749 resultados para Gary Dessler
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It is commonly observed that complex fabricated structures subject tofatigue loading fail at the welded joints. Some problems can be corrected by proper detail design but fatigue performance can also be improved using post-weld improvement methods. In general, improvement methods can be divided into two main groups: weld geometry modification methods and residual stress modification methods. The former remove weld toe defects and/or reduce the stress concentrationwhile the latter introduce compressive stress fields in the area where fatigue cracks are likely to initiate. Ultrasonic impact treatment (UIT) is a novel post-weld treatment method that influences both the residual stress distribution andimproves the local geometry of the weld. The structural fatigue strength of non-load carrying attachments in the as-welded condition has been experimentally compared to the structural fatigue strength of ultrasonic impact treated welds. Longitudinal attachment specimens made of two thicknesses of steel S355 J0 have been tested for determining the efficiency of ultrasonic impacttreatment. Treated welds were found to have about 50% greater structural fatigue strength, when the slope of the S-N-curve is three. High mean stress fatigue testing based on the Ohta-method decreased the degree of weld improvement only 19%. This indicated that the method could be also applied for large fabricated structures operating under high reactive residual stresses equilibrated within the volume of the structure. The thickness of specimens has no significant effect tothe structural fatigue strength. The fatigue class difference between 5 mm and 8 mm specimen was only 8%. It was hypothesized that the UIT method added a significant crack initiation period to the total fatigue life of the welded joints. Crack initiation life was estimated by a local strain approach. Material parameters were defined using a modified Uniform Material Law developed in Germany. Finite element analysis and X-ray diffraction were used to define, respectively, the stress concentration and mean stress. The theoretical fatigue life was found to have good accuracy comparing to experimental fatigue tests.The predictive behaviour of the local strain approach combined with the uniformmaterial law was excellent for the joint types and conditions studied in this work.
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Tämä tutkimus on etnografinen kuvaus roolipeliharrastuksesta ja yritys määritellä tätä harrastusta. Tutkimuksen keskeinen aineisto on koottu teemakirjoituksin, joista suurin osa on saatu sähköpostin välityksellä eri puolelta Suomea. Paradigmaltaan tämä työ on lähinnä antropologista folkloristiikkaa, jossa ei keskitytä yksittäisiin perinnetuotteisiin, vaan tarkastelukohteena on roolipelaaminen kokonaisuutena, roolipelin käyttö ja merkitys harrastusyhteisössä. Roolipelaaminen on jotakin sellaista, mitä ei ole ollut olemassa ennen 1970-lukua ja mitä ei voi täysin palauttaa mihinkään muuhun toimintaan. Roolipeleissä, varsinkin sen pöytäpelimuodossa, ovat yleensä selvästi mukana pelaamisen tunnusmerkit, kun taas livepelaaminen voi muisttuttaa enemmän leikkimistä tai improvisoitua näyttelemistä. Roolipelaamisen eri muodoissa leikin ja pelin osuus vaihtelee, mutta useimmiten molemmat ovat läsnä. Tutkimuksen rakenteellisena viitekehyksenä olen käyttänyt Gary Alan Finen muotoilemaa roolipelaajan identiteetin kolmijakoa, joka perustuu Erving Goffmanin rooliteorioihin. Tämän mukaisesti olen tarkastellut roolipelaamista roolipelaajan kolmella minuustasolla, nimittäin henkilön, pelaajan ja pelihahmon tasoilla. Kussakin tasossa omia erityispiirteitään, mutta ne kaikki vaikuttavat jatkuvasti myös toinen toisiinsa. Henkilön ja pelaajan tasot ovat aina tavallaan läsnä pelihahmossa, sillä pelihahmo ei pysty kokonaan sulkemaan pois tietoja ympäröivästä maailmasta ja pelikontekstista. Toisaalta pelihahmon toiminta antaa yksilölle henkilökohtaisia kokemuksia ja elämyksiä tietyissä tilanteissa olemisesta, vaikka tämä oleminen onkin kuvitteellista. Roolipeliharrastus koostuu neljästä keskeisestä osa-alueesta, jotka ovat roolin vaihtaminen, pelimaailma, vuorovaikutus ja pelin sosiaalinen aspekti. Roolin vaihtamiseen kuuluvat sekä pelihahmo että samastumisprosessi. Pelimaailma on kokonaisuus, joka sisältää sekä pelin kuvitteellisen maailman että seikkailun, pelin ”juonen”. Vuorovaikutus on keskeinen osa roolipelin rakennetta. Siihen kuuluvat pelin viralliset säännöt, muut peliä varten sovitut säännöt ja ne säännöt, jotka lausumattomina ohjaavat toimintaa. Tähän kuuluu sekä pelihahmon että pelaajan toiminta pelin aikana. Tärkeä osa roolipeliharrastusta on myös roolipelaamisen sosiaalinen konteksti, mitä ilman tätä harrastusta ei voi kuvata ja ymmärtää täysin. Kaiken kaikkiaan roolipeli voidaan nähdä lähes karnevaalin tapaisena kokonaisuutena, jossa yhdessä irrottaudutaan tavallisesta arkisesta olotilasta ja siirrytään vähäksi aikaa toisenlaiseen maailmaan, jossa vallitsevat aivan erilaiset säännöt.
