Manufacturing of self-passivating tungsten based alloys by different powder metallurgical routes

Self-passivating tungsten based alloys will provide a major safety advantage compared to pure tungsten when used as first wall armor of future fusion reactors, due to the formation of a protective oxide layer which prevents the formation of volatile and radioactive WO3 in case of a loss of coolant accident with simultaneous air ingress. Bulk WCr10Ti2 alloys were manufactured by two different powder metallurgical routes: (1) mechanical alloying (MA) followed by hot isostatic pressing (HIP) of metallic capsules, and (2) MA, compaction, pressureless sintering in H2 and subsequent HIPing without encapsulation. Both routes resulted in fully dense materials with homogeneous microstructure and grain sizes of 300 nm and 1 μm, respectively. The content of impurities remained unchanged after HIP, but it increased after sintering due to binder residue. It was not possible to produce large samples by route (2) due to difficulties in the uniaxial compaction stage. Flexural strength and fracture toughness measured on samples produced by route (1) revealed a ductile-to-brittle-transition temperature (DBTT) of about 950 °C. The strength increased from room temperature to 800 °C, decreasing significantly in the plastic region. An increase of fracture toughness is observed around the DBTT.

Two routes of chlorophyllide synthesis that are differentially regulated by light in barley (Hordeum vulgare L.).

NADPH-protochlorophyllide oxidoreductase (POR; EC 1.6.99.1) catalyzes the only known light-dependent step in chlorophyll synthesis of higher plants, the reduction of protochlorophyllide (Pchlide) to chlorophyllide. In barley, two distinct immunoreactive POR proteins were identified. In contrast to the light-sensitive POR enzyme studied thus far (POR-A), levels of the second POR protein remained constant in seedlings during the transition from dark growth to the light and in green plants. The existence of a second POR-related protein was verified by isolating and sequencing cDNAs that encode a second POR polypeptide (POR-B) with an amino acid sequence identity of 75% to the POR-A. In the presence of NADPH and Pchlide, the in vitro-synthesized POR-A and POR-B proteins could be reconstituted to ternary enzymatically active complexes that reduced Pchlide to chlorophyllide only after illumination. Even though the in vitro activities of the two enzymes were similar, the expression of their genes during the light-induced transformation of etiolated to green seedlings was distinct. While the POR-A mRNA rapidly declined during illumination of dark-grown seedlings and soon disappeared, POR-B mRNA remained at an approximately constant level in dark-grown and green seedlings. Thus these results suggest that chlorophyll synthesis is controlled by two light-dependent POR enzymes, one that is active only transiently in etiolated seedlings at the beginning of illumination and the other that also operates in green plants.

Avaliação da durabilidade de misturas asfálticas a quente e mornas contendo material asfáltico fresado.

