. No baits were consumed by ferret-badgers and 8 were consumed by non-target mammals. Penned ferret-badgers ingested 5 of the 18 offered baits. When pen and field trials were combined, and analyzed for palatability, ferret-badgers consumed 1 of 9 marshmallow baits (11.1%, 1 of 21 fishmeal baits (4.8%, 0 of 3 liver baits, and 3 of 3 fruit-flavored baits. It took an average of 261 minutes before ferret-badgers made oral contact with the non-fruit flavored baits, and 34 minutes for first contact with the fruit-based bait. Overall, ferret-badgers sought out the fruit baits 8 times faster, spent a greater proportion of time eating fruit baits, and were 7.5 times more likely to have ruptured the vaccine container of the fruit-based bait.Ferret-badgers are now recognized as rabies reservoir species in China and Taiwan, through two independent 'dog to ferret-badger' host-shift events. Species of ferret-badgers can be found throughout Indochina, where they may be an unrecognized rabies reservoir. Findings from this initial study underscore the need for further captive and field investigations of fruit-based attractants or baits developed for small meso-carnivores. Non-target mammals' competition for baits, ants, bait design, and dense tropical landscape represent potential challenges to effective ORV programs that will need to be

Initial pen and field assessment of baits to use in oral rabies vaccination of Formosan ferret-badgers in response to the re-emergence of rabies in Taiwan

Science.gov (United States)

Wallace, Ryan M.; Lai, Yuching; Doty, Jeffrey B.; Chen, Chen-Chih; Vora, Neil M.; Blanton, Jesse D.; Chang, Susan S.; Pei, Kurtis J. C.

2018-01-01

Background Taiwan had been considered rabies free since 1961, until a newly established wildlife disease surveillance program identified rabies virus transmission within the Formosan ferret-badger (Melogale moschata subaurantiaca) in 2013. Ferret-badgers occur throughout southern China and Southeast Asia, but their ecological niche is not well described. Methodology/Principle findings As an initial feasibility assessment for potential rabies control measures, field camera trapping and pen assessment of 6 oral rabies vaccine (ORV) baits were conducted in Taiwan in 2013. 46 camera nights were recorded; 6 Formosan ferret-badgers and 14 non-target mammals were sighted. No baits were consumed by ferret-badgers and 8 were consumed by non-target mammals. Penned ferret-badgers ingested 5 of the 18 offered baits. When pen and field trials were combined, and analyzed for palatability, ferret-badgers consumed 1 of 9 marshmallow baits (11.1%), 1 of 21 fishmeal baits (4.8%), 0 of 3 liver baits, and 3 of 3 fruit-flavored baits. It took an average of 261 minutes before ferret-badgers made oral contact with the non-fruit flavored baits, and 34 minutes for first contact with the fruit-based bait. Overall, ferret-badgers sought out the fruit baits 8 times faster, spent a greater proportion of time eating fruit baits, and were 7.5 times more likely to have ruptured the vaccine container of the fruit-based bait. Conclusions/Significance Ferret-badgers are now recognized as rabies reservoir species in China and Taiwan, through two independent ‘dog to ferret-badger’ host-shift events. Species of ferret-badgers can be found throughout Indochina, where they may be an unrecognized rabies reservoir. Findings from this initial study underscore the need for further captive and field investigations of fruit-based attractants or baits developed for small meso-carnivores. Non-target mammals’ competition for baits, ants, bait design, and dense tropical landscape represent potential

Evaluation of imidacloprid-treated traps as an attract and kill system for filth flies during contingency operations.

Science.gov (United States)

Field trials were conducted to evaluate if filth fly trap efficacy was increased by application of an insecticide to a trap’s exterior. Four Fly Terminator® Pro traps baited with Fly Terminator® attractant were suspended on PVC pipe framing at a Florida waste transfer site. Exterior surfaces of tw...

Performance analysis of photocatalytic CO2 reduction in optical fiber monolith reactor with multiple inverse lights

International Nuclear Information System (INIS)

Yuan, Kai; Yang, Lijun; Du, Xiaoze; Yang, Yongping

2014-01-01

Highlights: • A new optical fiber monolith reactor model for CO 2 reduction was developed. • Methanol concentration versus fiber location and operation parameters was obtained. • Reaction efficiency increases by 31.1% due to the four fibers and inverse layout. • With increasing space of fiber and channel center, methanol concentration increases. • Methanol concentration increases as the vapor ratio and light intensity increase. - Abstract: Photocatalytic CO 2 reduction seems potential to mitigate greenhouse gas emissions and produce renewable energy. A new model of photocatalytic CO 2 reduction in optical fiber monolith reactor with multiple inverse lights was developed in this study to improve the conversion of CO 2 to CH 3 OH. The new light distribution equation was derived, by which the light distribution was modeled and analyzed. The variations of CH 3 OH concentration with the fiber location and operation parameters were obtained by means of numerical simulation. The results show that the outlet CH 3 OH concentration is 31.1% higher than the previous model, which is attributed to the four fibers and inverse layout. With the increase of the distance between the fiber and the monolith center, the average CH 3 OH concentration increases. The average CH 3 OH concentration also rises as the light input and water vapor percentage increase, but declines with increasing the inlet velocity. The maximum conversion rate and quantum efficiency in the model are 0.235 μmol g −1 h −1 and 0.0177% respectively, both higher than previous internally illuminated monolith reactor (0.16 μmol g −1 h −1 and 0.012%). The optical fiber monolith reactor layout with multiple inverse lights is recommended in the design of photocatalytic reactor of CO 2 reduction

Short- and long-term control of Vespula pensylvanica in Hawaii by fipronil baiting

Science.gov (United States)

Hanna, Cause; Foote, David; Kremen, Claire

2012-01-01

BACKGROUND: The invasive western yellowjacket wasp, Vespula pensylvanica (Saussure), has significantly impacted the ecological integrity and human welfare of Hawaii. The goals of the present study were (1) to evaluate the immediate and long-term efficacy of a 0.1% fipronil chicken bait on V. pensylvanica populations in Hawaii Volcanoes National Park, (2) to quantify gains in efficacy using the attractant heptyl butyrate in the bait stations and (3) to measure the benefits of this approach for minimizing non-target impacts to other arthropods. RESULTS: The 0.1% fipronil chicken bait reduced the abundance of V. pensylvanica by 95 ± 1.2% during the 3 months following treatment and maintained a population reduction of 60.9 ± 3.1% a year after treatment in the fipronil-treated sites when compared with chicken-only sites. The addition of heptyl butyrate to the bait stations significantly increased V. pensylvanica forager visitation and bait take and significantly reduced the non-target impacts of fipronil baiting. CONCLUSION: In this study, 0.1% fipronil chicken bait with the addition of heptyl butyrate was found to be an extremely effective large-scale management strategy and provided the first evidence of a wasp suppression program impacting Vepsula populations a year after treatment. Copyright © 2011 Society of Chemical Industry

