995 resultados para 204-1246


Relevância:

10.00% 10.00%

Publicador:

Resumo:

In the markets-as-networks approach business networks are conceived as dynamic actor structures, giving focus to exchange relationships and actors’ capabilities to control and co-ordinate activities and resources. Researchers have shared an understanding that actors’ actions are crucial for the development of business networks and for network dynamics. However, researchers have mainly studied firms as business actors and excluded individuals, although both firms and individuals can be seen as business actors. This focus on firms as business actors has resulted in a paucity of research on human action and the exchange of intangible resources in business networks, e.g. social exchange between individuals in social networks. Consequently, the current conception of business networks fails to appreciate the richness of business actors, the human character of business action and the import of social action in business networks. The central assumption in this study is that business actors are multidimensional and that their specific constitution in any given situation is determined by human interaction in social networks. Multidimensionality is presented as a concept for exploring how business actors act in different situations and how actors simultaneously manage multiple identities: individual, organisational, professional, business and network identities. The study presents a model that describes the multidimensionality of actors in business networks and conceptualises the connection between social exchange and human action in business networks. Empirically the study explores the change that has taken place in pharmaceutical retailing in Finland during recent years. The phenomenon of emerging pharmacy networks is highly contemporary in the Nordic countries, where the traditional license-based pharmacy business is changing. The study analyses the development of two Finnish pharmacy chains, one integrated and one voluntary chain, and the network structures and dynamics in them. Social Network Analysis is applied to explore the social structures within the pharmacy networks. The study shows that emerging pharmacy networks are multifaceted phenomena where political, economic, social, cultural, and historical elements together contribute to the observed changes. Individuals have always been strongly present in the pharmacy business and the development of pharmacy networks provides an interesting example of human actors’ influence in the development of business networks. The dynamics or forces driving the network development can be linked to actors’ own economic and social motives for developing the business. The study highlights the central role of individuals and social networks in the development of the two studied pharmacy networks. The relation between individuals and social networks is reciprocal. The social context of every individual enables multidimensional business actors. The mix of various identities, both individual and collective identities, is an important part of network dynamics. Social networks in pharmacy networks create a platform for exchange and social action, and social networks enable and support business network development.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The present work gives a comprehensive numerical study of the evolution and decay of cylindrical and spherical nonlinear acoustic waves generated by a sinusoidal source. Using pseudospectral and predictor–corrector implicit finite difference methods, we first reproduced the known analytic results of the plane harmonic problem to a high degree of accuracy. The non-planar harmonic problems, for which the amplitude decay is faster than that for the planar case, are then treated. The results are correlated with the known asymptotic results of Scott (1981) and Enflo (1985). The constant in the old-age formula for the cylindrical canonical problem is found to be 1.85 which is rather close to 2, ‘estimated’ analytically by Enflo. The old-age solutions exhibiting strict symmetry about the maximum are recovered; these provide an excellent analytic check on the numerical solutions. The evolution of the waves for different source geometries is depicted graphically.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The molecular and crystal structures of 4-ethynylcyanobenzene arereported. The packing of molecules in the crystal is found to be homologous with the crystal structures of HCN, cyanoacetylene and 4-cyano-4'-ethynylbiphenyl. Alternatively, these four crystals could be said to constitute a structural homologous series. The influence of C-H center dot center dot center dot N hydrogen bonding in directing a linear supramolecular arrangement of molecules with ethynyl and cyano groups at opposite ends, is illustrated. (C) 2010 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A solid solution of the type Ba5x/2Bi(1-x)5/3Nb5O15 has been identified in the BaO-Bi2O3-Nb2O5 system for the first time. The limits of the solid solution are within the range 0.52 <= x <= 0.80. The compositions x = 0.52, 0.60, 0.72, 0.77, 0.78, and 0.80 were synthesized by the solid-state technique from the starting materials in stoichiometric quantities. The powder X-ray patterns of all the phases in the domain indicate a structural similarity to tetragonal tungsten bronzes (TTBs). The compositions below x = 0.52 and those above x = 0.80 exhibit barium niobate and bismuth niobate impurities, respectively. Single crystals of the composition x = 0.77 were obtained by the melt cooling technique. The crystal structure of Ba3.85/2Bi1.15/3Nb5O15 (x = 0.77) was solved in the tetragonal space group P4bm (No. 100) with a = 12.4938 (14) angstrom, c = 3.9519 (2) A, V = 616.87 (10) angstrom(3), and Z = 2 and was refined to an R index of 0.034. Dielectric measurements on all the phases indicate a typical relaxor behavior with a broad phase transition at T-m approximate to 300 K.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The fungicide Bavistin was assessed for mutagenic potential by various assays. Bavistin was found to be unable to induce gene mutation in Salmonella typhimurium, but it was able to induce transfection inhibition in Mycobacterium smegmatis. Bavistin was able to induce immediate genotoxic effects in plants but these were not carried through in development as in the long term no genotoxic effects were observed by the progeny test. Bavistin did induce micronuclei formation and did cause an increase in the ratio of normochromatic to polychromatic erythrocytes in mice. It was able to induce a very low frequency of sister-chromatid exchange in human lymphocytes and in addition, it was observed that the chemical affected the mitotic index but did not affect the cell cycle duration. Present studies indicate that the pesticide shows a positive response in 4 out of 5 different test systems (Table 8) and most of the observations support that Bavistin is genotoxic.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

