Bottomâ up vs reactive sintering of Al2O3â YAGâ YSZ composites via one or threeâ phase nanoparticles (NPs). Bottomâ up processing wins this time

The bottomâ up approach describes the synthesis of bulk materials from the finest possible length scales to obtain the best global properties. This approach was adapted to the synthesis of multiâ phase ceramic composites produced from metal oxides produced by liquidâ feed flame spray pyrolysis (LFâ FSP). The effect of length scale of mixing was tested through two processing schemes, mixed single metalâ oxide nanopowders (NPs) and nanocomposite NPs having the desired composition within single particles. For the Al2O3â Y2O3â ZrO2 ternary system, composites prepared from nanostructured nanoparticles sinter to finer grain sizes (<410 nm) at equivalent densities of 95%TD than those prepared from mixed nanoparticle processing. These contrast with our previous studies in this area where mixed NP processing gave the best or equivalent results. The nanocomposite NPs produced in this study exhibit novel nanostructures with three phases contained within single particles <26 nm average particle size (APS). This nanostructure may directly explain the enhanced sintering of the nanocomposite NPs and may provide an impetus for future synthesis of similarly structured NPs.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137592/1/jace14761.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137592/2/jace14761_am.pd

Processing YAG/뱉 Al2O3 composites via reactive sintering Y2O3/Al2O3 NP mixtures. A superior alternative to bottom up processing using atomically mixed YAlOx NPs

This effort contrasts â bottomâ upâ processing of YAG/αâ Al2O3 composites where both elements (as 40â 50 nm APSs nanopowders) are present at close to atomic mixing with reactive sintering where ballâ milled mixtures of the individual nanopowders (40â 50 nm APSs) give uniform elemental mixing at length scales closer to 100â 800 nm with correspondingly much longer diffusion distances. In contrast to expectations, densification with control of final grain sizes is best effected using reactive sintering. Thus, reactive sintering to densities â ¥95% occurs at only 1500°C with final grain sizes of â 1000 nm for all samples. In contrast â bottom upâ processing to â ¥95% densities is only achieved at 1600°C, and with final grain sizes of 1700 nm. The reason for this unexpected behavior is that YAG phase forms early in the bottom up approach greatly inhibiting diffusion promoted densification. In contrast, in reactive sintering, YAG is prevented from forming because of the longer diffusion distances such that densification occurs prior to full conversion of the Y2O3 component to YAG. The found hardness values are statistically superior to literature values for composites near the known eutectic composition. In an accompanying paper, the addition of a third component reverses this behavior.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138233/1/jace14980_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138233/2/jace14980.pd

Potential for integrating Neochetina eichhorniae (Coleoptera: Culionidae) and phytopathogenic fungi to control water hyacinth

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Révision du genre Poeonoma Tams & Bowden (Lepidoptera : Noctuidae : Apameiini : Sesamiina) avec la description d’un nouveau genre et de deux nouvelles espèces de Sesamiina de la région afrotropicale