A reciclagem de misturas asfálticas usando técnicas de misturas mornas atende às exigências da sustentabilidade, limitando o consumo de energia e de novos materiais. A reciclagem de revestimentos asfálticos fresados (RAP) é praticada há mais de 40 anos, por meio de usinagem a quente do RAP adicionado a agregados e ligante novos. Todavia, o uso de elevadas taxas de RAP (acima de 25% no total), é um grande desafio até o presente, pois limita a perda de durabilidade da mistura asfáltica final. O RAP contém ligante asfáltico envelhecido aderido aos agregados, porém uma parte desse ligante pode ser remobilizada durante a reciclagem pelo aumento da temperatura no processo de usinagem. Esta tese busca compreender o processo de remobilização do ligante envelhecido durante a reciclagem do RAP e as consequências da magnitude de temperatura empregada no processo de reaquecimento deste material envelhecido. Atualmente, tem-se buscado o uso da tecnologia de usinagem morna, permitindo a redução de temperatura total no processo de fabricação. Um dos problemas possíveis da combinação das técnicas reciclagem morna é a ocorrência do fenômeno de recobrimento duplo, que pode impactar na reologia do novo material: o ligante do RAP e o ligante novo não se misturariam totalmente, devido à redução das temperaturas de fabricação, formando camadas superpostas. Este fenômeno seria a causa de disfuncionamentos mecânicos da mistura asfáltica final. Questiona-se então a qualidade do recobrimento dos agregados do RAP, já recobertos, e a falta de um meio de caracterização para a observação da interface. Neste estudo, a qualidade do recobrimento do RAP foi avaliada em escala microscópica e macroscópica. No nível microscópico, foi proposto o uso de uma ferramenta de micro-espectroscopia infravermelha para avaliar a interface entre o RAP e o ligante novo, e seguir a distribuição espacial desses dois componentes na mistura asfáltica. Para tanto, foi realizado um desenvolvimento experimental detalhado que permitisse o uso de um acessório de imagem infravermelha em misturas asfálticas recicladas. Graças à indentificação prévia de marcadores internos, foi possível acompanhar a mobilização parcial do ligante envelhecido do RAP. Em paralelo, no nível macroscópico, foi desenvolvido um protocolo de ensaio com o objetivo de avaliar a durabilidade das misturas asfálticas recicladas com taxas elevadas de RAP (50%), com o objetivo princial de compreender se há benefícios nas propriedades mecânicas de misturas mornas recicladas. O ensaio de fadiga é um dos ensaios que permitem melhor avaliar e comparar diferentes misturas asfálticas para comporem uma camada de pavimento. Porém, este ensaio não pode ser diretamente transposto à previsibilidade de campo por ter restrições, tais como o ligante das amostras ensaiadas não teve tempo de envelhecer; e as misturas asfálticas, dependendo da quantidade de RAP e da temperatura de usinagem, podem envelhecer em velocidades diferentes em campo. No presente trabalho, foi proposta a adição de uma etapa de envelhecimento previamente aos ensaios mecânicos. Foi suposto que o comportamento real do material estaria situado entre o do material não envelhecido e do envelhecido. Os principais resultados mostram que uma mistura reciclada morna apresenta resultados satisfatórios de comportamento mecânico que atestam seu uso como camada de revestimento asfáltico, exceto que ela tem a tendência de ser mais sensível à fadiga que uma mistura com a mesma composição de agregados e de teor de ligante, fabricada a quente ou morna, mas sem a adição de RAP.

Matériaux pour la faune du Congo : Poissons nouveaux / par G. A. Boulenger ; planches dessinées, sous la direction de l'auteur, par P. J. Smit et J. Green.

ser.1:t.1:fasc.2

Matériaux pour la faune du Congo : Poissons nouveaux / par G. A. Boulenger ; planches dessinées, sous la direction de l'auteur, par P. J. Smit et J. Green.

ser.1:t.1:fasc.1

World Map Showing Routes of Exploration and Discovery, 1790 (Image 1 of 8) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Chart of the world on Mercators projection : exhibiting all the new discoveries to the present time, with the tracks of the most distinguished navigators since the year 1700 carefully collected from the best charts, maps, voyages, &c. extant and regulated from the accurate astronomical observations made in three voyages performed under the command of Captn. James Cook in the years 1768, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 & 80, compiled and published by A. Arrowsmith, geographer; by permission of Simon McTavish Esq[r] is correctly delineated the discoveries of Mr. McKenzie laid down from his original journal in the year 1789. It was published by A. Arrowsmith, April 1, 1790. Scale [ca. 1:20,000,000]. This layer is image 1 of 8 total images of the seven sheet source map. Covers portions of eastern Asia, Siberia, Russia, Pacific Islands, and western portions of Canada and the United States including Alaska. The image inside the map neatline is georeferenced to the surface of the earth and fit to a non-standard 'World Mercator' projection, with the central meridian at 180 degrees west. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. Note: The central meridian of this map is not the same as the Prime Meridian and may wrap the International Date Line or overlap itself when displayed in GIS software. This map shows features such as drainage, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown by hachures. Depths shown by soundings. Includes routes, locations, and dates of James Cook's voyages. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.

World Map Showing Routes of Exploration and Discovery, 1790 (Image 2 of 8) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Chart of the world on Mercators projection : exhibiting all the new discoveries to the present time, with the tracks of the most distinguished navigators since the year 1700 carefully collected from the best charts, maps, voyages, &c. extant and regulated from the accurate astronomical observations made in three voyages performed under the command of Captn. James Cook in the years 1768, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 & 80, compiled and published by A. Arrowsmith, geographer; by permission of Simon McTavish Esq[r] is correctly delineated the discoveries of Mr. McKenzie laid down from his original journal in the year 1789. It was published by A. Arrowsmith, April 1, 1790. Scale [ca. 1:20,000,000]. This layer is image 2 of 8 total images of the seven sheet source map. Covers portions of Europe, Northern Africa, and Asia. The image inside the map neatline is georeferenced to the surface of the earth and fit to the 'World Mercator' projection. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown by hachures. Depths shown by soundings. Includes routes, locations, and dates of James Cook's voyages. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.