Growth of nicotiana in response to atmospheric CO sub 2 enrichment and various light regimes

Energy Technology Data Exchange (ETDEWEB)

Pope, S.; Thomas, J.F. (North Carolina State Univ., Raleigh (USA))

1989-04-01

Nicotiana tabacum NCTG-22, N. tabacum Petite Havana and N. plumbaginifolia were grown in chambers (24 C, 12-h light) under daytime atmospheric CO{sub 2} levels of 340 ppm (ambient) or 1000 ppm (enriched). All 3 types of tobacco grew faster and had open flowers sooner under CO2 enrichment, but patterns of dry weight distribution varied with type of tobacco. In N. plumbaginifolia significant proportions of dry weight were allocated to stems and branches, while in tabacum types, less was allocated to stems and more to leaves and roots. Increases in dry weight due to CO2 enrichment were accompanied by increases in leaf area and thickness. Plants given a far-red low intensity night break exhibited few differences from controls except having thinner leaves under ambient CO2; but under enriched CO2, had greater total dry weight and thicker leaves containing a higher proportion of spongy mesophyll than controls. A 50% reduction in light intensity led to a comparable reduction in dry weight and leaf area across treatments.

Efficacy of locally produced papain enzyme for the production of protein bait for bactrocera invadens (diptera: tephritidae) control in Ghana

International Nuclear Information System (INIS)

Aggrey-Korsah, R.

2014-07-01

Autolysed brewery yeast waste is currently being used as cost effective protein bait for Bactrocera invadens control the world over to replace commercial protein hydrolysate bait formulations. However, significant reduction in production cost can be achieved when all the production materials are from local sources. This experiment was aimed at assessing the efficacy of locally produced papain extracted from 'Red lady' pawpaw fruit latex and skin peel to be used for protein bait production. Aqueous two-phase extraction of papain from pawpaw fruit latex with 15 % (NH 4 ) 2 SO 4 - 8 % PEG recovered 64.72 ± 2.08 % papain into the supernatant with 7.33 % proteolytic activity yield and a fold purification of 58.11 ± 1.67. Proteolytic activity and protein concentration measured for the aqueous two-phase extracts of pawpaw skin peel were significantly higher (p= 0.00) than crude extracts of skin peel. However, the aqueous two phase extraction of papain from skin peel needs to be optimised further since SDS-PAGE showed no visible bands in the different phase extracts. Gamma irradiation at 10 KGy increased the proteolytic activity of crude papain by 21.69 % of the non-irradiated papain and subsequently increased the specific activity by 18.51 % but the protein concentration was not affected. Protein baits prepared with crude papain extracted from the pawpaw fruit latex and skin peels were evaluated in laboratory bioassays with wild flies reared from field collected infested mangoes. The source of papain did not affect the protein bait recovery, the pH and protein concentration though colour of bait differed for crude fruit latex papain bait (dark brown) and skin peel papain bait (light brown). The bait preparations had equal attractance to male and female B. invadens. Mean attractance to protein baits produced with fruit latex and skin peel papain baits were between 25.00 ± 7.56 % and 47.50 ± 11.09 % respectively for males, 25.00 ± 13.13 % and 32.86 ± 8

Rising CO2 interacts with growth light and growth rate to alter photosystem II photoinactivation of the coastal diatom Thalassiosira pseudonana.

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Gang Li

Full Text Available We studied the interactive effects of pCO(2 and growth light on the coastal marine diatom Thalassiosira pseudonana CCMP 1335 growing under ambient and expected end-of-the-century pCO(2 (750 ppmv, and a range of growth light from 30 to 380 µmol photons·m(-2·s(-1. Elevated pCO(2 significantly stimulated the growth of T. pseudonana under sub-saturating growth light, but not under saturating to super-saturating growth light. Under ambient pCO(2 susceptibility to photoinactivation of photosystem II (σ(i increased with increasing growth rate, but cells growing under elevated pCO(2 showed no dependence between growth rate and σ(i, so under high growth light cells under elevated pCO(2 were less susceptible to photoinactivation of photosystem II, and thus incurred a lower running cost to maintain photosystem II function. Growth light altered the contents of RbcL (RUBISCO and PsaC (PSI protein subunits, and the ratios among the subunits, but there were only limited effects on these and other protein pools between cells grown under ambient and elevated pCO(2.

16 CFR 238.1 - Bait advertisement.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Bait advertisement. 238.1 Section 238.1 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES AGAINST BAIT ADVERTISING... when the offer is not a bona fide effort to sell the advertised product. [Guide 1] ...

Trap attributes influencing capture of Diabrotica speciosa (Coleoptera: Chrysomelidae on common bean fields Atributos da armadilha influenciam captura de Diabrotica speciosa (Coleoptera: Chrysomelidae em feijoeiro

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Maurício Ursi Ventura

2005-08-01

Full Text Available Refinements in trap characteristics may improve ability to monitor and mass-trap beetles. Field assays were conducted in common bean fields to assess responses of Diabrotica speciosa (Germar to some trap characteristics. Golden yellow plastic cups (750 mL traps caught more D. speciosa females and males than did clear traps. Carrot slices in Petri dishes baited with Lagenaria vulagaris L. powder (cucurbitacin source - 0.28% caught more beetles than did dishes with carrot alone. Dispensers for the floral volatile attractant 1,4-dimethoxybenze were also compared. Rubber septa dispenser attracted more beetles than did control (dental wicks saturated with acetone. Captures on dental wick, starch matrix and feminine pad dispensers were intermediate and did not differ from those on rubber septa and unbaited controls. Perforated bottle traps (2000 mL, when baited with the floral attractant, caught more beetles than did window bottle traps (both traps contained L. vulgaris powder in most assessments done from two to ten days after trap placement in the field. Traps with the insecticide carbaryl captured more beetles than did traps without it, 2-4 and 8-10 days after trap placement in the field, but not in the remaining periods (0-2, 4-6 and 6-8 days. Traps baited with 1,4-dimethoxybenzene captured more beetles than did the unbaited ones in all assessments (each other day from two to ten days after trap placement in the field. Finally, similar amounts of beetles were captured using plastic bottle traps (2000 mL: perforated, window (both with cucurbitacin and sticky (without cucurbitacin traps, when were baited with the floral attractant.Refinamentos em caraterísticas de armadilhas podem incrementar sua habilidade para monitorar e capturar em massa os insetos. Experimentos foram conduzidos em lavoura de feijoeiro para verificar as respostas de Diabrotica speciosa (Germar a algumas características de armadilhas. Armadilhas de copos plástico (750 m

