bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sulphate resistance and long-term strength properties of regulated-set cements
Authors: Osborne G. J. , Smith M. A. 
Published: October 2009

Synopsis The results of compressive strength tests and durability tests on mortars and concretes made with two commercially produced regulated-set cements manufactured outside the UK for ages up to 6 months have been reported previously. The present paper gives the results of longer-term strength tests and sulphate-resistance tests up to 2 years. At ages greater than 24 h the regulated-set cements show little advantage over ultra-rapid-hardening Portland cement in terms of compressive strength, whilst at ages beyond 28 days performance is similar to that of ordinary Portland cement. Sulphate resistance is poor, but is much improved by the addition of pulverized-fuel ash. Some information is given on the performance of ultra-rapid-hardening Portland cement for comparison.
Activation energy of creep of concrete under short-term static and cyclic stresses
Authors: Hirst G. A. , Neville A. M. 
Published: October 2009

Synopsis A theoretically derived relation which has previously been shown by other authors to agree well with static creep is extended and transformed so that cyclic creep can be related to static creep as a function of the range of stress and time. Experimental results for periods under load up to 160 h show excellent agreement with the theory. The time dependence of the relation between cyclic creep and static creep is unclear from the short-term data used, but long-term data should clarify the function. With the relation fully defined, it would be a useful extension to the methods of predicting creep given in a number of codes of practice.
Fluid-pressure testing of concrete cylinders
Authors: Clayton N. 
Published: October 2009

Synopsis The paper describes experiments on the behaviour of standard concrete cylinders subjected to fluid pressure applied to their curved surface without the use of an intervening membrane. The results of two sets of tests are given: one set carried out by using water pressure, the other by using nitrogen gas pressure. The fracture pressures of the cylinders are given at each of four different rates of applied pressure, and the significance of the results is stated.
Torsion–shear–flexure interaction in reinforced concrete members
Authors: Ewida A. A. , McMullen A. E. 
Published: October 2009

Synopsis An analysis for predicting stresses, strains and rotations at all levels of load and for predicting the strength of members under combined torsion–shear–flexure loads is presented. Equilibrium and compatibility are considered and the analysis predicts the phenomenon of ‘shear relief’, whereby the torsional strength of an over-reinforced beam is enhanced by a small shear load. A torsion–shear–flexure interaction surface is proposed which is actually a combination of two surfaces. An equation defining the space curve formed by the intersection of these two surfaces is derived. Use of this equation indicates the portion of the interaction surface that is appropriate for a particular combination of loads. The proposed interaction surface is compared with test results available in the literature and good correlation is noted.
Influence of loading history upon the tensile properties of concrete
Authors: Cook D. J. , Chindaprasirt P. 
Published: October 2009

Synopsis In this paper, the influence of sustained and cyclic load regimes upon the tensile properties of concrete and paste is reported. The results indicate that prior loading of any form reduces the strength of concrete on reloading. For paste, however, the effect is not so marked and a slight increase in strength is observed after cyclic preloading. Strain to peak stress on reloading follows the same trends as strength, whilst the elastic modulus of both paste and concrete is reduced on reloading, irrespective of the mode of previous loading. It is considered that, for concrete, the damage resulting from the initial loading produces limited microcracking at the aggregate-matrix interface, which propagates due to a time- (and load-) dependent mechanism previously proposed. For cement paste, the initial damage and hence microcracking is much less and hence the consequent effect of the prior loading regimes upon the properties of the paste is also less than for concrete.
Modelling the stress-strain relationship of structural concrete
Authors: Noor F. A. , Wijayasri S. 
Published: October 2009

Synopsis Recent research has led to an improvement in the properties of model reinforcement, but similitude of deformations, over the complete range of loading, andshear strength has not been achieved. It is well known that a number of size effects are due mainly to the properties of microconcrete because, in comparison with structural concrete, this material is stronger in tension and more ductile in compression. As a result of a detailed investigation into the compressive to tensile strength ratio and the stress-strain relationship of various model concrete mixes, a new type of microconcrete has been produced. The new mix is gap-graded, some of the coarsesand particles being replaced by glass beads, It has been tried in a number of model beams with an over-all depth of 30 mm and has given useful results.
Bimoment design of some rectangular slabs
Authors: Gurley Colin R. 
Published: October 2009