C~HaO 4, Mr=204.2, monoclinic, P2Jn,a=3.900(1), =37.530(6), c=6.460(1)A, fl=103.7 (1) °, V= 918.5 (5) A 3, Z = 4, D m = 1.443, D x --- 1.476 Mg m -3, Cu Ks, 2 = 1.5418 ,/k, /t = 0.86 mm -~, F(000) = 424, T= 293 K, R = 0.075 for 1019 significant reflections. Molecules pack in fl-type stacking mode which is characterized by the close packing of parallel and nearly planar reactive double bonds with a separation of 3.900/~ along the a axis.The syn head-head dimer obtained is the direct consequence of this packing arrangement. Molecular packing is stabilized by intermolecular C-H...O hydrogen bonding. Analysis of acetoxy...acetoxy interactions in the acetoxy compounds retrieved from the Cambridge Structural Database reveal that the majority of them are anti-dipolar.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In Salmonella typhimurium, propionate is oxidized to pyruvate via the 2-methylcitric acid cycle. The last step of this cycle, the cleavage of 2-methylisocitrate to succinate and pyruvate, is catalysed by 2-methylisocitrate lyase (EC 4.1.3.30). Methylisocitrate lyase (molecular weight 32 kDa) with a C-terminal polyhistidine affinity tag has been cloned and overexpressed in Escherichia coli and purified and crystallized under different conditions using the hanging-drop vapour-diffusion technique. Crystals belong to the orthogonal space group P2(1)2(1)2(1), with unit-cell parameters a = 63.600, b = 100.670, c = 204.745 Angstrom. A complete data set to 2.5 Angstrom resolution has been collected using an image-plate detector system mounted on a rotating-anode X-ray generator.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This work offers a method for finding some exact soliton solutions to coupled relativistic scalar field theories in 1+1 dimensions. The method can yield static solutions as well as quasistatic "charged" solutions for a variety of Lagrangians. Explicit solutions are derived as examples. A particularly interesting class of solutions is nontopological without being either charged or time dependent.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A performance prediction procedure is presented for low specific speed submersible pumps with a review of loss models given in the literature. Most of the loss theories discussed in this paper are one dimensional and improvements are made with good empiricism for the prediction to cover the entire range of operation of the low specific speed pumps. Loss correlations, particularly in the low flow range, are discussed. Prediction of the shape of efficiency-capacity and total head-capacity curves agrees well with the experimental results in almost the full range of operating conditions. The approach adopted in the present analysis, of estimating the losses in the individual components of a pump, provides means for improving the performance and identifying the problem areas in existing designs of the pumps. The investigation also provides a basis for selection of parameters for the optimal design of the pumps in which the maximum efficiency is an important design parameter. The scope for improvement in the prediction procedure with the nature of flow phenomena in the low flow region has been discussed in detail.