Light trapping and circularly polarization at a Dirac point in 2D plasma photonic crystals

Science.gov (United States)

Li, Qian; Hu, Lei; Mao, Qiuping; Jiang, Haiming; Hu, Zhijia; Xie, Kang; Wei, Zhang

2018-03-01

Light trapping at the Dirac point in 2D plasma photonic crystal has been obtained. The new localized mode, Dirac mode, is attributable to neither photonic bandgap nor total internal reflection. It exhibits a unique algebraic profile and possesses a high-Q factor resonator of about 105. The Dirac point could be modulated by tuning the filling factor, plasma frequency and plasma cyclotron frequency, respectively. When a magnetic field parallel to the wave vector is applied, Dirac modes for right circularly polarized and left circularly polarized waves could be obtained at different frequencies, and the Q factor could be tuned. This property will add more controllability and flexibility to the design and modulation of novel photonic devices. It is also valuable for the possibilities of Dirac modes in photonic crystal containing other kinds of metamaterials.

Efficacy of commercial baits and new active ingredients against firebrats and silverfish (Zygentoma: Lepismatidae).

Science.gov (United States)

Sims, Steven R; Appel, Arthur G

2012-08-01

Commercial baits containing boric acid, hydramethynon, and indoxacarb were tested against the firebrat, Thermobia domestica (Packard), and silverfish, Lepisma saccharina L. (both Zygentoma: Lepismatidae), under laboratory conditions. Three boric acid baits were consumed in significantly smaller amounts than untreated control food and did not effectively control either species. Baits containing hydramethylnon and indoxacarb were consumed in greater amounts than boric acid baits, but were relatively ineffective, with LT50 values >9 d. Presence or absence of competitive untreated food did not consistently affect bait efficacy. A ground oat matrix was used to evaluate the potential effectiveness of abamectin, chlorfenapyr, dinotefuran, fipronil, hydramethylnon, metaflumizone, and novaluron baits. The most effective compound was chlorfenapyr. At 0.05 and 0.20% (wt:wt) rates, chlorfenapyr baits produced LT50 values, for both species, ranging from 2 to 4 d. All other compounds had LT50 values >7 d.

An Integrated Response of Trichodesmium erythraeum IMS101 Growth and Photo-Physiology to Iron, CO2, and Light Intensity.

Science.gov (United States)

Boatman, Tobias G; Oxborough, Kevin; Gledhill, Martha; Lawson, Tracy; Geider, Richard J

2018-01-01

We have assessed how varying CO 2 (180, 380, and 720 μatm) and growth light intensity (40 and 400 μmol photons m -2 s -1 ) affected Trichodesmium erythraeum IMS101 growth and photophysiology over free iron (Fe') concentrations between 20 and 9,600 pM. We found significant iron dependencies of growth rate and the initial slope and maximal relative PSII electron transport rates (rP m ). Under iron-limiting concentrations, high-light increased growth rates and rP m ; possibly indicating a lower allocation of resources to iron-containing photosynthetic proteins. Higher CO 2 increased growth rates across all iron concentrations, enabled growth to occur at lower Fe' concentrations, increased rP m and lowered the iron half saturation constants for growth (K m ). We attribute these CO 2 responses to the operation of the CCM and the ATP spent/saved for CO 2 uptake and transport at low and high CO 2 , respectively. It seems reasonable to conclude that T. erythraeum IMS101 can exhibit a high degree of phenotypic plasticity in response to CO 2 , light intensity and iron-limitation. These results are important given predictions of increased dissolved CO 2 and water column stratification (i.e., higher light exposures) over the coming decades.

An Integrated Response of Trichodesmium erythraeum IMS101 Growth and Photo-Physiology to Iron, CO2, and Light Intensity

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Tobias G. Boatman

2018-04-01

Full Text Available We have assessed how varying CO2 (180, 380, and 720 μatm and growth light intensity (40 and 400 μmol photons m−2 s−1 affected Trichodesmium erythraeum IMS101 growth and photophysiology over free iron (Fe′ concentrations between 20 and 9,600 pM. We found significant iron dependencies of growth rate and the initial slope and maximal relative PSII electron transport rates (rPm. Under iron-limiting concentrations, high-light increased growth rates and rPm; possibly indicating a lower allocation of resources to iron-containing photosynthetic proteins. Higher CO2 increased growth rates across all iron concentrations, enabled growth to occur at lower Fe′ concentrations, increased rPm and lowered the iron half saturation constants for growth (Km. We attribute these CO2 responses to the operation of the CCM and the ATP spent/saved for CO2 uptake and transport at low and high CO2, respectively. It seems reasonable to conclude that T. erythraeum IMS101 can exhibit a high degree of phenotypic plasticity in response to CO2, light intensity and iron-limitation. These results are important given predictions of increased dissolved CO2 and water column stratification (i.e., higher light exposures over the coming decades.

Odour-baited targets to control New World screwworm: A preliminary field study in Mexico

International Nuclear Information System (INIS)

Torr, S.J.; Hall, M.J.R.