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OBJETIVO: Verificar o efeito da mudança no contraste do objeto, tempo de exposição e dose de radiação quando diferentes espessuras de filtração de molibdênio (Mo) e ródio (Rh) são empregadas em mamógrafos. MATERIAIS E MÉTODOS: Realizaram-se medidas da exposição na entrada da pele com uma câmara de ionização para diferentes espessuras para os filtros de Mo e Rh. Para determinar a dose glandular média foi utilizado simulador de BR12 (50% tecido adiposo e 50% tecido glandular) de diferentes espessuras (4 cm e 8 cm). Energias na faixa de 24 kVp a 34 kVp foram empregadas e filmes Kodak MinR 2000 foram utilizados. RESULTADOS: Os resultados evidenciaram dados de contraste do objeto, dose glandular e tempo de exposição para diferentes espessuras de filtros adicionais e diferentes tensões. Esses dados indicaram aumento nos valores de contraste do objeto e tempo de exposição, com o aumento da espessura dos filtros. A dose glandular apresentou comportamento com diferentes tendências para cada caso analisado. Equações foram definidas para possibilitar a estimativa do contraste do objeto, dose glandular e tempo de exposição para os casos estudados. CONCLUSÃO: Os resultados possibilitaram a estimativa de equações que auxiliam na verificação do comportamento do contraste do objeto e da dose glandular para simuladores com espessura de 4 cm e 8 cm e para os filtros de Rh e Mo. Dessa forma, torna-se possível estimar a figura de mérito (razão entre o contraste do objeto e a dose glandular), podendo auxiliar na análise da relação risco-benefício dos casos estudados.
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A giberela ou fusariose da espiga é, atualmente, uma das mais importantes doenças da cultura do trigo (Triticum aestivum). Epidemias severas têm sido observadas nos últimos anos em diversas regiões do mundo, promovendo perdas na produtividade e na qualidade dos grãos. No Brasil, a giberela alcançou o status de principal doença nas regiões tritícolas, principalmente no Sul do Brasil. A sua natureza esporádica está associada à dependência climática, sendo as mais severas epidemias observadas em anos com maior freqüência de chuvas, durante a fase de florescimento e enchimento de grãos. Poucas são as cultivares com resistência genética aceitável e essas normalmente falham em anos muito favoráveis a epidemias. Medidas de controle com fungicidas têm sido preconizadas, entretanto, a dificuldade reside no momento e na tecnologia de aplicação, para se obter resultados satisfatórios. O melhor entendimento dos fatores que influenciam a dinâmica da doença pode auxiliar no manejo da cultura visando a minimizar os riscos de epidemias. Aspectos como aerobiologia e tipo de inóculo, distribuição espacial e gradiente espacial da doença podem contribuir no conhecimento da associação e a importância de fontes de inóculo local ou distante ao campo. Recentemente, uma grande atenção tem sido dada ao desenvolvimento de modelos de previsão ou de risco de giberela. Tais modelos podem auxiliar na tomada de decisão no acionamento de medidas de controle bem como alertar níveis epidêmicos da doença em uma determinada região, ou mesmo quanto à alta contaminação do trigo com micotoxinas de Fusarium spp.
