2,117 research outputs found
Solution of the problem of composite charge using R.D.38
No full textIn this paper the author has solved the problem of internal ballistics of composite charge using 'R.D.38' method which is based upon the usual isothermal approximation. A linear law of burning has been assumed
Author index
No full textThe articles have been scanned in colour with a HP Scanjet 5590; 300dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.This is a continuation of the "Author and Subject Index to the Onderstepoort Journal
of Veterinary Science and Animal Industry (1933- l950)" and the "Onderstepoort Journal
of Veterinary Research (1951 - 1968)" which appeared in June 1969 and covers the period
1969 to 1973, i.e. Volumes 36 to 40.
As from 1974 (Volume 41) it is intended to furnish an Author and Subject Index
in Number 4 of each volume covering all four numbers for that particular year
Noise due to unsteady flow past trailing edges
No full textThis paper presents two-dimensional direct numerical simulations (DNS) of noise generated at trailing edges (TE) with zero thickness. The simulations are conducted specifying either no-slip or slip walls in order to investigate viscous effects. In both cases, small amplitude disturbances are introduced close to the inflow boundary that serve as pressure disturbances at the TE. DNS data reveals that the unsteady Kutta condition is not satisfied, irrespective of the wall boundary condition. However, it appears that the validity of the unsteady Kutta condition is not essential for making an accurate prediction of the far field noise. The far field pressure is predicted as a function of the surface pressure difference using a 2-D modification of Amiet's classical theory, and compared with the far field pressure computed directly. Directivity plots provide evidence that the presence of boundary layers and noise generated by an unsteady wake in the no-slip cases lead to smearing of individual lobes, and that the downstream pointing lobes in no-slip wall cases are probably due to nonlinear noise generation in the wake. The simulations are conducted using a high-order accurate numerical method which is free of upwinding, artificial dissipation or any form of explicit filtering, and employs a novel boundary treatment
Characteristic distribution and scale interaction of turbulence in a boundary layer
No full textThis work revisits the concept of turbulent boundary layers from a novel perspective on scale transfer. Turbulence production and dissipation together with the energy budgets are analyzed in the velocity gradient invariant phase space. In combination with filtering, the mechanism of scale coupling is investigated and illustrated for different characteristic flow topologies. The understanding of the scale coupling is important to model turbulence. Turbulence models describe the complex interaction of the scales of motion in a simplified form. The essential task of turbulence modeling is to capture the coupling of the modeled and unmodeled scales as well as the evolution of the modeled scales within the unmodeled flow. This work characterizes the scale coupling by focusing on the interfaces between modeled and unmodeled flow such as production and dissipation. The mechanisms that govern the evolution of the modeled quantities are investigated for their core properties and universal features. Direct numerical simulation (DNS) is carried out to obtain data of a compressible zero pressure-gradient flat plate turbulent boundary layer flow. This flow topology allows to unveil the effect of a wall on the coupling of scales and evolution of turbulence
Learning from One's Mistakes
No full textCreated by R.D. Lee for the Royal Statistics Society, this article describes an exercise, which highlights the effect of sampling without replacement in small populations, and leads to consideration of the relative importance of sample and population size when examining standard error. The author provides a number of exercises, an explanation of statistical errors and the importance of sample size. This is a brief, yet fine resource for those in the field of statistics
Mad to be Normal: Thoughts on Psychiatrist R.D Laing and Connections to Liberation Psychology
No full textThis article uses the film Mad to be Normal, about R.D. Laing, as an opening into the liberation psychology approaches of Martin-Baro. Examples from the author\u27s own clinical practice as well as personal experiences from life in a Catholic Worker community are included
R.D. Laing's language of experience
No full textThe radical psychiatrist R.D. Laing (1927-1989) was an accomplished author with an extensive philosophical knowledge that informed his ideas on reading, writing, and interpretation. Laing argues that psychiatry should be modeled on skilful textual exegesis rather than scientific explanation. The exegesis of a psychotic’s words and actions is difficult, he infers, because the impoverishment of our experience cuts us off from the sense that lies within seeming madness. Like philosophers such as Edmund Husserl, Laing therefore criticizes the way in which the natural sciences have invalidated subjective experience. He consequently employs a rhetoric designed to disclose with renewed vigor its complexity, variety and reality. Laing fails, however, to find an alternative to scientific reason: "experience", in his weakest work, is an irrational realm of mystical and self-validating certainty that closely parallels Heidegger’s later accounts of "Being"
Ceracis tzotzilicus Souza-Gonçalves & Lopes-Andrade 2020, sp. nov.