1992-01-01

Biconical, F3 and Wind Oriented (WOT) traps and black cloth targets, baited with swormlure-4, were assessed as catching and killing devices for the New World screwworm fly, Cochliomyia hominivorax, in Mexico. The WOT was significantly better than the other trap designs, with a mean catch 2.7 and 86.4 times better than those of the Biconical and F3, respectively. It was demonstrated that the release of swormlure-4 could be reduced from the standard 10 ml/day to 2 ml/day without a reduction in the numbers of screwworm caught in a WOT. Use of electric nets demonstrated that a visual target was not necessary for the precise location of a swormlure-4 source by screwworm. Target colour was important with respect to the landing response of screwworms on targets: in a two-choice situation, flies landed much more frequently on black than on blue or yellow, and more on these two colours than they did on white. Screwworm tend not to circle a target before landing on it: about 75% of the flies caught on a combination of electrified black target plus electric flanking net were caught on the target. 6 tabs

Facile synthesis of surface N-doped Bi_2O_2CO_3: Origin of visible light photocatalytic activity and in situ DRIFTS studies

International Nuclear Information System (INIS)

Zhou, Ying; Zhao, Ziyan; Wang, Fang; Cao, Kun; Doronkin, Dmitry E.; Dong, Fan; Grunwaldt, Jan-Dierk

2016-01-01

Graphical abstract: Surfactant (CTAB) can induce nitrogen interstitially doping in the Bi_2O_2CO_3 surface, leading to the formation of localized states from N−O bond, which probably account for the origin of the visible light activity. Moreover, the photocatalytic NO oxidation processes over Bi_2O_2CO_3 were successfully monitored for the first time by in situ DRIFTS. - Highlights: • Interstitially doping N in the Bi_2O_2CO_3 surface was achieved at room temperature. • N-doped Bi_2O_2CO_3 exhibited significantly enhanced visible light photocatalytic activity compared to the pristine Bi_2O_2CO_3. • The formation of localized states from N−O bond could account for the visible light activity of Bi_2O_2CO_3. • The photocatalytic NO oxidation process was monitored by in situ DRIFTS. - Abstract: Bi_2O_2CO_3 nanosheets with exposed {001} facets were prepared by a facile room temperature chemical method. Due to the high oxygen atom density in {001} facets of Bi_2O_2CO_3, the addition of cetyltrimethylammonium bromide (CTAB) does not only influence the growth of crystalline Bi_2O_2CO_3, but also modifies the surface properties of Bi_2O_2CO_3 through the interaction between CTAB and Bi_2O_2CO_3. Nitrogen from CTAB as dopant interstitially incorporates in the Bi_2O_2CO_3 surface evidenced by both experimental and theoretical investigations. Hence, the formation of localized states from N−O bond improves the visible light absorption and charge separation efficiency, which leads to an enhancement of visible light photocatalytic activity toward to the degradation of Rhodamine B (RhB) and oxidation of NO. In addition, the photocatalytic NO oxidation over Bi_2O_2CO_3 nanosheets was successfully monitored for the first time using in situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS). Both bidentate and monodentate nitrates were identified on the surface of catalysts during the photocatalytic reaction process. The application of this strategy to

Light trapping in thin film solar cells using photonic engineering device concepts

Science.gov (United States)

Mutitu, James Gichuhi

In this era of uncertainty concerning future energy solutions, strong reservations have arisen over the continued use and pursuit of fossil fuels and other conventional sources of energy. Moreover, there is currently a strong and global push for the implementation of stringent measures, in order to reduce the amount of green house gases emitted by every nation. As a consequence, there has emerged a sudden and frantic rush for new renewable energy solutions. In this world of renewable energy technologies is where we find photovoltaic (PV) technology today. However, as is, there are still many issues that need to be addressed before solar energy technologies become economically viable and available to all people, in every part of the world. This renewed interest in the development of solar electricity, has led to the advancement of new avenues that address the issues of cost and efficiency associated with PV. To this end, one of the prominent approaches being explored is thin film solar cell (TFSC) technology, which offers prospects of lower material costs and enables larger units of manufacture than conventional wafer based technology. However, TFSC technologies suffer from one major problem; they have lower efficiencies than conventional wafer based solar cell technologies. This lesser efficiency is based on a number of reasons, one of which is that with less material, there is less volume for the absorption of incident photons. This shortcoming leads to the need for optical light trapping; which is concerned with admitting the maximum amount of light into the solar cell and keeping the light within the structure for as long as possible. In this thesis, I present the fundamental scientific ideas, practice and methodology behind the application of photonic engineering device concepts to increase the light trapping capacity of thin film solar cells. In the introductory chapters, I develop the basic ideas behind light trapping in a sequential manner, where the effects

Visible light photocatalysts (Fe, N):TiO{sub 2} from ammonothermally processed, solvothermal self-assembly derived Fe-TiO{sub 2} mesoporous microspheres

Energy Technology Data Exchange (ETDEWEB)

Zou, Mingming; Xiong, Fengqiang; Ganeshraja, Ayyakannu Sundaram [Dalian Institute of Chemical Physics (DICP), Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning, 116023 (China); Feng, Xiaohua; Wang, Chuanxi [Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201 (China); Thomas, Tiju, E-mail: tijuthomas@iitm.ac.in [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai, 600036, Tamil Nadu (India); Yang, Minghui, E-mail: myang@dicp.ac.cn [Dalian Institute of Chemical Physics (DICP), Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning, 116023 (China)

2017-07-01

Iron (III) and nitrogen co-doped mesoporous TiO{sub 2} microspheres (Fe-N-TiO{sub 2}) are prepared using a self-assembly based solvothermal process followed by an ammonothermal method. Among all samples, 1 mol.% of Fe dopants and 500 °C nitridation (for 2 h) gives the highest visible light photoactivity. Results imply that the Fe{sup 3+}/Fe{sup 2+} dopant trap energy level introduced within the band gap in mildly Fe (∼1 at%) doped TiO{sub 2} and the mesoporous nature of the material, both aid in the observed catalytic performance. Subjecting Fe-TiO{sub 2} samples to ammonothermal process induces oxygen vancancies, and substitutional and interstitial N. This reduces optical band gap, and introduces local states. The lower band gap and local states together aid in the absorption of visible light and separation of charge carriers. Co-dopants are distributed uniformly in the best photocatalysts. The active species generated in the photocatalytic system is shown to be singlet molecular oxygen ({sup 1}O{sub 2}) using selective radical quenchers. - Highlights: • Iron (III) and nitrogen co-doped mesoporous TiO{sub 2} microspheres (Fe-N-TiO{sub 2}) are prepared. • Fe{sup 3+}/Fe{sup 2+} dopant trap energy level introduced within the band gap in Fe (∼1 at%) doped TiO{sub 2}. • Subjecting Fe-TiO{sub 2} samples to ammonothermal process induces oxygen vancancies, and causes substitutional and interstitial N. • Co-dopants are distributed uniformly in the best photocatalysts. • Active species generated is shown to be singlet molecular oxygen ({sup 1}O{sub 2}).

