Flow of metal in constrained plane-strain extrusion forging- Part II

With many innovations in process technology, forging is establishing itself as a precision manufacturing process: as forging is used to produce complex shapes in difficult materials, it requires dies of complex configuration of high strength and of wear-resistant materials. Extensive research and development work is being undertaken, internationally, to analyse the stresses in forging dies and the flow of material in forged components. Identification of the location, size and shape of dead-metal zones is required for component design. Further, knowledge of the strain distribution in the flowing metal indicates the degree to which the component is being work hardened. Such information is helpful in the selection of process parameters such as dimensional allowances and interface lubrication, as well as in the determination of post-forging operations such as heat treatment and machining. In the presently reported work the effect of aperture width and initial specimen height on the strain distribution in the plane-strain extrusion forging of machined lead billets is observed: the distortion of grids inscribed on the face of the specimen gives the strain distribution. The stress-equilibrium approach is used to optimise a model of flow in extrusion forging, which model is found to be effective in estimating the size of the dead-metal zone. The work carried out so far indicates that the methodology of using the stress-equilibrium approach to develop models of flow in closed-die forging can be a useful tool in component, process and die design.

First record of Erysiphe aquilegiae on a host outside the Ranunculaceae

Erysiphe aquilegiae (Erysiphaceae) is found for the first time on Catharanthus roseus, in the Apocynaceae. This fungus is previously known only on the Ranunculaceae. A detailed description of this teleomorphic Australian specimen is given, along with its rDNA internal transcribed spacer sequence. © Australasian Plant Pathology Society 2006.

Bibulocystis gloriosa sp nov (Pucciniales) on Caesalpinia scortechinii in Queensland, with comments on Spumula caesalpiniae

A rust causing leaf spotting and distortion of twigs and branches of Caesalpinia scortechinii in Queensland is described as the new species Bibulocystis gloriosa. Uredinia and telia occur on spotted pinnules, and pycnia, aecial uredinia and telia on galled and twisted leaf rachides, twigs and branches. B. gloriosa is similar to Bibulocystis viennotii on Albizia granulosa in New Caledonia in having a macrocyclic life cycle with all spore states, and teliospores with two fertile cells and two cysts. It differs in having aecial urediniospores and urediniospores with uniformly thickened walls and several scattered germ pores, rather than the apically thickened walls and equatorial germ pores of B. viennotii. Teliospores in the two species are similar in size, but those of B. gloriosa have proportionally larger fertile cells and smaller cysts than in B. viennotii. To date, B. gloriosa is known from only two localities in south-eastern Queensland. Comparison with the type specimen of Spumula caesalpiniae on Caesalpinia nuga from Indonesia has shown that the two rusts are generically distinct.

Cyanide poisoning in cattle from Dysphania glomulifera (red crumbweed): Using the internet for rapid plant identification and diagnostic advice: Case Report

A 300-strong Angus-Brahman cattle herd near Springsure, central Queensland, was being fed Acacia shirleyi (lancewood) browse during drought and crossed a 5-hectare, previously burnt area with an almost pure growth of Dysphania glomulifera subspecies glomulifera (red crumbweed) on their way to drinking water. Forty cows died of cyanide poisoning over 2 days before further access to the plant was prevented. A digital image of a plant specimen made on a flat-bed scanner and transmitted by email was used to identify D glomulifera. Specific advice on the plant's poisonous properties and management of the case was then provided by email within 2 hours of an initial telephone call by the field veterinarian to the laboratory some 600 km away. The conventional method using physical transport of a pressed dried plant specimen to confirm the identification took 5 days. D glomulifera was identified in the rumen of one of two cows necropsied. The cyanogenic potential of D glomulifera measured 4 days after collection from the site of cattle deaths was 18,600 mg HCN/kg in dry matter. The lethal dose of D glomulifera for a 420 kg cow was estimated as 150 to 190 g wet weight. The plant also contained 4.8% KNO3 equivalent in dry matter, but nitrate-nitrite poisoning was not involved in the deaths.