No full textCeracis tzotzilicus sp. nov. Figs 1–22 urn:lsid:zoobank.org:pub: BDA42D7F-AEC0-4F5F-895B-1D3F46FBC728 Type locality. San Cristóbal de las Casas, coordinates 16º44’N 92º38’W (Chiapas, Mexico). Type material. Holotype: ♂ (CNC) “ MEX., HIS., 3 mi. N. S. Cristobal de las Casas 12.VI.1969 E.E. Lindquist \ Bracket fungi \ Ceracis tzotzilicus Souza-Gonçalves & Lopes-Andrade HOLOTYPUS [red paper]”. Paratypes: 121 ♂♂ and 78 ♀♀ as follows: 105 ♂♂ (35 CELC, four dissected; 3 CMN; 67 CNC) and 69 ♀♀ (22 CELC, two dissected; 1 CMN; 46 CNC) same data as the holotype; 2 ♂♂ (1 CMN; 1 CNC) “ MEX., HIS., 3 mi. N. S. Cristobal de las Casas 12.VI.1969 E.E. Lindquist \ Bracket fungi \ Ceracis sp. Det. J.F. Lawrence ”; 15 ♂♂ (8 CELC, one dissected; 7 FMNH) and 9 ♀♀ (5 CELC; 4 FMNH) “ Finca Monserat, W. slope Volcan Acatenango, Município Yepocapa, Chimaltenango, V:17:1948 GUAT. R.D. Mitchell leg. 214.7100 ft., ex dry polypore fungus \ CHICAGO NAT. HIST. MuSEUM [sic], Guatemala Zool. Exped. (1948)”. All paratypes additionally labeled “ Ceracis tzotzilicus Souza-Gonçalves & Lopes-Andrade PARATYPUS [yellow paper]”. Diagnosis. Ceracis tzotzilicus sp. nov. can be distinguished from other species in the genus by the following characteristics: Antennae 9-segmented (Fig. 5). Males with anterocephalic edge produced and elevated forming a wide lamina, which is broadly emarginate apically (Figs 1, 3), and pronotum deeply emarginate forming two triangular plates (Figs 1, 3, 4). C eracis tzotzilicus sp. nov. resembles Ceracis bicornis (Mellié) in the fine and sparse pronotal punctation, but in the latter species the male anterocephalic lamina is straight at apex and female ovipositor has conspicuous gonostyli. Description, male holotype (Figs 1–4). Adult, fully pigmented and in good condition, but lacking the left antenna. Measurements in mm: TL 1.67, PL 0.64, PW 0.67, EL 1.04, EW 0.72, GD 0.67. Ratios: PL/PW 0.95, EL/ EW 1.44, EL/PL 1.63, GD/EW 0.93, TL/EW 2.33. Body elongate, convex; dorsum and venter reddish dark brown; antennae yellowish brown, club dark brown; palpi and tarsi yellowish brown; dorsal vestiture single, consisting in minute suberect setae, barely visible at high magnifications (>50x); ventral vestiture of fine decumbent setae easily discernible at high magnifications (>50x). Head with the anteriormost portion visible from above; dorsum concave, with a conspicuous, short protuberance on vertexal disc; punctures fine, shallow, separated from each other by two punctures-widths or less; surface glabrous; interspaces, finely microreticulate; anterocephalic edge produced and elevated, forming a wide lamina with broadly emarginate apex. Antennae (Fig. 5, left antenna from paratype) 9- segmented, lengths as follows (in mm, right antenna measured): 0.08, 0.04, 0.03, 0.02, 0.02, 0.01, 0.05, 0.06, 0.07 (FL 0.08 mm, CL 0.17 mm, CL/FL 2.04). Eyes coarsely facetted; each bearing about 90 ommatidia; GW 0.16 mm. Maxillae (Fig. 8, right maxilla in paratype) with distinctly articulated galea; lacinia more or less fused to stipes; apical maxillary palpomere pyriform, 1.5X as long as wide, widest near base and narrowly rounded at apex. Mandibles (Fig. 6, from paratype) as long as wide. Labium (Fig. 7, from paratype) with rounded contour of apical portion of prementum in lateral view; labial palpi each with three palpomeres. Gula 0.32x as wide as head. Pronotum (Fig. 4) finely, shallowly punctate; punctures of one size, with the exception of median impunctate line beginning around eight puncture-widths of base until disc; punctures scattered, separated from each other by 2–3 puncture-widths; interspaces microreticulate and shiny; vestiture single, consisting of minute, pale yellowish setae (<0.01 mm); anterior pronotal edge deeply emarginate forming two short triangular plates, slightly divergent and with acute apex; lateral edges not crenulate, not explanate and not visible when seen from above. Scutellar shield triangular, bearing few punctures and few minute setae; BW 0.10 mm, SL 0.07 mm. Elytra with non-seriate, dual punctation; megapunctures finer and closer than those on pronotum, shallow, about twice as large as micropunctures, separated from each other by 1–2 megapuncture-widths; interspaces, smooth and shiny; vestiture single, consisting of minute pale yellowish setae (~ 0.01 mm) arising from megapunctures. Metathoracic wings developed, apparently functional. Hypomera