The trap states in lightly Mg-doped GaN grown by MOVPE on a freestanding GaN substrate

Science.gov (United States)

Narita, Tetsuo; Tokuda, Yutaka; Kogiso, Tatsuya; Tomita, Kazuyoshi; Kachi, Tetsu

2018-04-01

We investigated traps in lightly Mg-doped (2 × 1017 cm-3) p-GaN fabricated by metalorganic vapor phase epitaxy (MOVPE) on a freestanding GaN substrate and the subsequent post-growth annealing, using deep level transient spectroscopy. We identified four hole traps with energy levels of EV + 0.46, 0.88, 1.0, and 1.3 eV and one electron trap at EC - 0.57 eV in a p-type GaN layer uniformly doped with magnesium (Mg). The Arrhenius plot of hole traps with the highest concentration (˜3 × 1016 cm-3) located at EV + 0.88 eV corresponded to those of hole traps ascribed to carbon on nitrogen sites in n-type GaN samples grown by MOVPE. In fact, the range of the hole trap concentrations at EV + 0.88 eV was close to the carbon concentration detected by secondary ion mass spectroscopy. Moreover, the electron trap at EC - 0.57 eV was also identical to the dominant electron traps commonly observed in n-type GaN. Together, these results suggest that the trap states in the lightly Mg-doped GaN grown by MOVPE show a strong similarity to those in n-type GaN, which can be explained by the Fermi level close to the conduction band minimum in pristine MOVPE grown samples due to existing residual donors and Mg-hydrogen complexes.

Natural infection of Culex theileri (Diptera: Culicidae) with Dirofilaria immitis (Nematoda: Filarioidea) on Madeira Island, Portugal.

Science.gov (United States)

Santa-Ana, Marta; Khadem, Manhaz; Capela, Ruben

2006-01-01

Field and laboratory studies were performed to verify whether Culex theileri Theobald functions as a natural vector of Dirofilaria immitis (Leidy) on Madeira Island, Portugal. CO2-baited light traps (EVS traps) were use to sample mosquitoes monthly basis between February 2002 and February 2003 in the area of Quebradas (Funchal). Three mosquito species were captured, including 58 Culex pipiens L., 790 Cx. theileri, and three Culiseta longiareolata (Macquart). Only C. theileri tested positive for D. immitis. The presence of this filarial worm was detected by direct observation, infectivity assay dissection technique, and polymerase chain reaction methods. Infected mosquitoes were recovered in October and December 2002 and January 2003. These data provide evidence that Cx. theileri could be the main vector of D. immitis in Funchal, Madeira.

Well-crystallized ZnCo{sub 2}O{sub 4} nanosheets as a new-style support of Au catalyst for high efficient CO preferential oxidation in H{sub 2} stream under visible light irradiation

Energy Technology Data Exchange (ETDEWEB)

Yang, Kai [Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350002 (China); School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi (China); Zhang, Yujuan; Meng, Chao [Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350002 (China); Cao, FangFang [School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi (China); State Key Laboratory of Advanced Technology for Float Glass Technology, Bengbu 233000 (China); Chen, Xun; Fu, Xianzhi [Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350002 (China); Dai, Wenxin, E-mail: daiwenxin@fzu.edu.cn [Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350002 (China); Yu, Changlin, E-mail: yuchanglinjx@163.com [School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, Jiangxi (China)

2017-01-01

Highlights: • Spinel ZnCo{sub 2}O{sub 4} nanosheets were fabricated by a facile template-free wet chemical method. • ZnCo{sub 2}O{sub 4} nanosheet supported Au catalyst exhibited a good stability for oxidizing CO. • Visible light could promote the adsorption and activation of CO and O{sub 2} on Au/ZnCo{sub 2}O{sub 4}. • A efficient charge transfer occurred on the interface of Au and ZnCo{sub 2}O{sub 4}. - Abstract: A kind of high dispersed gold catalyst supported on the spinel ZnCo{sub 2}O{sub 4} nanosheets was readily fabricated by a facile template-free wet chemical method for CO oxidation in H{sub 2}-rich streams at room temperature under visible light irradiation or not, which was found to be a high performance catalyst. As verified by X-ray powder diffractometry (XRD), Raman spectra, N{sub 2} adsorption–desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscope (XPS), photoelectrochemical measurement and photoluminescence (PL) spectra results, the contribution of high crystallinity, the enhanced mass and charge transport, the longer lifetime of surface electrons as well as the optical absorbance properties on Au/ZnCo{sub 2}O{sub 4} enabled the superior CO preferential oxidation. Notably, electron paramagnetic resonance (EPR) and CO chemisorption (TPD-MS) results indicate that visible light could promote the adsorption and activation of both CO and O{sub 2} at Au/ZnCo{sub 2}O{sub 4} due to both the photo-response of Au nanoparticles and the photo-excitation of ZnCo{sub 2}O{sub 4} band gap under visible light irradiation. This study indicates that Au/ZnCo{sub 2}O{sub 4} may be highly desirable for a promising photo-assisted Au catalyst.

Modeling CO2-Water-Mineral Wettability and Mineralization for Carbon Geosequestration.