World Map Showing Routes of Exploration and Discovery, 1790 (Image 3 of 8) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Chart of the world on Mercators projection : exhibiting all the new discoveries to the present time, with the tracks of the most distinguished navigators since the year 1700 carefully collected from the best charts, maps, voyages, &c. extant and regulated from the accurate astronomical observations made in three voyages performed under the command of Captn. James Cook in the years 1768, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 & 80, compiled and published by A. Arrowsmith, geographer; by permission of Simon McTavish Esq[r] is correctly delineated the discoveries of Mr. McKenzie laid down from his original journal in the year 1789. It was published by A. Arrowsmith, April 1, 1790. Scale [ca. 1:20,000,000]. This layer is image 3 of 8 total images of the seven sheet source map. Covers portions of South America, the South Pacific and the South Atlantic. The image inside the map neatline is georeferenced to the surface of the earth and fit to the 'World Mercator' projection. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown by hachures. Depths shown by soundings. Includes routes, locations, and dates of James Cook's voyages. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.

World Map Showing Routes of Exploration and Discovery, 1790 (Image 5 of 8) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Chart of the world on Mercators projection : exhibiting all the new discoveries to the present time, with the tracks of the most distinguished navigators since the year 1700 carefully collected from the best charts, maps, voyages, &c. extant and regulated from the accurate astronomical observations made in three voyages performed under the command of Captn. James Cook in the years 1768, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 & 80, compiled and published by A. Arrowsmith, geographer; by permission of Simon McTavish Esq[r] is correctly delineated the discoveries of Mr. McKenzie laid down from his original journal in the year 1789. It was published by A. Arrowsmith, April 1, 1790. Scale [ca. 1:20,000,000]. This layer is image 5 of 8 total images of the seven sheet source map. Covers portions of North America, northern South America, and the western coasts of Europe and Africa. The image inside the map neatline is georeferenced to the surface of the earth and fit to the 'World Mercator' projection. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown by hachures. Depths shown by soundings. Includes routes, locations, and dates of James Cook's voyages. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.

World Map Showing Routes of Exploration and Discovery, 1790 (Image 4 of 8) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Chart of the world on Mercators projection : exhibiting all the new discoveries to the present time, with the tracks of the most distinguished navigators since the year 1700 carefully collected from the best charts, maps, voyages, &c. extant and regulated from the accurate astronomical observations made in three voyages performed under the command of Captn. James Cook in the years 1768, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 & 80, compiled and published by A. Arrowsmith, geographer; by permission of Simon McTavish Esq[r] is correctly delineated the discoveries of Mr. McKenzie laid down from his original journal in the year 1789. It was published by A. Arrowsmith, April 1, 1790. Scale [ca. 1:20,000,000]. This layer is image 4 of 8 total images of the seven sheet source map. Covers portions of Southern Africa, Southeast Asia, Western Australia, and the Indian Ocean. The image inside the map neatline is georeferenced to the surface of the earth and fit to the 'World Mercator' projection. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown by hachures. Depths shown by soundings. Includes routes, locations, and dates of James Cook's voyages. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.

World Map Showing Routes of Exploration and Discovery, 1790 (Image 6 of 8) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Chart of the world on Mercators projection : exhibiting all the new discoveries to the present time, with the tracks of the most distinguished navigators since the year 1700 carefully collected from the best charts, maps, voyages, &c. extant and regulated from the accurate astronomical observations made in three voyages performed under the command of Captn. James Cook in the years 1768, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 & 80, compiled and published by A. Arrowsmith, geographer; by permission of Simon McTavish Esq[r] is correctly delineated the discoveries of Mr. McKenzie laid down from his original journal in the year 1789. It was published by A. Arrowsmith, April 1, 1790. Scale [ca. 1:20,000,000]. This layer is image 6 of 8 total images of the seven sheet source map. Covers portions of Australia, Southeast Asia, and the South Pacific Ocean. The image inside the map neatline is georeferenced to the surface of the earth and fit to a non-standard 'World Mercator' projection, with the central meridian at 180 degrees west. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. Note: The central meridian of this map is not the same as the Prime Meridian and may wrap the International Date Line or overlap itself when displayed in GIS software. This map shows features such as drainage, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown by hachures. Depths shown by soundings. Includes routes, locations, and dates of James Cook's voyages. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.