with fine, shallow punctation; each puncture bearing one fine decumbent seta; interspaces microreticulate. Prosternum in front of coxae concave; interspaces, microreticulate. Prosternal process laminate, as long as prosternum at midline; acute at the apex. Protibiae (Fig. 9, left protibia from paratype) with maximum width of about one-fourth of its length, expanded at apex. Meso- and metatibiae (Figs 10–11, left meso- and metatibia from paratype) each with spines in apical edge. Metaventrite with fine, shallow punctures; interspaces, microreticulate; discrimen indiscernible. Abdominal ventrites with fine, shallow punctures, separated from each other by one puncture-width or less, each bearing one fine decumbent pale yellowish seta; interspaces, microreticulate; length of ventrites (in mm, from base to apex at the longitudinal midline) as follows: 0.25, 0.08, 0.06, 0.07, 0.10; first abdominal ventrite with large circular, setose sex patch posteriorly, not margined, transverse diameter of 0.08 mm. Male terminalia (from paratype) (Figs 12–15): Sternite VIII (Fig. 12) with posterior margin slightly emarginate medially; corners broadly rounded, bearing long and short setae; lateral margins diverging; anterior margin biconcave, sub-rounded, heavily sclerotized medially forming short strut (Fig. 12, big black arrow). Tegmen (Fig. 14) 2X as long as wide, widest near apex, apical portion deeply and broadly emarginate; lateral edges angulate near apex; outer apical edge broadly rounded. Basal piece (Fig. 13) subtriangular, 1.4X as long as wide. Penis (Fig. 15) elongate, 0.8X as long as tegmen, 4.9X as long as wide; lateral edges sclerotized forming two struts converging near apex; lateral edges slightly angulate near apex (Fig. 15, small black arrows); apex rounded. Females (Figs 16–18). Anterocephalic edge anteriorly truncate, barely convex; vertex convex. Anterior pronotal edge rounded. Otherwise like males, but devoid of head and pronotal ornamentations, and abdominal sex patch. Female terminalia (Figs 17–18) with spiculum ventrale (Fig. 17) 1.7X as long as gonocoxites; ovipositor (Fig. 18, distorted after compression between slide and cover slip) presenting reduced paraprocts, shorter than gonocoxites and barely discernible; each baculus of paraprocts bowed and completely fused to respective proctigeral baculus (Fig. 18); gonocoxites without ventral lobes and gonostyli. Variation. Males, measurements in mm (n= 11, including the holotype): TL 1.58–1.78 (1.67 ± 0.07), PL 0.55– 0.68 (0.62 ± 0.04), PW 0.63–0.70 (0.67 ± 0.02), EL 0.95–1.18 (1.05 ± 0.07), EW 0.65–0.75 (0.71 ± 0.03), GD 0.63–0.70 (0.65 ± 0.04), PL/PW 0.85–1.00 (0.93 ± 0.05), EL/EW 1.36–1.59 (1.48 ± 0.07), EL/PL 1.41–1.96 (1.70 ± 0.18), GD/EW 0.88–0.93 (0.91 ± 0.02), TL/EW 2.23–2.43 (2.36 ± 0.06). In some males, the pronotal plates are short (Fig. 19) or the plate of head is short and pronotal edge is rounded (Figs 20–21). Females, measurements in mm (n= 10): TL 1.45–1.73 (1.63 ± 0.08), PL 0.53–0.63 (0.58 ± 0.06), PW 0.55–0.70 (0.64 ± 0.05), EL 1.00–1.10 (1.05 ± 0.04), EW 0.63–0.78 (0.70 ± 0.05), GD 0.58–0.70 (0.65 ± 0.04), PL/PW 0.82–1.00 (0.91 ± 0.05), EL/EW 1.37–1.68 (1.50 ± 0.10), EL/PL 1.64–2.22 (1.82 ± 0.17), GD/EW 0.83–0.97 (0.93 ± 0.05), TL/EW 2.13–2.52 (2.32 ± 0.11). In both males and females, coloration can range from reddish brown to reddish dark brown. In specimens from Guatemala the pronotal punctation is slightly sparser than in the Mexican specimens. Host fungi. Unknown. Etymology. The species epithet is a combination of the terms “tzotzil” and the Greek noun “ikos” (=belonging to), both in the genitive singular. The name is a reference to the Tzotzil, an indigenous Maya people from the central Chiapas highlands in southern Mexico, which is also the native name of the type locality. Distribution. Ceracis tzotzilicus was collected in two localities over 2000 m above sea level: Central Highlands region of Chiapas (Mexico) dominated by Coniferous Forest vegetation, and in the stratovolcano Acatenango close to Antigua (Guatemala) (Fig. 22). Comments. Currently, four species-groups are recognized within Ceracis (number of species between parentheses): the cucullatus (10), furcatus (4), furcifer (4) and singularis species-groups (3). This arrangement leaves 32 species (including Cer. tzotzilicus) without species-group assignment within the genus. The cucullatus- group was revised by