898 research outputs found
Self-designing networks and structural influences on safety: Developing a theory on the relation between organizational design and safety in temporary organizations that operate in a dynamic environment
No full textContains fulltext :
178382.pdf (Publisher’s version ) (Open Access)Delft University of Technology, 01 juni 2017Promotores : Ale, B.J.M., Kramer, E.H.213 p
Convergence - related 'dynamic spreading' in a mid-crustal ductile thrust zone: a possible orogenic wedge model.
No full textDeformation in an accretionary melange, Alexander Island, Antarctica
No full textAlexander Island contains several belts of melange in a wide accretionary complex. One melange belt in the northwest of the island incorporates both oceanic and trench-fill material. It evolved by many different deformation mechanisms: dispersed independent particulate flow (IPF) and limited cataclasis at shallow levels; and diffusion mass transfer (DMT) and limited crystal plastic processes at deeper levels. Fluid pressures may have risen due to the subduction of young hot oceanic crust, which probably affected the structural evolution of the region by controlling the strength of the decollement and hence the taper of the accretionary prism
Gas transport properties through intact and fractured Callovo-Oxfordian mudstones
No full textA series of controlled water and gas experiments was undertaken on samples of Callovo-Oxfordian (COx) mudstone using a synthetic fluid and helium gas. Data from this study demonstrate that the advective movement of gas through COx is accompanied by dilation of the original fabric (i.e. the formation of pressure-induced microfissures) at gas pressures significantly below that of the minimum principal stress. Flow occurs through a local network of unstable pathways, the properties of which vary temporally and spatially within the mudstone. The coupling of variables results in the development of significant time-dependent effects affecting many aspects of COx behaviour, from the gas breakthrough time to the control of deformation processes. Variations in gas entry, breakthrough and steady-state pressures may result from the arbitrary nature of the flow pathways and/or microstructural heterogeneity. Under these conditions, the data suggest that gas flow is along pressure-induced preferential pathways, where permeability is a dependent variable related to the number, width and aperture distributions of these features. This has important implications for modelling gas migration through low permeability, clay-rich materials
'She must be a very good novelist':Rereading E.H. Young (1880-1949)
No full textE.H. Young was a popular but reclusive English author who published eleven novels between 1910 and 1947. Beginning with the very successful William (1925). Young focussed on middle-class domesticity. The history of Young's subtly iconoclastic novels is, on the one hand, paradigmatic of women writers between the wars who explored the home, and. on the other, instructive about the complexity and limitations of concepts such as middlebrow, canon formation, taste, and modernity. Reading Young's novels and analyzing their publication hsitory and reception raise intriguing questions concerning the nature of reading pleasure and the continuing wide appeal of novels of the everyday.</p
Use of extension testing to investigate the influence of finite strain on the Theological behaviour of marble
No full textAsfalt in de waterbouw
No full textDit document bevat de vijfde brochure van de Vereniging voor Bitumineuze Werken (VBW) getiteld "Asfalt in de waterbouw". De brochure bevat een achttal artikelen m.b.t. dit onderwerp: - Totstandkoming van de leidraad voor toepassing van asfalt in de waterbouw; voorgeschiedenis, opzet en toekomstig gebruik; door ir. E.H. Ebbens - Overzicht asfalttoepassingen in de waterbouw; door Prof. ir. J.F. Agema - Materiaaltechnologie; door H.J.A.J. Gruis - Ontwerpen van waterbouwkundige asfaltbekledingen; door ir. J.A. van Herpen - Resultaten uit recent onderzoek; door ir. H. Roos - Uitvoering van bitumineuze dijkbekledingen; door ir. G.L.M. Mulders - Bouwen en beheren; door ir. W. Bandsma - Beheer en onderhoud van waterkeringen; door ing. L.A. Philips
First-order phase transitions and giant magnetocaloric effect
