3,936 research outputs found
An investigation into damage initiation and propagation in carbon fibre reinforced plastics
No full textIn this investigation into the initiation and propagation of damage in CFRP materials, a method was first established whereby damage could be induced, during flexure, at the centre of thin plate-like cantilever specimens. An acceptable clamping shape was found using 3-D Finite Element modelling. This technique was also useful in deducing the types of stress that were responsible for delamination, and in assessing the fatigue resistance of various layups. Results were confirmed by Thermography and Scanning Electron Microscope results. Experimental results indicated that damage initiation during flexural fatigue occurred earlier for higher surface strains, and that subsequent delamination affected damping, natural frequency and static stiffness of specimens. There was also shown to be the possibility of the existence of a fatigue strain limit for the material. Experimental and theoretical work was extended to examine the condition of in-plane stress with superimposed dynamic excitation. Here, difficulty was experienced in designing experiments complementary to F.E. models. However, results predicted the direction of damage propagation and that the presence of in-plane stresses could be detrimental to fatigue life. A more refined F.E. model in which delamination could be opened between desired layers, indicated that shear stresses were greater the further the delamination was sited from the neutral plane. Since failure during experiments always occurred between the same two layers, this suggested that high shear stresses had a stronger influence upon crack initiation than small defects which might have occurred anywhere throughout the thickness. Acoustic Emission work demonstrated the existence of 'micromechanical' damage, which was suspected to be fibre breakage. At a constant amplitude of dynamic flexural loading, emissions occurred initially, but after a certain time ceased almost completely. A hypothesis was suggested to account for such mechanisms, and their possible influence upon delamination
A review of the Indo-Australian subgenus Parasinodacus Drew and Romig of 'Bactrocera Macquart' (Diptera: Tephritidae: Dacinae)
No full textThe 'Bactrocera' Macquart subgenus 'Parasinodacus' Drew and Romig is reviewed and 19 species recognised, including six transferred from other subgenera: 'B. (P.) absoluta' (Walker) and 'B. (P.) atypica' White and Evenhuis (newly transferred from 'Asiadacus' Perkins), 'B. (P.) abdopallescens' (Drew) and 'B. (P.) perpusilla' (Drew) (formally transferred from 'Sinodacus' Zia), 'B. (P.) hoedi' White and 'B. (P.) pura' White (newly transferred from 'Zeugodacus' Hendel). A key to species is included.Full Tex
A review of the subgenus Javadacus Hardy of Bactrocera Macquart (Diptera: Tephritidae: Dacinae)
No full textThe Bactrocera Macquart subgenus Javadacus Hardy is reviewed and five SE Asian species recognised. Four additional species from SE Asia and Australia, previously included in Javadacus, are transferred to subgenus Bactrocera, with B. unirufa Drew placed as a new synonym of B. melanothoracica Drew. Based on its type species, subgenus Javadacus is included in the Zeugodacus groip of subgenera. A key to species is included.Full Tex
A review of the subgenera Apodacus Perkins, Hemizeugodacus Hardy, Neozeugodacus May, stat. rev., Semicallantra Drew and Tetradacus Miyake of Bactrocera Macquart (Diptera: Tephritidae: Dacinae)
No full textThe Indo-Australian subgenera Apodacus Perkins (= Heterodaculus Hardy, syn. n.), Hemizeugodacus Hardy, Neozeugodacus May, stat rev., Semicallantra Drew and Tetradacus Miyakc of Bactrocera Macquart are reviewed. Bactrocera (Tetradacus) superba Drew & Romig is newly transferred from subgenus Semicallantra, B. (.Asiadacus) fuscans (Wang) is removed from synonymy with B. (Tetradacus) brachycera (Bezzi) and B. (Bactrocera) fuscalata Drew is transferred from subgenus Heterodaculus. The subgeneric placement of B. (Zeugodacus) arisanica (Shiraki) is discussed. Keys to the 23 included species are provided.Full Tex
A review of the subgenus 'Bulladacus' drew and hancock of 'bactrocera' Macquart (Diptera: Tephritidae: Dacinae), with description of two new species from Papua New Guinea
