127,208 research outputs found
Thermo-mechanical analysis of wire and arc additive layer manufacturing process on large multi-layer parts
No full textWire and Arc Additive Layer Manufacturing (WAALM) is gaining increasing
popularity as the process allows the production of large custom-made metal
workpieces with high deposition rates. The high power input of the welding
process, causes significant residual stress and distortion of the workpiece.
This paper describes the thermo-mechanical behaviour of the multi-layer wall
structure made by the WAALM process. A 3D thermo-elastic–plastic transient model
and a model based on an advanced steady-state thermal analysis are employed in
this study. This modelling approach shows a significant advantage with respect
to the computational time. The temperature simulations and distortion
predictions are verified by comparing with the experimental results from thermo-
couples and laser scanners, while the residual stresses are verified with the
neutron diffraction strain scanner ENGIN-X. The stress across the deposited wall
is found uniform with very little influence of the preceding layers on the
following layers. The stress redistributed after unclamping with a much lower
value at the top of the wall than at the interface due to the bending distortion
of the samp
Pomatoschistus nanus Engin & Seyhan 2017
No full text<i>Pomatoschistus nanus</i> Engin & Seyhan, 2017 (Fig. 68)—Pygmaean Goby <p> <i>Pomatoschistus nanus</i> Engin & Seyhan, 2017: 3; type locality: Turkey, Antalya, Kas, Camel Reef.</p> <p>Size. Maximum size 2.0 cm total length (Engin & Seyhan 2017).</p> <p> Morphology. D VI + I,8; A I,9–11; P 15–16 (Engin & Seyhan 2017). <b>Very small goby</b> with subcylindrical body, laterally compressed towards caudal fin, head slightly depressed and moderately small. Snout pointed. <b>Eyes large.</b> Caudal peduncle slender, lower than body depth. Dorsal fins of similar height, the first dorsal fin with more or less rounded margin and no elongated spines. Caudal fin slightly emarginate. Scales present, but not usually visible on photographs.</p> <p> Live coloration. Body mostly translucent (Fig. 68); <b>most visible chromatophores are deep inside the body, arranged along the vertebral column</b> in a white line interspersed with dark markings and then, three longer dark lines and finally an elongate spot on caudal-fin base. Superimposed on this deep pattern are <b>4 very thin dorsal white saddles and a fifth broader saddle on caudal peduncle</b>; a midlateral dark spot, that may slightly extend ventrally, below each saddle. <b>Body whitish ventrally, with vertical, iridescent, pale gray streaks. Cheeks pale</b>. Usually no horizontal Y-shaped dark marking on opercle. <b>On nape, 3 whitish to white markings just behind eyes with 2 dark longitudinal streaks in between, and underlined with dark on sides</b> (Engin & Seyhan 2017; present work).</p> <p> Similar species. <i>Pomatoschistus bathi</i>, <i>Pseudaphya ferreri</i>.</p> <p>Habitat. Infralittoral and circalittoral species, on coarse sand close to rocky reefs at depths of 29–41 m (Engin & Seyhan 2017).</p> <p>Geographic distribution. Eastern Mediterranean. Known only from the northern coast of the Levantine Sea (Engin & Seyhan 2017).</p>Published as part of <i>Kovačić, Marcelo, Renoult, Julien P., Pillon, Roberto, Svensen, Rudolf, Bogorodsky, Sergey V., Engin, Semih & Louisy, Patrick, 2022, Identification of Mediterranean marine gobies (Actinopterygii: Gobiidae) of the continental shelf from photographs of in situ individuals, pp. 1-103 in Zootaxa 5144 (1)</i> on page 80, DOI: 10.11646/zootaxa.5144.1.1, <a href="http://zenodo.org/record/6601561">http://zenodo.org/record/6601561</a>
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A comparison between Engin and Engin-X, a new diffractometer optimised for stress measurement
No full textEngineering diffractometers are used extensively by both engineers and materials scientists for the measurement of strain within polycrystalline materials, both metallic and ceramic. In the past neutron diffractometers have generally been built as ‘all-purpose’ instruments, with designs that are compromises, balancing competing requirements to measure the intensities, positions and widths of diffraction peaks simultaneously. In contrast the newly constructed diffractometer ENGIN-X was designed with the single aim of making engineering strain measurements; essentially the accurate measurement of polycrystalline lattice parameters, at a precisely determined position. Under this design philosophy, considerable performance improvements have been obtained compared to the existing instrument. This paper details the design philosophy of this instrument, including tuneable incident resolution, together with the approaches used to realise the performance required. The improved instrument performance is demonstrated here, with results obtained during the commissioning of ENGIN-X. These results include strain mapping experiments, and demonstrate the influence of resolution on required count times, and provide a direct comparison with measurements from the existing ENGIN instrument at ISIS
Hazeus ingressus Engin, Larson & Erhan 2018
