A computer technique for predicting smoke movement in tall buildings

An approach to the analysis of stack effect has been developed which allows the prediction of internal air flow quantities and associated pressure differentials for specific buildings prior to construction. An example of the application of this analysis is presented for a hypothetical 75-story office building. Note: The authors presented this paper at a symposium on “The Control of Smoke Movement on Escape Routes in Buildings,” sponsored by the Joint Fire Research Organization and held on April 9 and 10, 1969 in Hertfordshire, England.     

Engineering geology today

Summary The author discusses the development and present state of the engineering geology. He warns the engineering geologists against a merely mechanical approach and emphasizes that an engineer needs to understand geology as well. Further an analysis of the relation between geology and civil engineering and between engineering geology and soil and rock mechanics is presented. Finally the paper deals with the tasks of engineering geology at designing and construction of structures as well as with the problems of education in engineering geology.

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La Géologie De l’Ingénieur Aujourd’Hui

Résumé L’auteur examine la question du développement et de la situation acutelle de la géologie de l’ingénieur. II préviend d’un accès simplement méchanical en accentuant, qu’il est vraiement nécéssaire pour un ingénieur de comprendre aussi la géologie. Puis, l’auteur analyse la rélation entre la géologie et la construction ainsi qu’entre la géologie de l’ingénieur et la mécanique du sol. Enfin, le travail traits les taches de la géologie de l’ingénieur dans la sphère des projets et de la réalisation des constructions ainsi que les problèmes de l’éducation.

     

Controlein situ du compactage de remblais sous eau

Bulletin of Engineering Geology and the Environment - La fermeture de l'Escaut oriental constitute le couronnement des travaux du Plan Delta aux Pays-Bas. Le danger de l'érosion et de...     

Influences of iron, manganese, and dissolved organic carbon on the hypolimnetic cycling of amended mercury

The biogeochemical cycling of iron, manganese, sulfide, and dissolved organic carbon were investigated to provide information on the transport and removal processes that control the bioavailability of isotopic mercury amended to a lake. Lake profiles showed a similar trend of hypolimnetic enrichment of Fe, Mn, DOC, sulfide, and the lake spike ((202)Hg, purity 90.8%) and ambient of pools of total mercury (HgT) and methylmercury (MeHg). Hypolimnetic enrichment of Fe and Mn indicated that reductive mobilization occurred primarily at the sediment-water interface and that Fe and Mn oxides were abundant within the sediments prior to the onset of anoxia. A strong relationship (r(2)=0.986, n=15, p<0.001) between filterable Fe and Mn indicated that reduction of Fe and Mn hydrous oxides in the sediments is a common in-lake source of Fe(II) and Mn(II) to the hypolimnion and that a consistent Mn:Fe mass ratio of 0.05 exists in the lake. A strong linear relationship of both the filterable [Fe] (r(2)=0.966, n=15, p<0.001) and [Mn] (r(2)=0.964, n=15, p<0.001) to [DOC] indicated a close linkage of the cycles of Fe and Mn to DOC. Persistence of iron oxides in anoxic environments suggested that DOC was being co-precipitated with Fe oxide and released into solution by the reductive dissolution of the oxide. The relationship between ambient and lake spike HgT (r(2)=0.920, n=27, p<0.001) and MeHg (r(2)=0.967, n=23, p<0.001) indicated that similar biogeochemical processes control the temporal and spatial distribution in the water column. The larger fraction of MeHg in the lake spike compared to the ambient pool in the hypolimnion suggests that lake spike may be more available for methylation. A linear relationship of DOC to both filterable ambient HgT (r(2)=0.406, n=27, p<0.001) and lake spike HgT (r(2)=0.314, n=15, p=0.002) suggest a role of organic matter in Hg transport and cycling. However, a weak relationship between the ambient and lake spike pools of MeHg to DOC indicated that other processes have a major role in controlling the abundance and distribution of MeHg. Our results suggest that Fe and Mn play important roles in the transport and cycling of ambient and spike HgT and MeHg in the hypolimnion, in part through processes linked to the formation and dissolution of organic matter-containing Fe and Mn hydrous oxides particles.     

The Effect of Energy-Supply and Performance Indicators on the Performance of Traction-Resource Management Centers

Russian Electrical Engineering - This paper presents the results of a study of the effect of the characteristics of the traction power-supply system on the indicator of the energy supply of...     