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Ilmavoimien taistelunjohtoalaa on tutkittu hyvin vähän. Alan tietoturvatasot ja asioiden tuottaminen kirjallisiksi ohjeiksi eivät ole vielä sillä tasolla, jolla niiden voisi toivoa olevan. Hiljaista tietoa on paljon. Menetelmävalinnan perusteella tutkimuksen tavoitteena oli luoda alan julkista teoriaa. Tutkimusstrategisina valintoina olivat laadulliset tapaustutkimus ja nelivaiheinen Critical Decision Method. Tutkimuksen tarkoituksena oli hahmottaa vaatimuksia ilmavoimien taistelunjohtajan päätöksenteon pohjaksi sekä luoda kuvaus päätöksentekoprosessista tarkastellussa tapauksessa. Päätutkimuskysymyksenä oli selvittää, millaista päätöksentekotapaa taistelunjohtaja käyttää. Tutkimus rajattiin rationaalisen ja naturalistisen päätöksenteon esiintyvyyksien vertailuun valitussa taistelunjohtotehtävässä. Alakysymyksinä selvitettiin, millaisia tunnistettavia vaatimuksia ja vihjeitä ilmenee taistelunjohtajien päätöksentekoon liittyen sekä millainen on taistelunjohtajan tilannetietoisuus tarkastellussa tapauksessa ja miten tilannetietoisuutta voidaan jälleenrakentaa tukemaan päätöksentekoa sen romahdettua. Tutkimuksessa tarkasteltiin päätöksentekoa tapauksessa observoidun kokeneen yksittäisen taistelunjohtajan haastattelujen ja tilannetietoisuuden subjektiivisten arvioiden perusteella. Tilannetietoisuutta tarkasteltiin Mica Endsleyn kolmen tilannetietoisuuden tason ja Robert Taylorin Situational Awareness Rating Techniquen kymmenen ulottuvuuden perusteella. Tutkimuksen tulokset osoittivat ilmavoimien taistelunjohtajien päätöksenteon perustuvan Gary Kleinin kehittämään tilanteen tunnistavaan The Recognition-Primed Decision -malliin. Siinä taistelunjohtaja muodostaa mentaalisen mallin ja testaa ideologian toimivuuden mielessään ennen mahdollisesti toimeenpanevaa päätöksentekoa. Toimintaa ohjaa vahvasti koulutus. Samalla taistelunjohtaja rakentaa jatkuvasti tilannetietoisuuttaan, joka nousi merkittävimpänä tekijänä esiin ilmentyen intuitiivisen päätöksenteon perustaksi. Tulokset osoittivat, että taistelunjohtajan päätöksenteko perustuu naturalistiseen päätöksentekoon, koska tehtävän hektisyyden takia ei ole aikaa vaihtoehtojen laajalle vertailulle. Tehtäväkentän laajuuden takia taistelunjohtajan päätöksenteon vaatimuksiksi ilmeni useita elementtejä. Huolimatta tehtävänaikaisesta aikapaineesta, taistelunjohtajan tilannetietoisuus oli tarkastellussa tapauksessa jatkuvasti korkealla tasolla. Tutkimuksen johtopäätöksenä voidaan todeta, että taistelunjohtajien koulutusjärjestelmä on kattava ja se toimii. Päätöksenteon koulutuksessa on kuitenkin kiinnitettävä huomiota kommunikaation merkitykseen. Siinä tilanteen tunnistamiseen johtavat vihjeet olivat epäselviä. Saatuja tuloksia voidaan hyödyntää ilmavoimien taistelunjohtajien ja taistelunjohto-opettajien koulutuksessa, valinnoissa sekä alan ohjeistusten luomisessa ja kehittämisessä.
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Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014
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Correspondence from 1978 between Terry O'Malley and Gary Reinblatt, Assistant Vice-President, McDonald's Restaurants of Canada Ltd. regarding McDonald's account.