Science.gov (United States)

Liang, Yunfeng; Tsuji, Shinya; Jia, Jihui; Tsuji, Takeshi; Matsuoka, Toshifumi

2017-07-18

Carbon dioxide (CO 2 ) capture and storage (CCS) is an important climate change mitigation option along with improved energy efficiency, renewable energy, and nuclear energy. CO 2 geosequestration, that is, to store CO 2 under the subsurface of Earth, is feasible because the world's sedimentary basins have high capacity and are often located in the same region of the world as emission sources. How CO 2 interacts with the connate water and minerals is the focus of this Account. There are four trapping mechanisms that keep CO 2 in the pores of subsurface rocks: (1) structural trapping, (2) residual trapping, (3) dissolution trapping, and (4) mineral trapping. The first two are dominated by capillary action, where wettability controls CO 2 and water two-phase flow in porous media. We review state-of-the-art studies on CO 2 /water/mineral wettability, which was found to depend on pressure and temperature conditions, salt concentration in aqueous solutions, mineral surface chemistry, and geometry. We then review some recent advances in mineral trapping. First, we show that it is possible to reproduce the CO 2 /water/mineral wettability at a wide range of pressures using molecular dynamics (MD) simulations. As the pressure increases, CO 2 gas transforms into a supercritical fluid or liquid at ∼7.4 MPa depending on the environmental temperature. This transition leads to a substantial decrease of the interfacial tension between CO 2 and reservoir brine (or pure water). However, the wettability of CO 2 /water/rock systems depends on the type of rock surface. Recently, we investigated the contact angle of CO 2 /water/silica systems with two different silica surfaces using MD simulations. We found that contact angle increased with pressure for the hydrophobic (siloxane) surface while it was almost constant for the hydrophilic (silanol) surface, in excellent agreement with experimental observations. Furthermore, we found that the CO 2 thin films at the CO 2 -hydrophilic

Interactions among Carbon Dioxide, Heat, and Chemical Lures in Attracting the Bed Bug, Cimex lectularius L. (Hemiptera: Cimicidae

Directory of Open Access Journals (Sweden)

Narinderpal Singh

2012-01-01

Full Text Available Commercial bed bug (Cimex lectularius L. monitors incorporating carbon dioxide (CO2, heat, and chemical lures are being used for detecting bed bugs; however, there are few reported studies on the effectiveness of chemical lures in bed bug monitors and the interactions among chemical lure, CO2, and heat. We screened 12 chemicals for their attraction to bed bugs and evaluated interactions among chemical lures, CO2, and heat. The chemical lure mixture consisting of nonanal, 1-octen-3-ol, spearmint oil, and coriander Egyptian oil was found to be most attractive to bed bugs and significantly increased the trap catches in laboratory bioassays. Adding this chemical lure mixture when CO2 was present increased the trap catches compared with traps baited with CO2 alone, whereas adding heat did not significantly increase trap catches when CO2 was present. Results suggest a combination of chemical lure and CO2 is essential for designing effective bed bug monitors.

Giant Clams and Rising CO2: Light May Ameliorate Effects of Ocean Acidification on a Solar-Powered Animal.

Directory of Open Access Journals (Sweden)

Sue-Ann Watson

Full Text Available Global climate change and ocean acidification pose a serious threat to marine life. Marine invertebrates are particularly susceptible to ocean acidification, especially highly calcareous taxa such as molluscs, echinoderms and corals. The largest of all bivalve molluscs, giant clams, are already threatened by a variety of local pressures, including overharvesting, and are in decline worldwide. Several giant clam species are listed as 'Vulnerable' on the IUCN Red List of Threatened Species and now climate change and ocean acidification pose an additional threat to their conservation. Unlike most other molluscs, giant clams are 'solar-powered' animals containing photosynthetic algal symbionts suggesting that light could influence the effects of ocean acidification on these vulnerable animals. In this study, juvenile fluted giant clams Tridacna squamosa were exposed to three levels of carbon dioxide (CO2 (control ~400, mid ~650 and high ~950 μatm and light (photosynthetically active radiation 35, 65 and 304 μmol photons m-2 s-1. Elevated CO2 projected for the end of this century (~650 and ~950 μatm reduced giant clam survival and growth at mid-light levels. However, effects of CO2 on survival were absent at high-light, with 100% survival across all CO2 levels. Effects of CO2 on growth of surviving clams were lessened, but not removed, at high-light levels. Shell growth and total animal mass gain were still reduced at high-CO2. This study demonstrates the potential for light to alleviate effects of ocean acidification on survival and growth in a threatened calcareous marine invertebrate. Managing water quality (e.g. turbidity and sedimentation in coastal areas to maintain water clarity may help ameliorate some negative effects of ocean acidification on giant clams and potentially other solar-powered calcifiers, such as hard corals.

Giant Clams and Rising CO2: Light May Ameliorate Effects of Ocean Acidification on a Solar-Powered Animal.

Science.gov (United States)

Watson, Sue-Ann

2015-01-01

Global climate change and ocean acidification pose a serious threat to marine life. Marine invertebrates are particularly susceptible to ocean acidification, especially highly calcareous taxa such as molluscs, echinoderms and corals. The largest of all bivalve molluscs, giant clams, are already threatened by a variety of local pressures, including overharvesting, and are in decline worldwide. Several giant clam species are listed as 'Vulnerable' on the IUCN Red List of Threatened Species and now climate change and ocean acidification pose an additional threat to their conservation. Unlike most other molluscs, giant clams are 'solar-powered' animals containing photosynthetic algal symbionts suggesting that light could influence the effects of ocean acidification on these vulnerable animals. In this study, juvenile fluted giant clams Tridacna squamosa were exposed to three levels of carbon dioxide (CO2) (control ~400, mid ~650 and high ~950 μatm) and light (photosynthetically active radiation 35, 65 and 304 μmol photons m-2 s-1). Elevated CO2 projected for the end of this century (~650 and ~950 μatm) reduced giant clam survival and growth at mid-light levels. However, effects of CO2 on survival were absent at high-light, with 100% survival across all CO2 levels. Effects of CO2 on growth of surviving clams were lessened, but not removed, at high-light levels. Shell growth and total animal mass gain were still reduced at high-CO2. This study demonstrates the potential for light to alleviate effects of ocean acidification on survival and growth in a threatened calcareous marine invertebrate. Managing water quality (e.g. turbidity and sedimentation) in coastal areas to maintain water clarity may help ameliorate some negative effects of ocean acidification on giant clams and potentially other solar-powered calcifiers, such as hard corals.

Efficacy of two synthetic food-odor lures for Mexican fruit flies (Diptera: Tephritidae) is determined by trap type.