No full textThe 'Bactrocera' Macquart subgenus 'Bulladacus' Drew and Hancock is reviewed. 'Bactrocera (Bulladacus) trilobata' sp. n. and 'Bactrocera (Bulladacus) wanangiae' sp. n. are described from Papua New Guinea. 'Bactrocera obtrullata' White and Evenhuis, 1999, is placed as a new synonym of 'B. diaphana' (Hering, 1953); both were described from Papua Province in eastern Indonesia. The Solomon Islands species 'B. unipunctata' (Malloch) is transferred from subgenus 'Bactrocera' to 'Bulladacus'. Males of 'B. aceromata' White and Evenhuis are newly described. Records of 'B. mcgregori' (Bezzi) from Singapore, West Malaysia and the Andaman and Nicobar Islands are regarded as misidentifications of 'B. cinnabaria' Drew and Romig. 'Bactrocera pacificae' Drew and Romig is newly recorded from Papua New Guinea. A key to the 20 known species is included.Griffith Sciences, School of Natural SciencesFull Tex
A review of the Indo-Australian subgenera 'Heminotodacus' drew, 'Paradacus' perkins and 'Perkinsidacus' subgen. n. of 'Bactrocera' macquart (Diptera: Tephritidae: Dacinae)
No full textThe Indo-Australian subgenera 'Heminotodacus' Drew (1 species) and 'Paradacus' Perkins (7 species) of 'Bactrocera' Macquart are reviewed and a new subgenus, 'Perkinsidacus' subgen. n., is proposed for two Australasian species: 'Bactrocera banneri' White from Morotai, northern Moluccas and 'B. coracinus' (Drew) [type species] from Papua New Guinea. These three subgenera belong in the 'Zeugodacus' group of subgenera and are distinguished by the presence of 2 pairs of scutellar setae and no medial yellow vitta on the scutum. A key to the ten species placed in these three subgenera is included.Full Tex
Drew Lopenzina, 40th Annual ODU Literary Festival
No full textDrew Lopenzina hails from the Berkshires of Western Massachusetts and teaches Early American and Native American literatures at Old Dominion University in Norfolk. His second book, Through an Indian\u27s Looking Glass (University of Massachusetts Press), is a cultural biography of the Pequot writer, activist and minister William Apess, the first Native American to write and publish his own book length treatises and memoirs in the 1820\u27s and 30\u27s. Praise by Barry O\u27Connell states that Lopenzina brings Apess nearly fully to life, which no one else, among many scholars, has. I know of no better reader of Apess\u27s own writing. Lopenzina is also the author of Red Ink: Native Americans Picking up the Pen in the Colonial Period. His essays appear in the journals American Literature, American Quarterly, Studies in American Indian Literature, Native American and Indigenous Studies and others
A Review of the Subgenus Austrodacus Perkins of Bactrocera Macquart (Diptera: Tephritidae: Dacinae)
No full textThe Bactrocera Macquart subgenus 'Austrodacus' Perkins is reviewed and 5 species recorded from Australia and New Guinea are included: 'B. abdoaurantiaca' Drew, B. alampeta Drew, 'B. atrisetosa' (Perkins), B. cucumis (French) and 'B. papuaensis' (Malloch), comb. n. (= 'unichromata' Drew, syn. n.). Subgenus 'Hemiparatridacus' Drew is placed as a new synonym of subgenus 'Austrodacus and its sole species, 'B. abdoaurantiaca', is transferred, while 'B. alampeta', 'B. atrisetosa' and 'B. papuaensis' are transferred to 'Austrodacus' from subgenus 'Paratridacus' Shiraki. A fourth Papua New Guinean species previously included in 'Paratridacus, B. mesonotaitha' Drew, is transferred to subgenus 'Zeugodacus' Hendel as a close ally of 'B. (Z.) sandaricina' Drew.Full Tex
A review of the Indo-Australian subgenus 'Paratridacus Shiraki' of 'Bactrocera Macquart' (Diptera: Tephritidae: Dacinae)
No full textThis is the eighth in a series of papers reviewing the subgenera of the economically important fruit fly genus Bactrocera Macquart, made possible by the revisions of Australasian and Southeast Asian species by Drew (1989) and Drew and Romig (2013) respectively. This paper deals with subgenera Hemisurstylus Drew and Paratridacus Shiraki, which are considered here to be synonymous and to contain six described species. Paratridacus is distinguished by a broadly rounded posterior surstylus lobe and absence of the pecten on abdominal tergite III in males, the presence of 2 pairs of scutellar setae and elongate lateral postsutural yellow vittae. It is distributed from eastern and southern Asia to Papua New Guinea and Australia and is placed in the Melanodacus group of subgenera as defined by Drew (1989). Known host plants are Garcinia spp (Clusiaceae) and no species has been attracted to known male lures. Five additional species from Papua New Guinea and Maluku, included by Drew (1989) or Drew and Romig (2013, 2016), were transferred to other subgenera by Hancock and Drew (2016, 2017b).Full Tex
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