Antunes-Carvalho & Lopes-Andrade (2011, 2013), with four new species from Australia added by Lawrence (2016). Within the cucullatus -group, Cer. bicornis (Mellié) is the unique species that was not redescribed yet and may be a species complex. The furcatus- group was established by Lopes-Andrade (2002) and may include possible synonyms (Lawrence 1967); it is in urge of a taxonomic revision. The furcifer- group was recently revised by Pecci-Maddalena & Lopes-Andrade (2017). The singularis group was established by Lopes-Andrade et al. (2002) and its species seem to be well defined. Although Cer. tzotzilicus resembles Cer. bicornis (see Diagnosis), we prefer not to assign it to either the cucullatus or any other species-group within Ceracis. We are currently conducting a phylogenetic analysis and major taxonomic propositions will be provided in forthcoming works.Published as part of Souza-Gonçalves, Igor & Lopes-Andrade, Cristiano, 2020, Ceracis tzotzilicus sp. nov. (Coleoptera: Tenebrionoidea: Ciidae) from Guatemala and Mexico, pp. 379-386 in Zootaxa 4780 (2) on pages 380-385, DOI: 10.11646/zootaxa.4780.2.10, http://zenodo.org/record/384244
Naval engineering and ship control special edition editorial
No full textEditorial Special Issue: Naval Engineering and Ship Control IIGreen Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Ship Design, Production and Operation
Using and evaluating CASE tools : from software engineering to phenomenology
No full textCASE (Computer-Aided Systems Engineering) is a recent addition to the long line of
"silver bullets" that promise to transform information systems development, delivering
new levels of quality and productivity. CASE is particularly intriguing because
information systems (IS) practitioners spend their working lives applying information
technology (IT) to other people's work, and now they are applying it to themselves.
CASE research to date has been dominated by accounts of tool development,
normative writings (for example practitioner success stories) and surveys recording
IT specialists' perceptions. There have been very few in-depth studies of tool use,
and very few attempts to quantify benefits, therefore the essence of the CASE process
remains largely unexplored, and the views of stakeholders other than the IT specialists
have yet to be heard.
The research presented here addresses these concerns by adopting a hybrid research
approach combining action research, grounded theory and phenoinenology and using
both qualitative and quantitative data in order to tell the story of a system developer's
experience in using CASE tools in three information systems projects for a major UK
car manufacturer over a four year period. The author was the lead developer on all
three projects. Action research is a learning process, the researcher is an explorer.
At the start of this project it was assumed that the tools would be the focus of the
work. As the research progressed it became evident that the tools were but part of
a richer organisational context in which culture, politics, history, external initiatives
and cognitive limitations played important roles. The author continued to record
experiences and impressions of tool use in the project diary together with quality and
productivity metrics. But the diary also became home to a story of organisational
developments that had not originally been foreseen.
The principal contribution made by the work is to identity the narrow positivistic
nature of CASE knowledge, and to show via the research stories the overwhelming
importance of organisational context to systems development success and how the
exploration of context is poorly supported by the tools. Sixteen further contributions
are listed in the Conclusions to the thesis, including a major extension to Wynekoop
and Conger's CASE research taxonomy, an identification of the potentially
misleading nature of quantitative IS assessment and further evidence of the limitations
of the "scientific" approach to systems development.
The thesis is completed by two proposals for further work. The first seeks to
advance IS theory by developing further a number of emerging process models of IS
development. The second seeks to advance IS practice by asking the question "How
can CASE tools be used to stimulate awareness and debate about the effects of
organisational context?", and outlines a programme of research in this area
- …