Science.gov (United States)

Robacker, David C; Czokajlo, Darek

2005-10-01

Sterile mass-reared Mexican fruit flies, Anastrepha ludens (Loew), were trapped in a citrus orchard by using multilure traps and cylindrical sticky traps baited with Advanced Pheromone Technologies Anastrepha fruit fly (AFF) lures or Suterra BioLure two-component (ammonium acetate and putrescine) MFF lures (BioLures). The cylinder trap/AFF lure combination was the best trap over the first 6 wk, the multilure trap/BioLure combination was best during weeks 6-12, and the multilure trap/AFF lure combination was best during the last 6 wk. The multilure trap/BioLure combination was best overall by 36% over the cylinder trap/AFF lure combination, and 57% over the multilure trap/AFF lure combination. Cylinder traps with BioLures were the least effective trap/lure combination throughout the experiment, capturing only half as many flies as cylinder traps with AFF lures. Captures with cylinder traps baited with either lure and multilure traps with BioLures were female biased. For the most part, both lures remained highly attractive and emitted detectable amounts of attractive components under hot field conditions for the duration of the 18-wk experiment. Total emission of ammonia was 4 times greater and 1-pyrroline at least 10 times greater from AFF lures compared with BioLures. Correlations of trap and lure performance with ammonia emission and weather were determined, but no conclusions were possible. Results indicate that BioLures would be the lure of choice in multilure or other McPhail-type traps and AFF lures would be superior with most sticky traps or kill stations that attract flies to outer (not enclosed) surfaces.

Preparation of Cu2O modified TiO2 nanopowder and its application to the visible light photoelectrocatalytic reduction of CO2 to CH3OH

Science.gov (United States)

Li, Bin; Niu, Wenchao; Cheng, Yongwei; Gu, Junjie; Ning, Ping; Guan, Qingqing

2018-05-01

Cu2O/TiO2 nanopowders were prepared and used as thin film electrode raw materials for CO2 photoelectroreduction. Characterization results from XRD, TEM, UV-Vis and BET show that Cu2O/TiO2 composites have regular morphology, narrow band gap, excellent textural properties, and exhibits marked response of visible light. The photoelectrocatalytic results show that CO2 can be reduced to formaldehyde (i.e., intermediate) and finally methanol (i.e., end product). In addition, the CO2 photoelectroreduction pathway and the mechanism of photoelectrocatalysis are discussed. In summary, the work reports a potential method of CO2 reduction by visible-light photocatalysis without an external bias.

Development of a female medfly attractant system in Morocco

International Nuclear Information System (INIS)

Bakri, A.

1999-01-01

Field trials were conducted in Morocco to evaluate food-based attractants according to the FAO/IAEA international network program. Ammonium acetate plus putrescine (FA-2 attractants) were very effective and selective for female medfly attraction. The addition of trimethylamine (FA-3 attractants) increased trap catches. The association of the female attractants with various traps were tested in two medfly host plants, argan (Argania spinosa) and mandarin (Citrus reticulata Blanco) during two seasons (fall and summer). Open bottom dry traps (OBDTs), closed bottom dry traps (CBDTs), dry International Pheromone's McPhail traps (IPMTs), wet IPMTs, locally made traps and Tephri traps, all baited with the synthetic lures (FA-2 and FA-3), were compared to liquid protein baited IPMTs and Trimedlure baited Jackson traps. Results showed that the new trapping systems were as effective in capturing females as the standard IPMT baited with NuLure + borax. Furthermore, dry Tephri traps were the most effective under certain conditions. Only in one experiment were CBDTs baited with the synthetic two component lure (FA-2) as effective as Trimedlure baited Jackson traps. In most cases the attracted females were immature. Attempts to increase the attractiveness of the synthetic lure by the addition of male medfly synthetic pheromone failed. Based on the results obtained, it is apparent that the three component synthetic female attractant (FA-3) provides an effective system for capturing female medflies and could be used as an alternative to NuLure baited IPMT traps for assessing the efficacy of SIT when sterile males are released. (author)

Motion analysis of optically trapped particles and cells using 2D Fourier analysis

DEFF Research Database (Denmark)

Kristensen, Martin Verner; Ahrendt, Peter; Lindballe, Thue Bjerring

2012-01-01

Motion analysis of optically trapped objects is demonstrated using a simple 2D Fourier transform technique. The displacements of trapped objects are determined directly from the phase shift between the Fourier transform of subsequent images. Using end-and side-view imaging, the stiffness...... of the trap is determined in three dimensions. The Fourier transform method is simple to implement and applicable in cases where the trapped object changes shape or where the lighting conditions change. This is illustrated by tracking a fluorescent particle and a myoblast cell, with subsequent determination...

Thermoluminescence properties of Eu and Li co-doped Gd2O3, induced by UV light

International Nuclear Information System (INIS)

Hristov, H; Arhangelova, N; Velev, V; Uzunov, N M; Baneva, Y; Nedeva, D; Penev, I; Moschini, G; Rossi, P

2012-01-01

For some specific biomedical applications, connected with in-situ measurements of the absorbed dose of ultraviolet (UV) light, we have developed materials, sensitive to the light emission with a wavelength up to 320nm. Thermoluminescence (TL) yield of Gd 2 O 3 , doped with Eu and Li has been analysed with respect to the quantity of Li co-dopant. Lithium has been added as Li 2 CO 3 to a mixture of Gd 2 O 3 with 10 wt% Eu 2 O 3 . Pellets with the mixture have been sintered at a temperature of 1000°C. The kinetic parameters of the phosphors thus obtained have been studied from the TL glow curves after irradiation with UV light. It has been demonstrated that the addition of 16 wt% of Li 2 CO 3 to the Eu-doped Gd 2 O 3 yields a maximum intensity of the peaks at 87°C and at 145°C. Studies on the kinetic parameters as well as the TL properties of Eu-doped Gd 2 O 3 with the addition of 16% of Li 2 CO 3 have been conducted. It has been measured that two of the TL peaks of this phosphor have relatively long fading. Analysis of the TL properties of the phosphors obtained from Gd 2 O 3 , doped with Eu and Li, shows that they possess good sensitivity to the UV emission and could be used as appropriate phosphors for detection and quantitative measurements of UV light.