Comparison of Culture and a Novel 5' Taq Nuclease Assay for Direct Detection of Campylobacter fetus subsp. venerealis in Clinical Specimens from Cattle

A Campylobacter fetus subsp. venerealis-specific 5' Taq nuclease PCR assay using a 3' minor groove binder-DNA probe (TaqMan MGB) was developed based on a subspecies-specific fragment of unknown identity (S. Hum, K. Quinn, J. Brunner, and S. L. On, Aust. Vet. J. 75:827-831, 1997). The assay specifically detected four C. fetus subsp. venerealis strains with no observed cross-reaction with C. fetus subsp. fetus-related Campylobacter species or other bovine venereal microflora. The 5' Taq nuclease assay detected approximately one single cell compared to 100 and 10 cells in the conventional PCR assay and 2,500 and 25,000 cells from selective culture from inoculated smegma and mucus, respectively. The respective detection limits following the enrichments from smegma and mucus were 5,000 and 50 cells/inoculum for the conventional PCR compared to 500 and 50 cells/inoculum for the 5' Taq nuclease assay. Field sampling confirmed the sensitivity and the specificity of the 5' Taq nuclease assay by detecting an additional 40 bulls that were not detected by culture. Urine-inoculated samples demonstrated comparable detection of C. fetus subsp. venerealis by both culture and the 5' Taq nuclease assay; however, urine was found to be less effective than smegma for bull sampling. Three infected bulls were tested repetitively to compare sampling tools, and the bull rasper proved to be the most suitable, as evidenced by the improved ease of specimen collection and the consistent detection of higher levels of C. fetus subsp. venerealis. The 5' Taq nuclease assay demonstrates a statistically significant association with culture (2 = 29.8; P < 0.001) and significant improvements for the detection of C. fetus subsp. venerealis-infected animals from crude clinical extracts following prolonged transport.

Podosphaera xanthii on Euryops chrysanthemoides in Australia

The anamorph of Podosphaera xanthii (Erysiphaceae) on Euryops chrysanthemoides is reported for the first time in Australia. A detailed description of the specimen is given, along with its rDNA internal transcribed spacer sequence.

Taxonomic notes on two powdery mildews: Phyllactinia chorisiae and Ovulariopsis wissadulae (Erysiphaceae: Phyllactinieae)

The powdery mildew Phyllactinia chorisiae has been considered conspecific with P. guttata. A re-examination of the type material of P. chorisiae and another specimen showed that this fungus, unlike P. guttata, has dimorphic conidia and its anamorph does not belong to the genus Ovulariopsis, which is the typical anamorph for Phyllactinia species. This suggests that P. chorisiae is morphologically distinct from P. guttata and should no longer be accepted as a synonym. Re-evaluation of type material of Oidiopsis wissadulae revealed that it has monomorphic conidia (mostly lemon-shaped) and hemiendophytic mycelium, a combination of characters that clearly places this fungus in the genus Ovulariopsis. Emended descriptions of P. chorisiae and Ovulariopsis wissadulae are presented.

Oidiopsis (Erysiphaceae) on Euphorbia spp. in Australia and Vanuatu

One specimen of powdery mildew on Euphorbia cyathophora from Vanuatu and 11 specimens on E. cyathophora, E. dentata, E. heterophylla and E. leucocephala from Australia were studied. All were shown to represent the Oidiopsis anamorph of Leveillula taurica, which is described. This is the first record of Oidiopsis in Vanuatu. E. leucocephala is a new host record for this powdery mildew.