World Map Showing Routes of Exploration and Discovery, 1790 (Image 8 of 8) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Chart of the world on Mercators projection : exhibiting all the new discoveries to the present time, with the tracks of the most distinguished navigators since the year 1700 carefully collected from the best charts, maps, voyages, &c. extant and regulated from the accurate astronomical observations made in three voyages performed under the command of Captn. James Cook in the years 1768, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 & 80, compiled and published by A. Arrowsmith, geographer; by permission of Simon McTavish Esq[r] is correctly delineated the discoveries of Mr. McKenzie laid down from his original journal in the year 1789. It was published by A. Arrowsmith, April 1, 1790. Scale [ca. 1:20,000,000]. This layer is image 8 of 8 total images of the seven sheet source map. Covers portions of eastern Asia. The original map sheet contains multiple maps on one sheet. Because the map images are non-contiguous and possibly at differing scales, each map image was georeferenced separately. The image inside the map neatline is georeferenced to the surface of the earth and fit to the 'Mercator' projection. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown by hachures. Depths shown by soundings. Includes routes, locations, and dates of James Cook's voyages. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.

World Map Showing Routes of Exploration and Discovery, 1790 (Image 7 of 8) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Chart of the world on Mercators projection : exhibiting all the new discoveries to the present time, with the tracks of the most distinguished navigators since the year 1700 carefully collected from the best charts, maps, voyages, &c. extant and regulated from the accurate astronomical observations made in three voyages performed under the command of Captn. James Cook in the years 1768, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 & 80, compiled and published by A. Arrowsmith, geographer; by permission of Simon McTavish Esq[r] is correctly delineated the discoveries of Mr. McKenzie laid down from his original journal in the year 1789. It was published by A. Arrowsmith, April 1, 1790. Scale [ca. 1:20,000,000]. This layer is image 7 of 8 total images of the seven sheet source map. Covers portions of Australia and Southeast Asia. The original map sheet contains multiple maps on one sheet. Because the map images are non-contiguous and possibly at differing scales, each map image was georeferenced separately. The image inside the map neatline is georeferenced to the surface of the earth and fit to the 'Mercator' projection. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown by hachures. Depths shown by soundings. Includes routes, locations, and dates of James Cook's voyages. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.

World Map Showing Routes of Exploration and Discovery, 1853 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Planisphere : elémentaire et illustré indiquant la description géographique des parties connues de la terre, l'époque des grandes découvertes des navigateurs les colonies Européennes, les principaux parcours des paquebots, l'époque des départs, la durée du trajet, &c[a]., dreseé par Vuillemin, géographie ; gravé par Langevin. It was published by Fatout in 1853. Scale [ca. 1:50,000,000]. Map in French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the the 'World Mercator' projection. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, territorial boundaries, shoreline features, and more. Shows voyage routes of exploration and discovery. Relief shown pictorially and by spot heights. Includes historical notes, explanations, and ill. of sea vessels and scenes of exploration. Includes insets at lower margin: Costumes des différentes races qui peuplent la terre -- [Chart of Mt. heights in Europe] -- Hauteur des principales montagnes du monde -- [Chart of Mt. heights in Asia] -- Tableau faisant voir que le Planisphère n'est que le développement figure du globe sur une surface plane -- Longueurs sources et embouchures des principaux fleuves du monde -- Costumes des différentes races qui peuplent la terre. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.

World Map Showing Routes of Exploration and Discovery, 1850 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: The world, on Mercator's projection, by David H. Burr. It was published by J. Haven, 86 State St. in 1850. Scale [ca. 1:74,000,000]. The image inside the map neatline is georeferenced to the surface of the earth and fit to a non-standard 'Mercator' projection with the central meridian at 90 degrees west. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. "Showing the different routes to California, and distance by each, routes of different navigators, route of the contemplated Pacific R. Road, distances to China, Europe, & c." This map shows features such as drainage, cities and other human settlements, shoreline features, and more. Relief shown by abbreviated form lines. Includes historical notes, ship ill., tables of distances, "Nicaragua route" distances, and text on "Pacific Railroad." Insets: Map of the Nicaragua route -- Map of the proposed rail road from St. Louis to the bay of St. Francisco. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.