The effect of microstructure on mechanical properties of HVOF sprayed WC-CoCr composite coatings

This study aims for deeper understanding of the composition and phase changes occurring during HVOF spraying of the powder to WC-CoCr coatings. Also, the effect of lamellar microstructure on the mechanical properties is studied. Compositional and microstructural features are studied by means of X-ray diffraction, XRF, FE-SEM and TEM (EDX, EELS). Mechanical properties are mainly studied by different instrumented indentation and nanoindentation techniques. The use of two new fracture parameters, complementing the fracture toughness value of the coating, are proposed and examined. Higher load range indentations are used to measure cross-sectional and surface hardness, elastic modulus and fracture toughness of the coatings. Mechanical properties of individual phases are studied by nanoindentation. To our knowledge this is the first time that the mechanical properties of this amorphous/nanocrystalline matrix are studied. ICP (In-situ Coating Property) sensor, developed for quality control and residual stress evaluation, is also used to measure the elastic modulus and coefficient of thermal expansion (CTE) of the coatings. Abrasion wear resistance of the coatings are studied according to standard ASTM G 65D. Because of the brittle nature of HVOF coatings, the main focus of this study is in the effects of coating microstructure on fracture toughness, and on crack initiation and propagation resistance. It is shown that even when two similar coatings have equal indentation fracture toughness values, the critical crack initiation loads may be very different. This new parameter is expected to be extremely useful in the evaluation of the coating performance under loading conditions

Collaboration in the Semantic Grid: a Basis for e-Learning

The CoAKTinG project aims to advance the state of the art in collaborative mediated spaces for the Semantic Grid. This paper presents an overview of the hypertext and knowledge based tools which have been deployed to augment existing collaborative environments, and the ontology which is used to exchange structure, promote enhanced process tracking, and aid navigation of resources before, after, and while a collaboration occurs. While the primary focus of the project has been supporting e-Science, this paper also explores the similarities and application of CoAKTinG technologies as part of a human-centred design approach to e-Learning

Evaluating the impact of pyrethroid insecticide resistance on reproductive fitness in Sitobion avenae

Resistance to insecticides used to control pests is an issue of increasing concern for agriculture. The grain aphid, Sitobion avenae, is a pest of cereals and grasses worldwide, and one of growing concern due to the evolution of resistance to certain insecticides. Resistance confers benefits to insects by enabling them to survive exposure to insecticide compounds; however, the mutations conferring resistance may also penalise the insect in pesticide-free environments due to fitness costs associated with the new phenotype. Here we tested the hypothesis of a reproductive penalty linked to the knockdown resistance mutation (kdr) to pyrethroid insecticides. The mutation occurs predominantly in a single SA3 clone. To date, only heterozygous-resistant forms (kdr-SR) have been detected in populations in Ireland and the UK, and this suggests that a fitness penalty may preclude the formation of both male and female heterozygous-resistant sexual forms. By designing an experiment which included a resistant and a non-resistant clone, we were able to simulate reduced daylight and temperature conditions which, in nature, trigger sexual reproduction and therefore study the responses of each clone. This allowed us to detect the switch from asexual females to sexual females and males and report on the conditions associated with the production of sexual forms. The results showed that both aphid clones were able to produce sexual forms with no difference in the onset of sexual reproduction, although reproductive strategies differed between clones. The later onset of male forms in the SA3 clone may decrease the likelihood of mating interactions to create fully resistant (kdr-RR) genotypes and this may constitute a fitness penalty due to pyrethroid resistance

Comparing international coverage of 9/11 : towards an interdisciplinary explanation of the construction of news

This article presents an interdisciplinary model attempting to explain how news is constructed by relying on the contributions of different fields of study: News Sociology, Political Communications, International Communications, International Relations. It is a first step towards developing a holistic theoretical approach to what shapes the news, which bridges current micro to macro approaches. More precisely the model explains news variation across different media organization and countries by focusing on the different way the sense of newsworthiness of journalists is affected by three main variables: national interest, national journalistic culture, and editorial policy of each media organization. The model is developed on the basis of an investigation into what shaped the media coverage of 9/11 in eight elite newspapers across the US, France, Italy and Pakistan