Synopsis This paper continues the development of practicable design-office methods for the plastic (‘yield-line’) design of slabs considered as torsion-free (Hillerborg) grillages. In particular it recognizes a more general class of problem in which the yield lines will be curved on plan andsuggests some expedient approximate methods for such problems. It also treats some cases of slabs which are irregular in that they incorporate cut-outs and/or line loads as well as area-distributed loads.
A graphical solution for predicting the increase in strength of concrete slabs due to membrane action
Authors: Eyre J. R. , Kemp K. O. 
Published: October 2009

Synopsis A simple graphical procedure for determining the effect of membrane action upon the load capacity of a rigid-perfectly-plastic reinforced concrete slab is presented. The load-enhancement-deflection curve is derived by asimple reflection of the yield criterion curve for the concrete section under axial force and moment. The method provides an immediate understandingof the effect of section design upon the load enhancement to be expected from membrane action.
The permeability of concrete in a marine environment
Authors: Buenfeld N. R. , Newman J. B. 
Published: October 2009

Synopsis Permeability is a fundamental property governing the durability of concrete in the marine environment and it has only recently been appreciated that some concretes exhibit a very significant reduction in permeability on immersion in sea-water. To investigate this phenomenon further, a resistivity technique has been developed and used to monitor the changes in permeability of five mortars and one concrete on exposure to sea-water. All mixes studied showed a fall in permeability (increase in resistance) on immersion in sea- water. Indeed 25 mm thick specimens of the two most permeable mortars showed a fall equivalent to over 20 mm of additional thickness after only 10 weeks. This increase is due to the formation of an aragonite-brucite layer on the surface of the mortar plus a more widespread progressive constriction of the cement paste pore system. This effect also has a considerable influence upon the absorption capacity of concrete after a period of drying, which is important in the tidal and splash zones.
Superplasticized flowing concrete: durability properties
Authors: Dhir Ravindra K. , Yap Andrew W. F. 
Published: October 2009

Synopsis This second paper reporting the investigation undertaken into the properties of superplasticized highworkability concrete describes the freezing-and-thawing and wetting-and-drying durability of strictly flowing concrete. It is shown that flowing concrete with a cement content equal to or greater than the minimum specified for a structural concrete under these exposures is more susceptible to deterioration than normal concrete having the same mix composition and hence the same strength. This was much more apparent in the case of freezing and thawing where, to attain a comparable response, flowing concrete would require an additional cement content of the order of 100 kglm3 or air-entrainment, the latter being found to be a better remedy.
Permeability of normal and lightweight mortars
Authors: Nyame B. K. 
Published: October 2009

Synopsis Permeabilities of normal and lightweight mortars have been determined and related to pore structure from mercury porosimeter analyses. It was found that lightweight mortar is only about twice as permeable as sand mortar of equal aggregate volume concentration. Permeability of mortar increases as porosity is reduced by the addition of aggregates of lower porosity. In principle, the decision to use dry aggregates is safer for the durability control of concrete mortars.
Shear displacement in open-sandwich reinforced concrete beams
Authors: Wong Carlos C. K. , Vardy Alan E. , Lark Robert J. 
Published: October 2009

Synopsis The deflections of open-sandwich, reinforced concrete beams under load are analysed to verifv that shear deformation of the adhesive layer between the concrete beam and its steel reinforcing plate does not cause an unacceptable loss of structural interaction. The cumulative effect of the shear deformation, i.e. the ‘shear displacement’, is loosely analogous to the slip of steel bars in a conventionally reinforced concrete beam. The partial interaction theory introduced by Newmark et al and extended by Goodman and Popov and others is further extended to include thermal expansions, cracked concrete, and unsymmetrical loading. The accuracy of the resulting analysis is assessed by comparisons with finite element predictions and with experimental results. It is found that thin layers of adhesives with a large shear modulus are preferable from an in-service structural point of view. They lead to small shear displacements and to good control of the influence of flexural cracks.
A water absorption test for concrete
Authors: Kelham S. 
Published: October 2009