No full textModern society relies on cooling technology for food safety, comfort and medical applications. The solid-state cooling technology known as magnetic refrigeration is one of the most promising techniques to replace the current vapor-compression cooling technology. To date, the search for suitable materials with a large magnetocaloric effect (MCE) for domestic applications of magnetic refrigeration is still in progress. This thesis describes a study focused on magnetocaloric materials that can be used in magnetic refrigerators operating at room temperature. Understanding of the phase transition in these materials is of great important to create better materials. As a refrigerator is expected to operate at rather high cycle frequencies, large thermal hysteresis (?Thys) at the magnetic phase transition is the main obstacle to use a material for applications. We have been successful in tuning ?Thys of MnFe(P1-xGex) and related compounds to very small values, while maintaining a large MCE in a large range of working temperatures. These low-cost materials can be used as refrigerants working at high frequencies. This brings the use of practical magnetic cooling a step closer. On the other hand, we have discovered a near room-temperature giant MCE in a new class of magnetic materials based on the intermetallic MnCoGe alloy. The mechanism of manipulating the first-order magnetic phase transition in the MnCoGe-based alloys opens up new possibilities for searching novel magnetic refrigerants for room-temperature applications.Radiation Radionuclides ReactorsApplied Science
Moment formation and giant magnetocaloric effects in hexagonal Mn-Fe-P-Si compounds
No full textLimited resources and the wish for improved prosperity call for efficient use of energy. The UN Advisory Group on Energy and Climate Change recommends a target of 40 % improved efficiency by 2030. Materials research can contribute significantly to reach this target. Magnetic refrigeration offers potential to achieve a 50 % higher energy-efficiency compared to vapor-compression refrigeration. This makes magnetic refrigeration a technology that attracts growing attention. Magnetic refrigeration is based on the magnetocaloric effect, i.e., the temperature change of a magnetic material upon the application or removal of a magnetic field in adiabatic conditions. Magnetocaloric materials play an important role in magnetic refrigeration. Giant magnetocaloric materials which are globally-abundant, non-toxic and can be industrially-mass-produced via a simple fabrication method are particularly attractive for magnetic refrigeration applications. Fe2P-based Mn-Fe-P-Si alloys can meet such requirements. The work presented in this thesis is a study of the magnetocaloric effect and related physical properties in the Mn-Fe-P-Si compounds. Some theoretical aspects of the magnetocaloric effect in general, and the origin of the first-order magneto-elastic transition which enhances the magnetocaloric effect in hexagonal Mn-Fe-P-Si compounds in particular are given in Chapter 2. In Chapter 3, a short review is presented of the experimental techniques and set-ups that have been employed for the sample preparation and the characterization of the physical properties of the Mn-Fe-P-Si compounds. Our efforts to optimize the magnetocaloric effect for refrigeration applications are presented in Chapter 4. We show that a giant magnetocaloric effect and a small thermal hysteresis in Mn-Fe-P-Si compounds of hexagonal Fe2P-type structure can be achieved simultaneously. Furthermore, the working temperature can be controlled over a large interval around room temperature by varying the Mn:Fe and P:Si ratios. In Chapter 5, we report on various types of transition found in (Mn,Fe)1.95P0.50Si0.50 when changing the Mn:Fe ratio. Interestingly, we observe a previously unknown first-order magneto-structural transition and a modified first-order magneto-elastic transition favorable for real refrigeration applications. Using high resolution neutron diffraction, x-ray diffraction and high-temperature magnetic-susceptibility measurements, and based on theoretical calculations, a first-order magneto-elastic transition from high-moment to low-moment in the Mn-Fe-P-Si compounds is presented in Chapter 6. This observation supports our proposal that the competition between moment formation and chemical bonding is at the core of giant magnetocaloric effect displayed in the class of hexagonal Fe2P-based materials with first-order magneto-elastic transition. The effect of the replacement of Fe by Mn on the magnetic moments is also discussed. Chapter 7 is devoted to the effects of P:Si ratio on the magnetic and structural properties of the Mn Fe P Si compounds. In chapter 8, we present magneto-elastic coupling in the Mn-Fe-P-Si compounds. Interestingly, hysteresis and magnetic entropy change are found to be correlated with discontinuous changes of the lattice parameters at the transition temperature. Small thermal hysteresis can be obtained while maintaining the giant magnetocaloric effect. A preliminary comparison of the magneto-elastic coupling and magnetocaloric effect for Mn-Fe-P-As/Ge/Si is also given.Radiation, Radionuclides & ReactorsApplied Science
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