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Correspondence from 1978 between Terry O'Malley and Gary Reinblatt, Assistant Vice-President, McDonald's Restaurants of Canada Ltd. regarding McDonald's account.
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Pictured here from left to right: Back Row - Les Korchok (Coach), Ken Cripps, Mike McGinnis, Bill Butler, Tim McKillop, Gary Jellum, Fred Kovacs (Manager). Front Row - Jim Leach, Wally Dick, Bob Tatti, Paul Zutautas, Tom Kearney (Trainer). Kneeling - Dave Luff, Dave Brent. Missing - Bill Levesque.
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Back Row: J.B. Owens, Ross Smith (Head Coach), Adam Frost, Derrick Harwood, Dave DeRose, Bill Arniel, Danny Mazor, Alan Ross, Randy McKeller, Pete McDougall, Ray D'Archi, Kelvin Oda, Mark Pelletier, Eric Thompson, Marty Houston, Ken White (Asst. Coach) Front Row: Peter Love, Chris Peskett, Duff Porteous, Bart Ward, Dave Sohmer, Gary Gautier, Ken Murray, Dave Tamowski, Steve Shaughnessy, Jeff Wood Absent: Alfred Esmaily, Luc Gignac, Fred Kovacs, Andrew Norman
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One component of successful parenting is related to efficiency in foraging behaviour. The relationships among chick feeding, the size and type of food package, and length of parental foraging trips has not been well studied in seabirds. In addition, relatively few data have been collected on the activities of seabirds when foraging away from the nest site. The objectives of this study were: (1) to contrast productivity, feeding rate, and attendance patterns of individuals carrying a novel transmitter with a control group of birds; (2) to use radio-telemetry to assess the variability in foraging locations within and between individual male Common Terns; (3) to determine the seasonal variation in chick diet; (4) to determine for each transmittered bird, the relationships among the foraging patterns, parental behaviour, and seasonal reproductive success. The study took place over two years (1990-91) on a concrete breakwater 1 km offshore on Lake Erie near Port Colbome, Ontario. Ten pairs of terns in 1990 and 12 pairs in 1991 were radio-tracked by boat or car during the chick rearing stage. Concurrent behavioural observations documented the time each sex spent foraging or at the nest. The frequency and prey species composition of feeds to chicks were also recorded. The transmitters had negligible effects on the feeding frequency and brood attendance patterns of transmitter carrying birds. Peak nesting transmittered birds in 1990 and 1991 exhibited some inter-individual variability in foraging locations, however intraindividual variability was low. Birds foraged primarily to the west and northwest of the colony. Late nesters exhibited greater inter-individual variability, however intra-individual variability remained low for most birds. Neither group demonstrated sufficient variability to support the regular use of this colony as an "information centre". Individual transmittered birds had unique and predictable foraging patterns, and corresponding differences in feeding frequencies and brood attendance patterns, yet productivity was essentially equal between nests due to the impact and importance of stochastic events. Individuals that were recaptured in 1991 exhibited very similar foraging patterns to 1990, suggesting littie variability between years. Conservation of foraging patterns between years may have potential implications for mate choice decisions in future breeding seasons. Prey species delivered to chicks differed between morning and evening for peak and late nesters in 1990, but not 1991. Peak nesters in 1990 fed significantiy more Rainbow Smelt fOsmerus mordM) than Emerald Shiner (Notropis atherinoidesV this trend was reversed for late nesters who also fed large numbers of unidentified larval fish. No significant differences were found in 1991. Seasonal changes in prey species delivered to chicks is believed to be attributable to the temperature tolerances of the smelt and shiners, and the presence of large schools of larval fish during the late nesting season.