Synopsis The durability of concrete near an exposed surface is largely determined by the rate at which harmful agents can penetrate into the concrete. This paper presents a simple analysis of the penetration of' water into unsaturated concrete and describes a method by which the material constant that determines the rate of penetration, the sportively, can be measured, together with the effective porosity. The sorptivity is found to depend on the permeability and porosity of the concrete and the strength of capillary forces. The experimental results conform well to the predictions of the analysis and significant variations in sorptivity have been observed for concrete containing cement replacement materials and subject to different curing regimes.
Bond between steel strand and cement grout in ground anchorages
Authors: Laldji S. , Young A. G. 
Published: October 2009

Synopsis Bond action between prestressing strand and cement grout is examined both theoretically and experimentally. Variations in strand type, embedment length, grout strength and lateral compression are investigated using a modified pull-out specimen and a simple test rig. The results support the recommended value of ultimate bond stress of 2 N/mm2proposed in the British Standard Draft for Development DD81: 1982 but show that this value may be trebled by the introduction of biaxial lateral pressure. A theoretical expression is derived, based on a frictional force mechanism, which predicts the bond strength of normal and Dyform strand. The bond characteristics of indented strand are found to be similar to those of deformed bars. A wedge action, which is attributed to “lack ofjit” of strand within the grout channel, is shown to play an important role in the establishment of a stable load/slip bond characteristic.
Perbla and Tolmin formations: revised Toarcian to Tithonian stratigraphy of the Tolmin Basin (NW Slovenia) and regional correlations
Authors: Rožič Boštjan 
Published: October 2009

AbstractThe succession of the Tolmin Basin forms the foothills of the Julian Alps in northwestern Slovenia. In the Jurassic, it was part of the southern Tethyan passive continental margin. The basin was located between the Dinaric Carbonate Platform in the south and the Julian High in the north. Six sections were studied that encompass the stratigraphic interval from the Toarcian to the lower Tithonian. The basinal background deposits are generally marl, siliceous limestone, and radiolarian chert, whereas in the southern part of the basin resedimented limestones occur. The studied succession lies between the Lower Jurassic Krikov Formation (resedimented and hemipelagic limestones) below and upper Tithonian to Neocomian Biancone Limestone above.Two formations are described in this paper: (1) The Toarcian Perbla Formation was introduced by Cousin [1973] and is revised herein. It is composed of marl and subordinate calcareous shale with rare intercalated calciturbidites. The material was redeposited only within the basin or from its marginal parts. The thickness of the formation varies significantly through the basin from 2 to 135 metres; (2) The Tolmin Formation is herein defined. It is divided into two members. The lower member (Aalenian to lower Bajocian) consists of siliceous limestone and rare chert, whereas the upper member (upper Bajocian to lower Tithonian) is composed of radiolarian chert that locally in the upper part contains abundant marl intercalations. In the southern part of the basin, two intervals of resedimented limestones occur in the Tolmin Formation. The lower interval (lower Bajocian to lower Callovian) is dominated by calcarenite (rich in peloids and ooids) and limestone breccias. The upper interval (upper Kimmeridgian to lower Tithonian) is characterized by calcarenite, composed mostly of intraclasts and bioclasts. The source area of the carbonate material was the Dinaric Carbonate Platform.The correlation of the background sediments with other basins of the western Tethys reveals that (1) the late Toarcian decrease in terrigenous input, the Bajocian change from calcareous to siliceous sedimentation and the late Tithonian onset of carbonate sedimentation are regional and (2) the silica content in the Tolmin Basin was higher than that in the western basins (e.g. the Belluno, Lombardian, Umbria-Marche and Subbetic basins) but lower than that in the Budva Basin. The Bajocian to Callovian resedimented limestones of the Tolmin Basin are much thinner than the corresponding deposits in the Belluno and Budva basins (25 metres vs. up to 600 metres) that bordered the Dinaric Carbonate Platform on the west and southwest respectively. This difference confirms the previously proposed interpretation that most of the carbonate production from the Dinaric Carbonate Platform was transported towards the southwest.
Migration Dynamics and Seasonal Variation In the Biometrics of the Eurasian Curlew (Numenius arquata) Migrating through the Lower Vistula Valley (N Poland) in Autumn
Authors: Krupa Robert , Meissner Włodzimierz , Krupa Małgorzata , Sereda Agnieszka 
Published: October 2009