Laboratoriohoitaja- ja sairaanhoitajakoulutuksen antamat valmiudet kliinisen mikrobiologian näytteenottoon

Tutkimuksen tavoitteena on ollut kuvata pian valmistuvien sairaanhoitaja- ja laboratoriohoitajaopiskelijoiden teoreettista työnhallintaa kliinisen mikrobiologian alaan kuuluvien potilasnäytteiden ottamisessa. Tutkimuksessa haluttiin selvittää, miten peruskoulutus ja työelämän harjoittelujaksot ovat vaikuttaneet näytteenottovalmiuksien syntymiseen sekä minkälainen käsitys valmistuvilla hoitajilla on omista mikrobiologisista näytteenottotaidoistaan. Syy tutkimuksen tekemiseen oli tarve arvioida ammatillisen koulutuksen tuloksellisuutta sekä hakea mikrobiologian opetusalueelta tutkimustietoa opetuksen kehittämiseen ja sisältöjen suuntaamiseen. Tutkimukseen osallistui 21 laboratoriohoitajaopiskelijaa ja 27 sairaanhoitajaopiskelijaa. Opiskelijat olivat viimeiseltä lukukaudelta ja valmistuivat keväällä 1998. Tiedonkeruumenetelmänä oli kyselylomake, jonka alkuosa koostui neljästä mikrobiologisesta näytteenottotilanteesta. Opiskelija vastasi toimintatapansa kertoen ja perustellen, miten hän ottaisi näytteet näissä tilanteissa. Vastaukset ryhmiteltiin käyttäen luokitteluun mukaeltua Solo-taksonomiaa. Koulutusta ja opiskelijan käsityksiä kartoittavat kysymykset olivat joko puolistrukturoituja tai avoimia. Laboratoriohoitajaopiskelijoiden tiedollinen työnhallinta sijoittuu tulosten perusteella tyydyttävän ja hyvän välimaastoon. Sairaanhoitajaopiskelijoiden tietotaso oli heikko ja osin hyvin heikko. Laboratoriohoitajaopiskelijat arvioivat koulutuksen antamia mikrobiologisen näytteenoton valmiuksia pääasiassa hyviksi tai tyydyttäviksi; sairaanhoitajaopiskelijat pitivät opetuksesta saamiaan valmiuksia heikkoina. Näytteenoton arvostusta pidettiin kaiken kaikkiaan matalana, ja tietoa laadukkaasta näytteenotosta arvioitiin puuttuvan työelämässä laajasti. Tutkimuksen perusteella näyttää siltä, ettei valmistuvilla sairaanhoitajilla ole tiedollisia ja taidollisia valmiuksia suoriutua edes perusnäytteenotosta niin, että saatu näyte edustaisi laadukkaasti potilaan tilaa näytteenottohetkellä. Näytteenotto on koko laboratoriotyön prosessin kriittisin vaihe. Jos näyte on otettu, säilytetty tai kuljetettu väärin, paraskaan analyysitekniikka ei pysty tuottamaan siitä potilaan hoitoa oikeaan suuntaan ohjaavaa tulosta. Kaikkien laboratorionäytteiden oton siirtäminen laboratoriohoitajille ja runsaan lisäkoulutuksen anto tälle ammattiryhmälle voisi tuottaa parannuksen vallitsevaan tilanteeseen. Avainsanat: ammattitaito, osaaminen, ammatillinen koulutus, kliinisen mikrobiologian näytteenotto, tiedollinen työnhallinta Keywords: occupational skills, competence, vocational education, collecting of specimen in clinical microbiology, conceptual mastery of work

Internal nitride formation during gas-phase thermal nitridation of titanium

Titanium nitride surface layers were prepared by gas-phase thermal nitridation of pure titanium in an ammonia atmosphere at 1373 K for different times. In addition to the surface nitride layer, nitride/hydride formation was observed in the bulk of the specimen. The cross-section of the specimen was characterized by various techniques such as optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, secondary ion mass spectrometry and nanomechanical testing, and the mechanism of formation of these phases is discussed.

Estimation of Cavitation Erosion with Incubation Periods and Material Properties

A detailed study of the normalized correlations between the incubation period tc and the properties of various materials tested in a rotating disk device indicates that, at very high intensities, the strength properties influence the duration of tc. The analysis of extensive data from other laboratories for cavitation and liquid impingement erosion also indicates that, while both energy and strength properties influence the duration of tc, the latter ones predominate for a majority of cases. A fatigue-type failure occurs during tc. For estimating the time required to pierce a metallic specimen in a rotating device a relationship tp = 160 tc0.44 is proposed. A detailed study of normalized correlations between erosion resistance (inverse of erosion rate) and tc values of different materials tested in the rotating disk shows that correlations are good. Analysis of data from eight other investigators clearly points out the validity and the usefulness of this type of prediction.