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Tutkimus käsittelee keskiajan suurinta harhaoppia katarismia Toulousin hiippakunnassa 1200-luvun ensimmäisellä puoliskolla. Tarkempi tutkimusalue on Lauragaisin maaseutu Toulousin ja Carcassonnen välissä. Alue oli Etelä-Ranskan katarismin sydänaluetta. Tutkimus käy läpi katarismin historian vuosina 1200 1245. Tuolloin se muuttui julkisesti siedetystä uskosta salassa harjoitettavaksi harhaopiksi. Erityisessä tarkkailussa ovat Lauragaisin kylät ja niiden asukkaiden suhde katarismiin. Tutkimus selvittää miten kiellettyihin kataarien tapaamisiin osallistuttiin Lauragaisissa ja kuinka suuri osa alueen väestöstä uskoi katarismiin. Tutkimus pohjautuu pitkälti Bernard de Caux n vuosien 1245 1246 inkvisition kuulustelujen rekisteriin, joka sisältää 5 471 lauragaisilaisen inkvisitiotunnustusen. Tarkempaan tarkasteluun on valittu seitsemän kylää ja niiden 1 069 inkvisitiotunnustusta. Niiden sisältämät tiedot on syötetty tutkimuksen apuna toimivaan relaatiotietokantaan. Kylien asukkaiden kuulusteluja on verrattu keskenään tietokannan avulla. Kuulustelujen perusteella on rekonstruoitu kataarien tapaamisia vuosina 1195 1245. Lisäksi tutkitaan tarkemmin katarismin toiminnan kannalta tärkeitä mekanismeja Saint-Martin-Lalanden kylässä. Tutkimuksen mukaan katarismi vetosi kaikkiin yhteiskuntaluokkiin kuuluneisiin ihmisiin. Sukusiteillä ja Lauragaisin kylien asukkaiden keskinäisellä solidaarisuudella oli suuri merkitys katarismin säilymisessä, kun harhaoppi yritettiin tukahduttaa. Inkvisitiot onnistuivat murtamaan kylien sisäisen solidaarisuuden 1240-luvulla. Tutkimuksen keskeisin tulos on arvion esittäminen katarismiin uskoneiden maallikoiden lukumäärästä. Noin kymmenesosa Lauragaisin aikuisväestöstä oli aktiivisia kataariuskovia. Jopa kaksi viidesosaa alueen asukkaista oli jossain elämänsä vaiheessa osallistunut kataarien kiellettyihin uskonnollisiin tilaisuuksiin. Katarismiin uskoneiden ja siihen kosketuksissa olleiden ihmisten määrä on keskeinen tieto, kun arvioidaan katolisen kirkon harhaopin vastaisia toimia. Katarismin tuhoamiseksi julistettiin 20 vuotta kestänyt ristiretki. Inkvisitiolta kului sen jälkeen vielä 90 vuotta katarismin tuhoamiseen. Katarismi oli merkittävä harhaoppi, koska se vetosi kiellettynäkin huomattavaan osaan Lauragaisin väestöstä.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The oil phase, in an oil-in-water emulsion on a steel substrate, is strongly repelled by the substrate. The oil in this situation does not wet the steel and steel/steel friction is high. In this work we disperse anionic surfactants in an oil film and study the effect of this dispersion on the force of interaction between a silica colloid probe (AFM) carrying the oil film and a steel substrate in water. It is observed that when the surfactant is oil insoluble and the interaction time is short the strong entropic repulsion (without the surfactant) is replaced by a strong attraction. The steel on steel sliding friction in this case is low compared to that what is achieved when the surfactant is soluble in oil. The rationale underlying these interactions is explored here. (C) 2011 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Synchrotron-based X-ray diffraction was used to study the phase diagrams and determine the compressibilities of the pyrochlore rare-earth titanates Ho2Ti2O7, Y2Ti2O7 and Tb2Ti2O7 to 50GPa. The bulk moduli of the cubic phase of these materials were calculated to be 213 +/- 2, 204 +/- 3 and 199 +/- 1GPa, respectively. The onset of a structural phase change from cubic to monoclinic was observed near 37, 42 and 39GPa, respectively. The bulk modulus for the high pressure monoclinic phase of Y2Ti2O7 has been determined to be 185 +/- 3GPa.