Migration Dynamics and Seasonal Variation In the Biometrics of the Eurasian Curlew (Numenius arquata) Migrating through the Lower Vistula Valley (N Poland) in Autumn
The aim of this study was to present data on the phenology of autumn migration of the Eurasian Curlew passing the lower Vistula valley and to determine whether there is a difference in biometrics between early and late migrants, which may reflect different timing of migration of birds from different parts of the breeding range. Studies were conducted in the lower Vistula valley in 2003-2008. Median date of migration fell into 9-13 August pen-tade. The migration dynamics showed major day-to-day changes in bird numbers and almost all of observed flocks migrated without staying in the study area. Moreover, only one bird was caught twice during the season. It indicates that lower Vistula valley is not an attractive stopover site for Eurasian Curlews. There were significant differences in the total head lengths, bill lengths and body masses of birds caught in different ten-days periods with larger and heavier birds occurring towards the end of the study period (ANOVA, Neuman-Keuls test: p < 0.05 in all cases). The gradual increase in the total head and bill lengths and probably also in body mass indicates that bigger birds from the eastern part of the breeding range migrate later than smaller birds, which breed in the west. There were no significant differences in wing length, tarsus length and tarsus with toe length (ANOVA, Neuman-Keuls test: p > 0.05 in all cases). Subspecies N. a. arquata and N. a. orientalis have similar wing length and in this study there were no significant differences for this measurement between following decades of the studied period. Collected data suggest that the wing length, which had clearly bimodal distribution, should be the best linear measurements for sexing at least juvenile Eurasian Curlews.
Plasma concentrations of generic lopinavir/ritonavir in HIV type-1-infected individuals
Authors: van der Lugt Jasper , Lange Joep , Avihingsanon Anchalee , Ananworanich Jintanat , Sealoo Siriporn , Burger David , Gorowara Meena , Phanuphak Praphan , Ruxrungtham Kiat 
Published: October 2009

Background Generic drugs can contribute to access to treatment for HIV-infected patients. However quality and safety remains an issue of concern. Therefore, we evaluated minimal plasma concentrations and short-term safety of a generic lopinavir/ritonavir 200/50 mg tablet formulation. Methods In a single-centre prospective pilot study, patients receiving protease-inhibitor-based antiretroviral treatment were switched to a generic lopinavir/ritonavir tablet at the standard dose (400/100 mg twice daily). Minimum drug concentrations (Cmin) of lopinavir and ritonavir were performed before switching (in 16 patients who were on Kaletra® soft-gel capsules) and after 4 weeks (in all patients). Plasma levels of lopinavir and ritonavir were determined by a validated HPLC method. Either the Wilcoxon signed-rank or Mann–Whitney U test was used to compare the groups. Results A total of 37 patients (18 females) were included in the study. Two stopped their study medications prematurely because of intolerance. The median (interquartile range) lopinavir Cmin was 7.2 mg/l (5.8–8.3) and no patients had subtherapeutic levels <1.0 mg/l. No significant difference of lopinavir Cmin levels was found between Kaletra®, and the generic product ( P=0.224). By contrast, the Cmin of generic ritonavir was higher ( P=0.012). Food did not affect the drug levels. Mild gastrointestinal complaints were reported in 12 patients. Conclusions The generic lopinavir/ritonavir tablet showed Cmin plasma concentrations similar to what is described for the branded product, with good stability, independent of food intake. These data support the efforts in scaling up access to generic second-line treatment in middle- and low-income countries.
Une économie salafie de la prière dans la région du Balé en Éthiopie
Authors: Østebø Terje 
Published: October 2009

Résumé Cet article est consacré aux processus de transformation religieuse et au développement d’une économie de la prière salafie dans la localité de Balé en Éthiopie. En observant l’évolution de ce mouvement des années 1960 à nos jours, l’article révèle la corrélation existant entre la poursuite de la réforme religieuse d’une part et la modification des structures socio-économiques et l’émergence de nouveaux schémas d’échanges translocaux d’autre part. Partant d’une description de l’économie de la prière traditionnelle en pays oromo, il étudie l’incidence de la mutation des structures socio-économiques sur ces pratiques. Il se penche aussi sur la fragmentation du salafisme à Balé et sur l’émergence du mouvement Ahl al-Sounna.
Entrepreneurs moraux et réseaux financiers islamiques en Mauritanie
Authors: Bah Mohamed Fall Ould 
Published: October 2009