A review of Taenaris Hubner (Lepidoptera: Nymphalidae: Amathusiinae) in Queensland, together with first Australian records for T. myops kirschi Staudinger and Elymnias agondas melanippe Grose-Smith (Satyrinae).

Species of the amathusiine genus Taenaris Hubner known to occur in Australia, predominantly from Torres Strait, are reviewed and illustrated. T. myops kirschi Staudinger is recorded for the first time in Australia from four male specimens collected on Dauan Island, Torres Strait. A female specimen of the satyrine Elymnias agondas melanippe Grose-Smith also collected from Dauan Island represents the first record of this taxon from Australia. The high degree of variation observed in the external facies of Taenaris from Torres Strait and reliable taxonomic separation of female specimens are discussed. Taenaris-like forms of the papilionid, Papilio aegeus ormenus Guerin-Meneville and E. a. melanippe from Torres Strait and Dauan Island respectively are illustrated and reviewed. The form of P. a. ormenus from Torres Strait that is most similar to Taenaris spp. is identified as form ormenus Guerin-Meneville variety onesimus Hewitson.

Micromechanisms of damage in a hypereutectic Ti-6Al-4V-B alloy

The tensile stress–strain response and fracture in a hypereutectic Ti–6Al–4V–1.7B (weight percent) alloy were investigated by employing interrupted tensile tests combined with acoustic emission measurements, with the aim to identify the cause for the observed low ductility in this alloy. These tests were complemented with microscopy. The alloy contains TiB whiskers of different length scales, the majority of which include micro-whiskers ( 5–10 μm length) and a few primary-whiskers ( 200–300 μm length). Although the fracture of both types of whiskers occur during deformation, the former leads to a gradual decrease in the secant modulus whereas initiation of the latter leads to a drastic drop in the modulus along with failure of the specimen, limiting the ductility.

New distribution and lure records of Dacinae (Diptera: Tephritidae) from Queensland, Australia, and description of a new species of Dacus Fabricius

New distribution records for 42 species of fruit flies (Diptera: Tephritidae: Dacinae) in Queensland are presented, resulting from exotic fruit fly monitoring from 1996 to 2011. Summaries of previously known Australian distributions are provided. Fruit flies were collected at cue lure and methyl eugenol traps and reared from host fruit. No new distributions south of Townsville were recorded for the economic species Bactrocera frauenfeldi (Schiner, 1868), Bactrocera kraussi (Hardy, 1951) and Bactrocera musae (Tryon, 1927). Minor range extensions are noted for Bactrocera neohumeralis (Hardy, 1951) and Bactrocera tryoni (Froggatt, 1897). Bactrocera jarvisi (Tryon, 1927) is recorded being weakly attracted to cue lure in Queensland and the first lure record (one specimen from cue lure) is provided for Dacus (Mellesis) petioliforma (May, 1956). Taxonomic issues with Bactrocera melanothoracica Drew (1989) and Bactrocera unirufa Drew (1989) are discussed. Dacus (Neodacus) coenensis sp. n. is described and illustrated from Cape York Peninsula.

Phyllosticta species on orchids (Orchidaceae), introducing Phyllosticta speewahensis sp. nov. (Phyllostictaceae, Ascomycota) from northern Australia

Several species of Phyllosticta (syn. Guignardia) have been described from orchids worldwide. A new species, Phyllosticta speewahensis, is proposed for a specimen isolated from leaf spots on a hybrid Vanda orchid in northern Queensland, Australia. Phylogenetic analysis of the nrDNA internal transcribed spacer region (ITS) and partial translation elongation factor 1-alpha (TEF1) gene sequences showed that P. speewahensis is most closely related to P. hostae. The likelihood that orchids harbour further cryptic species of endophytic and pathogenic Phyllosticta species is discussed.