Direct and indirect mechanisms behind successful biomanipulation

Lake Vesijärvi is a relatively large (length 25 km; total area 110 km2), shallow (mean depth 6 m), but stratified lake in southern Finland. The Enonselkä basin (26 km2), surrounded by the city of Lahti, received its sewage effluent, and changed from a clear water basin with flourishing fisheries from the 1940–50s to one of the most eutrophic lake systems in Finland thereafter. In 1976, the sewage effluent was diverted, resulting in a temporary recovery of water quality. However, in the 1980s, massive surface scums of cyanobacteria degraded the water quality and arrested the recovery of the lake. A restoration strategy providing an ecologically sound basis for the management of the lake was initiated in 1987. This strategy involved biomanipulation (mass removal of coarse fish) together with conventional pollution control measures on discharges to the lake. Biomanipulation was chosen instead of much more expensive chemical and/or technical methods, such as chemical treatment or dredging of the profundal sediment. The large-scale biomanipulation trial was carried out in the Enonselkä basin during 1989–93. Following the mass removal of coarse fish (1000 metric tons of fish; mainly roach and smelt), the biomass of cyanobacteria collapsed concomitantly with a decline of total phosphorus concentration from 45 to 35 mg P m3, and with an increase of Secchi depth from 1 m to 3.5 m. These observed improvements in the water quality were matched with a large decline in roach-mediated phosphorus movement from littoral to pelagial, from 100 mg P m2 in 1989 t

Planck pre-launch status: Low Frequency Instrument calibration and expected scientific performance

We give the calibration and scientific performance parameters of the Planck Low Frequency Instrument (LFI) measured during the ground cryogenic test campaign. These parameters characterise the instrument response and constitute our best pre-launch knowledge of the LFI scientific performance. The LFI shows excellent $1/f$ stability and rejection of instrumental systematic effects; measured noise performance shows that LFI is the most sensitive instrument of its kind. The set of measured calibration parameters will be updated during flight operations through the end of the mission.Comment: Accepted for publications in Astronomy and Astrophysics. Astronomy & Astrophysics, 2010 (acceptance date: 12 Jan 2010

DNA copy number changes in young gastric cancer patients with special reference to chromosome 19

Only a few cytogenetic and genetic studies have been performed in gastric cancer patients in young age groups. In the present study we used the comparative genomic hybridisation (CGH) method to characterise frequent DNA copy number changes in 22 gastric cancer patients of 45 years or younger and three gastric cancer cell lines established from patients younger than 45 years. Analysis of DNA copy number changes revealed frequent DNA copy number increases at chromosomes 17q (52%), 19q (68%) and 20q (64%). To confirm the CGH results and to characterise the amplicon region on the most frequently amplified chromosome, chromosome 19, we carried out fluorescence in situ hybridisation (FISH) analysis and Southern blot analysis. Fluorescence in situ hybridisation with the bacterial artificial chromosome (BAC) clone mapped to 19q12 indicated a copy number increase in all eight tumour specimens studied. Southern blot analysis of six tumour specimens and three tumour cell lines, with five probes mapped to the 19q12-13.2 region, suggested cyclin E to be one of the candidate target genes in the 19q region for gastric cancer tumorigenesis. Cyclin E protein overexpression was verified in tumours with amplification on chromosome 19. Further studies are required to investigate the biological and clinical significance of 19q amplicon and cyclin E upregulation in gastric cancer of young patient