Résumé Ce texte s’intéresse à la manière dont, dans la société maure de Mauritanie, les entrepreneurs moraux se sont efforcés de se brancher sur les circuits de la finance islamique globale, apparue au début des années 1970. Après avoir jeté un éclairage sur la place des groupes engagés dans ce processus au sein des structures sociales maures traditionnelles, les auteurs abordent, à partir de quelques exemples, la constitution et l’évolution des dispositifs financiers mauritaniens dans leurs rapports avec les circuits financiers islamiques globaux, ainsi que les personnalités et réseaux locaux qui les animent, généralement liés à la mouvance des Frères musulmans.
Fissabilillah ! Islam au Sénégal et initiatives féminines
Authors: Hardy Ferdaous , Semin Jeanne 
Published: October 2009

Résumé Cette étude analyse l’économie morale du pèlerinage à La Mecque qui semble devenir un nouveau domaine de prédilection pour les femmes sénégalaises. L’étude se penche sur la façon dont les femmes se sont approprié le pèlerinage en réhabilitant le principe du « retour à l’envoyeur » qu’elles combinent au discours très fort de l’islam sur la charité pour organiser et financer leur voyage religieux. Ainsi, cet article alimente la réflexion sur le concept d’économie morale comme système de normes et de valeurs influençant la formation des réseaux qui constituent la sphère économique.
Économie morale, islam et pouvoir charismatique au Burkina Faso
Authors: Vitale Mara 
Published: October 2009

Résumé Cet article essaie de définir le concept d’économie morale, d’abord dans le cadre général de la littérature existante, et ensuite dans le cas plus spécifique de l’islam burkinabé. Il analyse les rapports existant entre l’économie morale et les figures charismatiques de l’islam au Burkina Faso. L’exemple de deux chefs religieux inscrits dans des contextes différents – urbain et rural – aide à comprendre comment les autorités charismatiques gèrent les biens économiques qui leur sont confiés par les fidèles, dans l’intérêt de la communauté. L’article a aussi l’ambition de comprendre quelles stratégies ces « planificateurs sociaux » mettent en place afin de mobiliser et investir les ressources engendrées par les flux migratoires.
Prolégomènes : au commencement du travail psychique
Authors: Herlem Pascal 
Published: October 2009

Résumé Le propos de ce texte est d’aborder le « travail » selon deux points de vue articulés entre eux, celui de l’étymologie du mot « travail » lui-même et celui de la transmission à l’infans, par la mère, de la nécessité du travail psychique. À la notion de commencement s’intègre celle de transmission pour amener à la conception du « commencement de la transmission ». La mémoire de la langue suggère que ce commencement se fait plutôt dans la peine, mais les théorisations de Piera Aulagnier introduisent les notions de rencontre de deux psychés, celle de la mère et celle de l’infans, pour un travail commun, de telle sorte que la solitude de l’infans ne peut se concevoir autrement que pensée et travaillée par l’autre.
Chaos et travail psychique
Authors: Bugglin Élisabeth 
Published: October 2009

Résumé Nous proposons un modèle à visée épistémologique de construction métapsychologique qui s’appuie sur certains apports de la physique quantique et notamment sur la théorisation du modèle du chaos. En supposant que l’espace psychique de l’infans est un espace inorganisé qui se caractérise par un potentiel non encore utilisé de significations, nous tâcherons d’imaginer les processus psychiques et conditions environnementales nécessaires permettant l’attribution du sens à ce non-sens initial. Seront établies certaines analogies possibles entre la dynamique des « attracteurs étranges » avec les processus de croissance où se développent à la fois transformation et permanence, ainsi que celles établies avec les mouvements de la vie psychique rendant son évolution tributaire de la temporalité ; ce dernier point mettant ainsi au défi le déterminisme psychique.