The genus Poeonoma (Tams & Bowden, 1953) is revised to include two species P. serrata (Hampson, 1910) and P. ugandensis Le Run. sp., from the Congolian bioregion. Several new synonyms are introduced for Poeonoma serrata: Conicofrontia sjoestedti (Aurivillius, 1925) n. syn. for Poeonoma serrata (Hampson, 1910), Poeonoma similis (Tams & Bowden, 1953) n. syn. for Poeonoma serrata (Hampson, 1910), and Poeonoma nigribasis (Laporte, 1974) n. syn. for Poeonoma serrata (Hampson, 1910). A new genus, Nyaluteme Le Run. gen., is proposed for two species formerly included in Poeonoma, N. acantha (Tams & Bowden, 1953) n. comb. and N. inermis (Laporte, 1973) n. comb., and N. nigra Le Run. sp., described from the Congolian bioregion. Host-plants for three of the species are recorded:Pennisetum purpureum Schumach. for P. serrata and P. ugandensis, and Miscanthus violaceus (K. Schum) Pilg. for N. nigra. A key to species, descriptions, illustrations of adults and genitalia, and distribution maps are included. Results of previously published phylogenetic analyses also allow the status of the new genus to be confirmed and to infer the phylogenetic placement of the two genera.Le genre Poeonoma (Tams & Bowden, 1953) est révisé ; deux espèces, P. serrata (Hampson, 1910) et P. ugandensis Le Ru n. sp., de la biorégion Congolaise, y sont incluses et plusieurs nouvelles synonymies sont proposées pour Poeonoma serrata : Conicofrontia sjoestedti (Aurivillius, 1925) n. syn. de Poeonoma serrata (Hampson, 1910), Poeonoma similis (Tams & Bowden, 1953) n. syn. de Poeonoma serrata (Hampson, 1910), et Poeonoma nigribasis (Laporte, 1974) n. syn. de Poeonoma serrata (Hampson, 1910). Un nouveau genre, Nyaluteme Le Ru n. gen., de la biorégion Congolaise, est proposé pour deux espèces précédemment décrites dans le genre Poeonoma, N. acantha (Tams & Bowden, 1953) n. comb., et N. inermis (Laporte, 1973) n. comb., et une espèce nouvellement décrite N. nigra Le Ru n. sp. Les plantes-hôtes de trois espèces sont répertoriées : Pennisetum purpureum Schumach. pour P. serrata et P. ugandensis, et Miscanthus violaceus (K. Schum) Pilg. pour N. nigra. Une clé de détermination des espèces est présentée ainsi que l’illustration des adultes et des génitalia et, des cartes de distribution. Les résultats d’analyses de reconstruction phylogénétique déjà publiées permettent également de confirmer le statut du nouveau genre et d’inférer la position phylogénétique des deux genres. http://www.zoobank.org/urn:lsid:zoobank.org:pub:6ED4AC9E-043C-4A04-A92D-80706694300

Molecular phylogenetics and definition of the Acrapex minima Janse group (Lepidoptera, Noctuidae, Apameini, Sesamiina) with the description of four new species from the Afrotropics

International audienceFive morphologically similar species of Acrapex Hampson (Lepidoptera, Noctuidae, Noctuinae, Apameini), from sub-Saharan Africa are reviewed, including four new species that are described: Acrapex mondogeneta Le Ru n. sp., A. mubale Le Ru n. sp., A. robe Le Ru n. sp. and A. rubona Le Ru n. sp. These five species belong to a species complex that we hereby define as the Acrapex minima group. Host plants of three species are recorded; Acrapex minima is recorded for the first time on a host plant, Digitaria natalensis Stent; A. mondogeneta on Hyparrhenia hirta (L.) Stapf and A. rubona on Imperata cylindrica (L.) P. Beauv. We also conducted molecular phylogenetics (using both Bayesian inference and maximum likelihood) and molecular species delimitation analyses (Poisson tree processes) on a six gene multi-marker dataset (four mitochondrial and two nuclear gene fragments; 4582 nucleotides in length) of 42 specimens and 22 species, including 23 specimens from the Acrapex minima group. The results of the corresponding analyses support the monophyly of the group and the species status of the newly described taxa

Phylogenetic analysis and systematics of the Acrapex unicolora Hampson species complex (Lepidoptera, Noctuidae, Apameini), with the description of five new species from the Afrotropics

Ten morphologically similar species of Acrapex Hampson, 1891 (Lepidoptera, Noctuidae, Noctuinae, Apameini) from Central and Eastern Africa are reviewed, including five new species: Acrapex kafula le Ru sp. nov., A. kavumba le Ru sp. nov., A. kiakouama le Ru sp. nov., A. miscantha le Ru sp. nov. and A. simillima le Ru sp. nov. Evidence is provided to transfer the monotypic genus Poecopa Bowden, 1956 to the genus Acrapex. Host plants of five species are recorded, some of them for the first time. Acrapex kavumba sp. nov., A. miscantha sp. nov. and A. simillima sp. nov. were found on one host plant each. Acrapex mediopuncta, previously reported in West Africa from Pennisetum purpureum Schumach., Rottboellia compressa L., Setaria megaphylla (Steud) Dur. & Schinz. and Sorghum arundinaceum (Desv.) Stapf, was only found from S. megaphylla in Central Africa. Larvae of Acrapex unicolora were collected on Andropogon gayanus Kunth, Chrysopogon zizanoides (L.) Roberty, Cymbopogon schoenanthus subsp. proximus (Hochst. ex A.Rich.) Maire & Weller, Cymbopogon pospischiilii (K.Schum.) C.E.Hubb., Hyparrhenia diplandra (Hack.) Stapf and Setaria sphacelata (Schumach.) Moss. We also conducted molecular phylogenetic analyses (using maximum likelihood) and molecular species delimitation analyses on a comprehensive sample of 61 specimens belonging to eight of the studied species. Molecular phylogenetic analyses provided additional evidence of the synonymy of Acrapex and Poecopa, whereas molecular species delimitation analyses support the validity of the five newly described species and unravel another potential new species, only collected in the larval stage