No full text<i>Hazeus ingressus</i> Engin, Larson & Erhan, 2018 (Fig. 35)—Invaded Sand Goby <p> <i>Hazeus ingressus</i> Engin, Larson & Irmak, 2018: 318; eastern mediterranean, Turkey, Fethiye.</p> <p>Size. Largest specimen examined 3.7 cm total length.</p> <p> Morphology. D VI + I,8; A I,8–9; P 17–18. Body moderately elongate, the depth 5.0– 6.3 in standard length. Stout head with slightly rounded snout and large eyes extending slightly above dorsal profile. Caudal peduncle deep, but lower than body depth. <b>First spine of first and second dorsal fins stout and sharp-tipped; third spine of the first dorsal fin slightly longest but not elongate</b>. Caudal fin rounded, shorter than head length. Body, nape, cheek and opercle scaled, but scales not visible or poorly visible on live specimen photographs (Engin <i>et al</i>. 2018).</p> <p> Live coloration. <b>Pale gray with numerous small irregular brown spots on body and dorsally on head, and a row of 5 irregular blackish blotches along midside</b> (Fig. 35), first below first dorsal fin, fifth on caudal-fin base. Head with brown marking below orbit. Second dorsal fin with brown streaks along rays. <b>No rows of elongate spots on cheek and no longitudinal eye stripe</b> (Fig. 33b).</p> <p> Similar species. <i>Gobius incognitus</i>, <i>G</i>. <i>bucchichi</i>.</p> <p> Habitat. Inhabits sand bottom in sheltered bays and lagoons at depth of 5–37 m (Engin <i>et al.</i> 2018).</p> <p>Geographic distribution. Only known from the type specimens collected at Fethiye on the Levantine coast of Turkey, eastern Mediterranean Sea. It was later observed in Abu Dabab lagoon, Marsa Alam, Egypt on silty sand bottom (based on an unpublished photograph provided by B. Hazes).</p>Published as part of <i>Kovačić, Marcelo, Renoult, Julien P., Pillon, Roberto, Svensen, Rudolf, Bogorodsky, Sergey V., Engin, Semih & Louisy, Patrick, 2022, Identification of Mediterranean marine gobies (Actinopterygii: Gobiidae) of the continental shelf from photographs of in situ individuals, pp. 1-103 in Zootaxa 5144 (1)</i> on page 66, DOI: 10.11646/zootaxa.5144.1.1, <a href="http://zenodo.org/record/6601561">http://zenodo.org/record/6601561</a>
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
ENGIN-X- instrument for materials science and engineering research
No full textEngin-X is a leading neutron diffractometer for materials science and engineering, with high resolution and versatile capabilities at the ISIS spallation source, UK. Over the past 10 years Engin-X has continually redefined the frontier of stress characterisation capability through investment in state-of-the-art equipment, attracting academic and industrial users from 24 countries. Measurements are typically carried out in collaborative experiments between universities, industry and ISIS to address a wide range of engineering problems: manufacturing challenges surrounding magnesium alloys for the automotive industry, creep deformation of nickel-base superalloys for aero engines, structural integrity of welds for nuclear power plants, residual stresses in a range of samples from complex aerospace components to ancient steel making manufacturing techniques
Comparison of joining efficiency and residual stresses in laser and laser hybrid welding
No full textLaser welding is a high energy density process, which can produce welds with
less energy input and thereby lower residual stress generation compared to arc
welding processes. However, the narrow beam dimension makes it extremely
sensitive in terms of fit up tolerance. This causes a problem in achieving high
quality welds. Laser with arc hybrid process overcomes such issues. In this
paper, longitudinal residual strains were compared for autogenous laser welding
and laser/TIG hybrid processes. Joining efficiency, which is defined by the
penetration depth achieved per unit of energy input, was correlated with the
residual strain generation. It has been shown that to achieve a specific
penetration depth, there is an optimum welding condition for each of the welding
processes, which will give minimum tensile residual stress generation. The
results imply that for the same penetration depth, hybrid process resulted in
similar to 50% higher tensile longitudinal domain compared to autogenous laser
A comparison of strain measurements on an inertia friction weld using the ENGIN-X and SALSA neutron strain mapping instruments
No full textIn this study we present a direct comparison between residual strain measurements carried out on the same inertia friction weld using ENGIN-X at ISIS, UK and the new strain scanner SALSA at ILL, France. ENGIN-X is a time of flight (TOF) instrument, which receives neutrons from a neutron spallation source, while the SALSA Strain-Imager, a high resolution diffractometer, is based at a research reactor source with a continuous neutron flux and is operated with a constant wavelength. The purpose of this study was to demonstrate a confidence in crosscomparing future strain measurements to be performed at ENGIN-X and SALSA. Measurements were carried out on medium size inertia friction welded nickel superalloy test-piece, which show no significant crystallographic texture across the weld line. The results demonstrate that, even though residual stresses determined on SALSA only rely on a single peak analysis (in this case the (111) reflection), the results show excellent agreement with the measurements carried out on ENGIN-X, where strain is determined from multi-peak Rietveld analysis
Pragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
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