132,002 research outputs found
Large water-hammer pressure for column separation in pipelines
No full textWater-hammer pressures in a pipeline due to the collapse of a vapor cavity adjacent to a valve are investigated. A water-hammer event is initiated by the closure of a valve in a simple reservoir-pipeline-valve system. The sequence of events following an instantaneous valve closure leading to the formation and collapse of a vapor cavity and the resultant occurrence of a short-duration pressure pulse are described. Short-duration pressure pulses result from the superposition of the valve-closure water-hammer wave and the wave generated by the collapse of the vapor cavity. The resulting maximum pressure may exceed the Joukowsky pressure generated from the initial valve closure. A series of numerical model analyses exhibiting short-duration pressure pulses are presented. In addition, experimental results supporting the findings of the numerical studies are also presented. Experimental plots of hydraulic grade line versus time exhibit short-duration pressure pulses of different shape and characteristics.Angus R. Simpson and E. Benjamin Wyli
Do Chimpanzees Use Weight to Select Hammer Tools?
No full textThis study was financially supported by a Japan Society for the Promotion of Science Predoc Grant (http://www.jsps.go.jp/english/e-summer/index.html) to Cornelia Schrauf. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.The extent to which tool-using animals take into account relevant task parameters is poorly understood. Nut cracking is one of the most complex forms of tool use, the choice of an adequate hammer being a critical aspect in success. Several properties make a hammer suitable for nut cracking, with weight being a key factor in determining the impact of a strike; in general, the greater the weight the fewer strikes required. This study experimentally investigated whether chimpanzees are able to encode the relevance of weight as a property of hammers to crack open nuts. By presenting chimpanzees with three hammers that differed solely in weight, we assessed their ability to relate the weight of the different tools with their effectiveness and thus select the most effective one(s). Our results show that chimpanzees use weight alone in selecting tools to crack open nuts and that experience clearly affects the subjects' attentiveness to the tool properties that are relevant for the task at hand. Chimpanzees can encode the requirements that a nut-cracking tool should meet (in terms of weight) to be effective.Peer reviewe
Roynortonella gildersleeveae Hammer 1952, n. comb.
No full textRoynortonella gildersleeveae (Hammer, 1952) n. comb. (Figs. 32–37) Gymnodamaeus gildersleeveae Hammer, 1952 Nortonella gildersleeveae (Hammer, 1952) (Paschoal 1982 c) Paschoalia gildersleeveae (Hammer, 1952) (Özdikmen 2008) Material examined: CANADA, NORTHWEST TERRITORIES: syntype Yellowknife (62 º 40 ’N, 114 ° 20 ’W) near Great Slave lake, ex small depression among rocks under spruce with moss, liverworts, lichens and old needles and leaves, M. Hammer. ALBERTA: 5 adults, Lamont County (53 º 39 ’N, 112 ° 46 ’W) ex dry litter on SW slope, 20.vi 8 i. 2008, D.E. Walter; 1 adult, Edmonton River Valley, ex dry litter, 12.v. 2009, S. Latonas; 1 adult, ABMI site 330 (57.66861725 N, - 110.962219 W), 2007; 1 adult, ABMI site 618 (56.38592148 N, - 117.012878 W), 2007. Comments. In her description, Hammer (1952) said “Tectopedia I and II have stout points” (p. 29), but this appears to be a misinterpretation of the pedotecta as being linear. In fact, they are ear-shaped with rounded margins (e.g. Figs. 34, 36) as in all Gymnodamaeidae that I have seen except Pleodamaeus. She also missed the interlamellar setae that are covered in dense cerotegument and closely inserted on apophyses on the medial margins of the bothridia.Published as part of Walter, David Evans, 2009, Genera of Gymnodamaeidae (Acari: Oribatida: Plateremaeoidea) of Canada, with notes on some nomenclatorial problems, pp. 23-44 in Zootaxa 2206 on page 39, DOI: 10.5281/zenodo.18974
"Lieber St. Petrus" - "Liebe Tino". Der Briefwechsel von Else Lasker-Schüler und Peter Hille
No full textRottschäfer N. "Lieber St. Petrus" - "Liebe Tino". Der Briefwechsel von Else Lasker-Schüler und Peter Hille. In: Jahn H, ed. Jeder Vers ein Leopardenbiss . Else-Lasker-Schüler-Almanach. Vol 9. Wuppertal: Hammer; 2011: 62-85
How to Quantitatively Compare Data Dissimilarities for Unsupervised Machine Learning?