Test facility for investigation of heat transfer of promising coolants for the nuclear power industry

The results are presented of experimental investigations into liquid metal heat transfer performed by the joint research group consisting of specialist in heat transfer and hydrodynamics from NIU MPEI and JIHT RAS. The program of experiments has been prepared considering the concept of development of the nuclear power industry in Russia. This concept calls for, in addition to extensive application of water-cooled, water-moderated (VVER-type) power reactors and BN-type sodium cooled fast reactors, development of the new generation of BREST-type reactors, fusion power reactors, and thermonuclear neutron sources. The basic coolants for these nuclear power installations will be heavy liquid metals, such as lead and lithium-lead alloy. The team of specialists from NRU MPEI and JIHT RAS commissioned a new RK-3 mercury MHD-test facility. The major components of this test facility are a unique electrical magnet constructed at Budker Nuclear Physics Institute and a pressurized liquid metal circuit. The test facility is designed for investigating upward and downward liquid metal flows in channels of various cross-sections in a transverse magnetic field. A probe procedure will be used for experimental investigation into heat transfer and hydrodynamics as well as for measuring temperature, velocity, and flow parameter fluctuations. It is generally adopted that liquid metals are the best coolants for the Tokamak reactors. However, alternative coolants should be sought for. As an alternative to liquid metal coolants, molten salts, such as fluorides of lithium and beryllium (so-called FLiBes) or fluorides of alkali metals (so-called FLiNaK) doped with uranium fluoride, can be used. That is why the team of specialists from NRU MPEI and JIHT RAS, in parallel with development of a mercury MHD test facility, is designing a test facility for simulating molten salt heat transfer and hydrodynamics. Since development of this test facility requires numerical predictions and verification of numerical codes, all examined configurations of the MHD flow are also investigated numerically.     

Boosting the electrochemical performance of Li-garnet based all-solid-state batteries with Li<Subscript>4</Subscript>Ti<Subscript>5</Subscript>O<Subscript>12</Subscript> electrode: Routes to cheap and large scale ceramic processing

All-solid-state batteries based on fast Li⁺ conducting solid electrolytes such as Li₇La₃Zr₂O₁₂ (LLZO) give perspective on safe, non-inflammable, and temperature tolerant energy storage. Despite the promise, ceramic processing of whole battery assemblies reaching close to theoretical capacities and finding optimal strategies to process large-scale and low cost battery cells remains a challenge. Here, we tackle these issues and report on a solid-state battery cell composed of Li₄Ti₅O₁₂ / c-Li_6.25Al_0.25La₃Zr₂O₁₂ / metallic Li delivering capacities around 70–75 Ah/kg with reversible cycling at a rate of 8 A/kg (for 2.5–1.0 V, 95 °C). A key aspect towards the increase in capacity and Li⁺ transfer at the solid electrolyte-electrode interface is found to be the intimate embedding of grains and their connectivity, which can be implemented by the isostatic pressing of cells during their preparation. We suggest that simple adaption of ceramic processing, such as the applied pressure during processing, strongly alters the electrochemical performance by assuring good grain contacts at the electrolyte-electrode interface. Among the garnet-type all-solid-state ceramic battery assemblies in the field, considerably improved capacities and cycling properties are demonstrated for Li₄Ti₅O₁₂ / c-Li_6.25Al_0.25La₃Zr₂O₁₂ / metallic Li pressed cells, giving new perspectives on cheap ceramic processing and up-scalable garnet-based all-solid-state batteries.     

Subcontracting in project-based firms: Do you follow the same pattern across your different projects?

This article analyzes an important dimension in which the organization of the projects performed by the same firm can differ: the insourcing or outsourcing of an activity that needs to be undertaken in each of the different projects. Analyzing the variability of a firm's insourcing or outsourcing decision across its projects gives us a better understanding of the firm's decision-making process in terms of the stability of its choices across projects and the main determinants of that variability. This analysis is valuable because a firm that manages multiple projects can benefit from the careful analysis and consideration of the interactions among and the specificities of its projects. Using a comprehensive database of construction firms and projects, we conclude that firms demonstrate variability in their insource or outsource choices across projects and that this variability is explained by factors such as the number of projects simultaneously undertaken, the variability in a project's complexity, and their market power in local markets. These results suggest that the theories explaining firm boundaries in project-based firms should be expanded to include interrelationships between projects and the individual project characteristics that drive differences in insource or outsource choices.