Phylogenetics, integrative taxonomy and systematics of the Sesamia cretica species group (Lepidoptera: Noctuidae: Apameini: Sesamiina), with the description of 21 new species from the Afrotropical region

International audienceIn this study, 31 species of noctuid stemborers belonging to the genus Sesamia Guenee, 1852 (Lepidoptera: Noctuidae: Noctuinae: Apameini: Sesamiina) are reviewed. All these species are assigned to the Sesamia cretica group sensu Tams & Bowden (1953). Based on genitalic characters, several subgroups are hereby defined. Nine species belong to a species complex defined as the Sesamia albivena Hampson, 1902 subgroup; it consists of S. albivena, S. mocoensis Tams & Bowden, 1953, n. stat., S. sudanensis Tams & Bowden, 1953, n. stat. S. taenioleuca (Wallengren, 1863), and five new species that are described (S. aethiopica Le Ru n. sp. from Ethiopia, S. kafulo Le Ru n. sp. from Botswana and Zambia, S. kavirondo Le Ru n. sp. from Kenya and Uganda, S. maloukou Le Ru n. sp. from Republic of Congo, and S. soyema Le Ru n. sp. from Ethiopia). Four species belong to a species complex defined as the Sesamia cretica subgroup; this encompasses S. cretica, S. rufescens Hampson, 1910, and two new species that are described (S. ihambane Le Ru n. sp. from Mozambique and Tanzania and S. kikuyuensis Le Ru n. sp. from Kenya); two new synonyms are introduced for Sesamia cretica: Nonagria uniformis Dudgeon, 1905 n. syn. and Sesamia griselda Warren, 1913, n. syn. Ten species belong to a species complex defined as the Sesamia fuscifrontia Hampson, 1914 subgroup; this includes S. fuscifrontia, S. geyri (Strand, 1915) and eight new species that are described (S. babati Le Ru n. sp. from Tanzania, S. babessi Le Ru n. sp. from Cameroon and Zambia, S. mabira Le Ru n. sp. from Uganda, S. nangaensis Le Ru n. sp. from Cameroon and Republic of Congo, S. rungwa Le Ru n. sp. from Tanzania, S. simillima Le Ru n. sp. from Benin, Cameroon, Kenya and Uganda, S. taveta Le Ru n. sp. from Kenya and S. ulaukae Le Ru n. sp. from Ethiopia). One species belongs to a species complex defined as the Sesamia salama Le Ru n. sp. subgroup; this consists of S. salama Le Ru n. sp. from Kenya and another undescribed Sesamia species from South Africa. One species belongs to a species complex defined as the Sesamia viettei Rungs, 1954 subgroup. Six species belong to a species complex defined as the Sesamia wiltshirei Rungs, 1963 subgroup; this groups S. wiltshirei and five new species that are described (S. djenoensis Le Ru n. sp. from Republic of Congo, S. inexpectata Le Ru n. sp. from South Africa and Zambia, S. lefini Le Ru n. sp. from Republic of Congo, S. echinochloa Le Ru n. sp. from Botswana, Kenya, Mozambique, South Africa, Tanzania and Zambia and S. rindini Le Ru n. sp. from Tanzania). A supplemental description of the previously described species is also provided. Novel host plant records are also provided for 11 species of the S. cretica group. To complement the morphological study, both phylogenetic and molecular species delimitation analyses were carried out on a multimarker (four mitochondrial and two nuclear genes) molecular dataset encompassing 144 specimens representing 35 species (including 25 species from the S. cretica group). Molecular analyses provide a well-supported phylogenetic framework for the species of interest, which are all recovered monophyletic. Molecular species delimitation analyses also support the species status of almost all sampled species. Interestingly, the inferred tree indicates that the S. cretica group and the S. fuscifrontia subgroup are both paraphyletic; this indicates that, while highly informative, the chosen genitalic characters in Sesamia are not all synapomorphies