Reductive trapping of [(OC){sub 5}W-W(CO){sub 5}]{sup 2-} in a mixed-valent Sm{sup II/III} calix[4]pyrrolide sandwich

Energy Technology Data Exchange (ETDEWEB)

Deacon, Glen B.; Guo, Zhifang [School of Chemistry, Monash University, VIC (Australia); Junk, Peter C.; Wang, Jun [College of Science and Engineering, James Cook University, Townsville, QLD (Australia)

2017-07-10

Reduction of tungsten hexacarbonyl by the divalent samarium(II) complex [Sm{sub 2}(N{sub 4}Et{sub 8})(thf){sub 4}] ((N{sub 4}Et{sub 8}){sup 4-}=meso-octaethylcalix[4]pyrrolide) in toluene at ambient temperature gave the remarkable heteronuclear mixed-valent samarium(II/III)/tungsten complex [{(thf)_2Sm"I"I(N_4Et_8)Sm"I"I"I(thf)}{sub 2}{(μ-OC)_2W_2(CO)_8}], which features the trapping of a rare [W{sub 2}(CO){sub 10}]{sup 2-} anion with an unsupported W-W bond. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Rain events decrease boreal peatland net CO2 uptake through reduced light availability.

Science.gov (United States)

Nijp, Jelmer J; Limpens, Juul; Metselaar, Klaas; Peichl, Matthias; Nilsson, Mats B; van der Zee, Sjoerd E A T M; Berendse, Frank

2015-06-01

Boreal peatlands store large amounts of carbon, reflecting their important role in the global carbon cycle. The short-term exchange and the long-term storage of atmospheric carbon dioxide (CO2 ) in these ecosystems are closely associated with the permanently wet surface conditions and are susceptible to drought. Especially, the single most important peat forming plant genus, Sphagnum, depends heavily on surface wetness for its primary production. Changes in rainfall patterns are expected to affect surface wetness, but how this transient rewetting affects net ecosystem exchange of CO2 (NEE) remains unknown. This study explores how the timing and characteristics of rain events during photosynthetic active periods, that is daytime, affect peatland NEE and whether rain event associated changes in environmental conditions modify this response (e.g. water table, radiation, vapour pressure deficit, temperature). We analysed an 11-year time series of half-hourly eddy covariance and meteorological measurements from Degerö Stormyr, a boreal peatland in northern Sweden. Our results show that daytime rain events systematically decreased the sink strength of peatlands for atmospheric CO2 . The decrease was best explained by rain associated reduction in light, rather than by rain characteristics or drought length. An average daytime growing season rain event reduced net ecosystem CO2 uptake by 0.23-0.54 gC m(-2) . On an annual basis, this reduction of net CO2 uptake corresponds to 24% of the annual net CO2 uptake (NEE) of the study site, equivalent to a 4.4% reduction of gross primary production (GPP) during the growing season. We conclude that reduced light availability associated with rain events is more important in explaining the NEE response to rain events than rain characteristics and changes in water availability. This suggests that peatland CO2 uptake is highly sensitive to changes in cloud cover formation and to altered rainfall regimes, a process hitherto largely

Management of Cosmopolites sordidus and Metamasius hemipterus in banana by pheromone-based mass trapping.

Science.gov (United States)

Alpizar, D; Fallas, M; Oehlschlager, A C; Gonzalez, L M

2012-03-01

Mass trapping Cosmopolites sordidus (Coleoptera, Curculionidae) using a pheromone-baited pitfall trap and Metamasius hemipterus (Coleoptera, Curculionidae) using a pheromone-sugarcane-baited open gallon trap was conducted in commercial banana. Four traps for each insect per hectare were placed in each of two 5-hectare plots of banana. Two additional 5-hectare plots were designated as controls and treated according to the plantation protocol. Capture rates of C. sordidus and M. hemipterus declined by >75 % over 10-12 months. In the banana growing region studied, corm damage was due primarily to C. sordidus, while only a minor amount of damage was attributable to M. hemipterus. Corm damage reduction in trapping plots was, thus, attributed primarily to C. sordidus trapping. In trapping plots, corm damage decreased by 61-64 % during the experiment. Banana bunch weights increased 23 % relative to control plots after 11-12 months of trapping. Fruit diameter did not vary between bunches harvested from trapping plots vs. control plots. Plant vigor, however, as determined by stem circumference at one meter above ground increased in plots with traps compared to control plots. Trapping for C. sordidus in two plantations of over 200 hectares each, reduced corm damage 62-86 % relative to pre-trapping levels. Insecticide control measures in place when the experiment commenced resulted in about 20-30 % corm damage, while use of pheromone trapping to manage C. sordidus lowered corm damage to 10 % or less. It is estimated that the increase in value of increased yield obtained in this trial (23 %) is about $4,240 USD per year per hectare, while the cost of pheromone trapping is approximately $185 USD per year per hectare. The trapping program becomes revenue neutral if bunch weights increase by an average of 1 % per year of trapping. Approximately 10 % of all plantation area in Costa Rica use the pheromone trapping system described here. The system also is used in Martinique

Development of female medfly attractant systems for trapping and sterility assessment. Proceedings of a final research co-ordination meeting

International Nuclear Information System (INIS)

1999-07-01

Practical application of the sterile insect technique (SIT) against major insect pests will continue to increase as the repeated use of insecticides is recognized as an environmental problem. In the case of the Mediterranean fruit fly (medfly), which attacks over 300 species of fruits and vegetables in tropical, subtropical, and temperate climates on all five continents, control is still largely based on frequent insecticide spraying, often more than 10 sprays per fruiting season. Methods for population estimation, which accurately reflect changes due to movement, mortality or reproduction, are a prerequisite for effective pest management and in particular for use of SIT. With better monitoring tools medfly populations can be estimated more accurately and compared under different conditions, to guide decisions on alternative (i.e. more effective and more environment-friendly) control strategies. In support of this need in the application of SIT field programmes against medfly, an FAO/IAEA co-ordinated research project (CRP) was carried out which resulted in a TECDOC published in 1996 on Standardization of Medfly Trapping for Use in sterile insect technique Programmes. Following the development of male only genetic sexing strains at the FAO/IAEA Agriculture and Biotechnology Laboratories in Seibersdorf, Austria, it was recognized that the development of a female medfly targeted trapping system, in conjunction with only male sterile releases, would improve the efficacy of the SIT, reduce costs, and more effectively utilize sterile males. As a result, a new FAO/IAEA Co-ordinated Research Project on Development of Female Medfly Attractant Systems for Trapping and Sterility Assessment was initiated in 1994 with the objective to develop new synthetic female medfly attractants and to determine their efficacy compared to proteinaceous baits under different weather, host-tree and population density conditions. Findings obtained during the course of this 5-year CRP are

Development of female medfly attractant systems for trapping and sterility assessment. Proceedings of a final research co-ordination meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01