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We study the phonon dispersion, cohesive and thermal properties of raxe gas solids Ne, Ar, Kr, and Xe, using a variety of potentials obtained from different approaches; such as, fitting to crystal properties, purely ab initio calculations for molecules and dimers or ab initio calculations for solid crystalline phase, a combination of ab initio calculations and fitting to either gas phase data or sohd state properties. We explore whether potentials derived with a certain approaxih have any obvious benefit over the others in reproducing the solid state properties. In particular, we study phonon dispersion, isothermal ajid adiabatic bulk moduli, thermal expansion, and elastic (shear) constants as a function of temperatiue. Anharmonic effects on thermal expansion, specific heat, and bulk moduli have been studied using A^ perturbation theory in the high temperature limit using the neaxest-neighbor central force (nncf) model as developed by Shukla and MacDonald [4]. In our study, we find that potentials based on fitting to the crystal properties have some advantage, particularly for Kr and Xe, in terms of reproducing the thermodynamic properties over an extended range of temperatiures, but agreement with the phonon frequencies with the measured values is not guaranteed. For the lighter element Ne, the LJ potential which is based on fitting to the gas phase data produces best results for the thermodynamic properties; however, the Eggenberger potential for Ne, where the potential is based on combining ab initio quantum chemical calculations and molecular dynamics simulations, produces results that have better agreement with the measured dispersion, and elastic (shear) values. For At, the Morse-type potential, which is based on M0ller-Plesset perturbation theory to fourth order (MP4) ab initio calculations, yields the best results for the thermodynamic properties, elastic (shear) constants, and the phonon dispersion curves.
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The Island Lake greenstone belt is one of the major Archean supracrustal exposures in the northwestern part of the Superior Province of the Canadian Shield. This belt is subdivided into two units: 1) a lower sequence characterised by pillowed to massive, locally pyroclastic, basalt to andesite with a thin central zone of felsic derivatives, all of which are interbedded with and overlain by thick sequences of turbidite facies rock; 2) the upper unit which consists of thick stratified conglomerate overlain by thickly bedded arkose and feldspathic greywacke. Reconnaissance sampling traverses were completed across both the strike of the belt and along its margins with adjacent granitoids. Most of the belt is within the greenschist metamorphic f acies with amphibolite facies occurring in certain areas near t he margins. A post-tectonic, low pressure thermal event may be responsible for the development of a unit of cordierite schi s t which stretches southeastwards from the east end of Cochrane Bay. Volcanism is cyclical in nature changing from tholeiitic to calc-alkaline. There is a general progression in the character of the lavas from mafic t o felsic with stratigraphic height. Chemica l d a ta sugges t that h i gh level fractionation of a mantle- derived ' dry' magma i s t he s ource of the thole i iti c lavas. Contamination of this magma with 'we t' sia l and subsequent fractionation may be r esponsi b l e for the calcalkaline phases .Observations of stratigraphic relationships (in particular the contact between the supracrustals and the granitoids) coupled with the metamorphic and chemical studies, allow the construction of a preliminary model for the evolution of the Island Lake greenstone belt. The following sequential development is suggested: 1) a platform stage characterised by the subaqueous effusion of mafic to intermediate lavas of alternating tholeiitic and calc-alkaline affinities; 2) an edifice stage marked by the eruption of felsic calc-alkaline rocks; 3) an erosional stage characterised by the deposit~on of thick sequences of turbidite facies rocks; 4) the impingement of granitic masses into the margins of the greenstone belt, which was probably related to a downward warping of the supracrustal pilei 5) the erosion of sialic massifs surrounding and within the greenstone belt and of early supracrustal piles, to give the clastic upper unit.
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Nuclear magnetic resonance spectroscopy has been used to study donor-acceptor complexes of boron trifluoride with several ureas, tetramethylthiourea, tetramethylselenourea, and tetramethylquanidine as well as adducts of tetramethyl- -urea with BF2Cl, BFC1 2 , and BC1 3 - A large number of mixed tetrahaloborate ions, including some of the ternary ones such as BF2CIBr-,have been obtained by ligand exchange reactions and studied by NMR techniques. The bonding in these ions is of the same inherent interest as the bonding in the isoelectronic tetrahalomethanes which have been the subject of many detailed studies and have been involved in a controversy concerning the existence of and the nature of "fluorine hyperconjugation" or C-F P1T- Pn bonding_ Ligand exchange reactions also gave rise to the difluoroboron cation, (TMU)20BF2+o The difluoroboron cation has been observed in solutions of TMU-BF3 , and has been proposed as a possible intermediate for fluorine exchange reactions in BF3 adducts.