No full textMokbel B, Gross S, Lux M, Pinkwart N, Hammer B. How to Quantitatively Compare Data Dissimilarities for Unsupervised Machine Learning? In: Mana N, Schwenker F, Trentin E, eds. Artificial Neural Networks in Pattern Recognition. 5th INNS IAPR TC 3 GIRPR Workshop, ANNPR 2012. Proceedings. Lecture Notes in Artificial Intelligence. Vol 7477. Springer Berlin Heidelberg; 2012: 1-13
Multioppia HAMMER 1961
No full textMultioppia HAMMER, 1961 The main characteristics of the genus Multioppia are the following: Sensilli pectinate or fusiform, lamellar line present or absent, interlamellar region with three pairs of areola in two longitudinal rows, notogaster with twelve pairs of setae, genital setae numbering five pairs, aggenital setae one pair, anal setae two pairs, adanal setae three pairs, lyrifissures iad in paraanal position. Type species: Multioppia radiata HAMMER, 1961Published as part of Toluk, A., Ayyildiz, N. & Subías, L., 2009, Three New Species Of The Family Oppiidae (Acari, Oribatida) From Turkey, pp. 11-21 in Acta Zoologica Academiae Scientiarum Hungaricae 55 (1) on page 12, DOI: 10.5281/zenodo.573190
A general systems approach to applying seasonal climate forecasts
No full textAgricultural and natural ecosystems and their associated business and government systems are diverse and varied, ranging from farming systems to water resource systems to species population systems to marketing and government policy systems, among others. These systems are dynamic and responsive to fluctuations in climate. Production, profit, conservation, and policy issues provide the major focus for intervention in these systems. Risk, or the chance of incurring a financial or environmental loss, is a key factor pervading decision-making. Skill in seasonal climate forecasting offers considerable opportunities to managers via its potential to realise system improvements tie. increased profits and/or reduced risks). Realising these opportunities, however, is not straightforward as the forecasting skill is imperfect and approaches to applying the existing skill to management issues have not been developed and tested extensively
Applying seasonal climate forecasts in agricultural and natural ecosystems - A synthesis
No full textThe chapters contributed to this book express a wealth of knowledge and experience on generating and applying seasonal climate forecasts in agricultural and natural ecosystems, In the introductory section the impact of climate variability and the potential for using seasonal forecasts in managing climate risks were outlined. It was made clear that climate forecasts must be phrased as probabilistic statements, The concept of a general integrated systems approach to applying forecasts across a range of scale from farm to region and nation was introduced. This concept focussed on deriving the targeted information needs of decision-makers in a manner that captured the value of the climate forecast. It was suggested that, as the climate forecast only acquired value when decisions were modified in response to it, then a focus on decision-making in the target systems was an appropriate basis to structure the contributions to this book. While systems across the range of scale involved diverse decision-makers and issues ranging from resource management to policy, the general approach was relevant in all cases. The aim of this paper is to synthesise key issues fi-om those contributions and to discuss them in a way that might guide future activities
Nonlinear Dimension Reduction and Visualization of Labeled Data
No full textBunte K, Hammer B, Biehl M. Nonlinear dimension reduction and visualization of labeled data. In: Jiang X, Petkov N, eds. International Conference on Computer Analysis of Images and Patterns. Lecture Notes in Computer Science, 5702. Vol 5702. Berlin: Springer; 2009: 1162-1170
Georgene W. Davis. The Inquisition at Albi, 1299-1300. Text of Register and Analysis (Columbia University, Studies in History, Economics and Public Law, n° 538)
No full textHammer J. Georgene W. Davis. The Inquisition at Albi, 1299-1300. Text of Register and Analysis (Columbia University, Studies in History, Economics and Public Law, n° 538). In: Scriptorium, Tome 3 n°2, 1949. pp. 333-334
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