Aorttaläppäahtauman katetrihoito oli turvallista myös keskussairaaloissa

Lähtökohdat : Vuoden 2018 alussa voimaan tullut keskittämisasetus kielsi vaikean aorttaläppäahtauman hoitamisen TAVI-toimenpiteellä (transcatheter aortic valve implantation) sairaaloissa, joissa ei ole avosydänkirurgiaa. Ennen asetuksen voimaantuloa TAVI- oimenpiteet ehdittiin aloittaa neljässä keskussairaalassa. Menetelmät : Vuosina 2015–2018 TAVI-toimenpide tehtiin keskussairaalassa 174 potilaalle yhdellä itsestään laajentuvalla läppätyypillä. Yhtä lukuun ottamatta kaikki toimenpiteet suoritettiin paikallispuudutuksessa nivusvaltimon kautta sydänangiosalissa. Tulokset : Potilaiden keski-ikä oli 83 vuotta. Potilaat olivat hyvin oireisia; 80 %:lla oli vähintään NYHA (New York Heart Association) -luokan 3 oireisto. Hengenahdistusoireisto parani seurannassa 84 %:lla potilaista. 97 %:lla ei todettu merkittää läppäproteesin vierusvuotoa. Kirurgiaa vaatineita verisuonikomplikaatioita sattui kolmelle (1,7 %) potilaalle. Kaksi potilasta kuoli toimenpiteeseen (1,1 %). Viisi (2,9 %) potilasta kuoli 30 vuorokauden aikana ja yhdeksän (5,2 %) 12 kuukauteen mennessä. Päätelmät : Keskussairaaloissa ilman avosydänkirurgista valmiutta tehdyt TAVI-toimenpiteet olivat turvallisia. Tutkimuksen perusteella TAVI-toimenpiteiden keskittämisellä viiteen yliopistosairaalaan ei saavuteta hyötyä potilasturvallisuuden kannaltaPeer reviewe

Aorttaläppäahtauman katetrihoito oli turvallista myös keskussairaaloissa

Vertaisarvioitu.Lähtökohdat : Vuoden 2018 alussa voimaan tullut keskittämisasetus kielsi vaikean aorttaläppäahtauman hoitamisen TAVI-toimenpiteellä (transcatheter aortic valve implantation) sairaaloissa, joissa ei ole avosydänkirurgiaa. Ennen asetuksen voimaantuloa TAVI- oimenpiteet ehdittiin aloittaa neljässä keskussairaalassa. Menetelmät : Vuosina 2015–2018 TAVI-toimenpide tehtiin keskussairaalassa 174 potilaalle yhdellä itsestään laajentuvalla läppätyypillä. Yhtä lukuun ottamatta kaikki toimenpiteet suoritettiin paikallispuudutuksessa nivusvaltimon kautta sydänangiosalissa. Tulokset : Potilaiden keski-ikä oli 83 vuotta. Potilaat olivat hyvin oireisia; 80 %:lla oli vähintään NYHA (New York Heart Association) -luokan 3 oireisto. Hengenahdistusoireisto parani seurannassa 84 %:lla potilaista. 97 %:lla ei todettu merkittää läppäproteesin vierusvuotoa. Kirurgiaa vaatineita verisuonikomplikaatioita sattui kolmelle (1,7 %) potilaalle. Kaksi potilasta kuoli toimenpiteeseen (1,1 %). Viisi (2,9 %) potilasta kuoli 30 vuorokauden aikana ja yhdeksän (5,2 %) 12 kuukauteen mennessä. Päätelmät : Keskussairaaloissa ilman avosydänkirurgista valmiutta tehdyt TAVI-toimenpiteet olivat turvallisia. Tutkimuksen perusteella TAVI-toimenpiteiden keskittämisellä viiteen yliopistosairaalaan ei saavuteta hyötyä potilasturvallisuuden kannaltaPeer reviewe

Planck pre-launch status: calibration of the Low Frequency Instrument flight model radiometers

The Low Frequency Instrument (LFI) on-board the ESA Planck satellite carries eleven radiometer subsystems, called Radiometer Chain Assemblies (RCAs), each composed of a pair of pseudo-correlation receivers. We describe the on-ground calibration campaign performed to qualify the flight model RCAs and to measure their pre-launch performances. Each RCA was calibrated in a dedicated flight-like cryogenic environment with the radiometer front-end cooled to 20K and the back-end at 300K, and with an external input load cooled to 4K. A matched load simulating a blackbody at different temperatures was placed in front of the sky horn to derive basic radiometer properties such as noise temperature, gain, and noise performance, e.g. 1/f noise. The spectral response of each detector was measured as was their susceptibility to thermal variation. All eleven LFI RCAs were calibrated. Instrumental parameters measured in these tests, such as noise temperature, bandwidth, radiometer isolation, and linearity, provide essential inputs to the Planck-LFI data analysis.Comment: 15 pages, 18 figures. Accepted for publication in Astronomy and Astrophysic