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Comparisons and modelling of primary vacuum standardsMusic, Vesna January 1999 (has links)
No description available.
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Panemunės inžinerinės-geologinės sąlygos. Statinio bei dinaminio zondavimo tyrimo rezultatų analizė / Engineering-Geologic conditions in panemunė. analysis of results of static and dynamic probing testsSamuchovas, Andrejus 08 September 2009 (has links)
Santrauka Temos aktualumas. Populiariausias Lietuvoje naudojamas būdas stipruminėms grunto savybėms nustatyti yra statinis zondavimas. Tuo tarpu dinaminis zondavimas naudojamas labai retai, dažniausiai tik ten kur neįmanoma atlikti.statinio zondavimo. Tokia situacija susidarė dėl to, kad Lietuvoje nėra metodikos pamatų skaičiavimams pagal qd (dinaminio zondavimo) reikšmes ir projektuotojai nelabai supranta dinaminio zondavimo privalumų. Esant tokiai padėčiai dauguma inžinerinių geologinių tyrimų įmonių qd reikšmes verčia į statinio zondavimo reikšmes qc, nors perėjimo koeficientų iš qd į qc nėra nurodyta jokiuose inžinerinių tyrinėjimų bei statybos reglamentuose ir žininuose. Dėl to inžinerinės geologijos specialistai dažniausiai naudoja savo pačių išvestus koeficientus. Taigi šiame darbe, atliktų tyrimų dėka, bus bandoma pritaikyti optimaliausius perėjimo koeficientus iš qd ir qc. Norint nustatyti šiuos koeficientus, buvo gilintasi į perėjimo iš dinaminio zondavimo rezultatų į statinio zondavim rezultatus problemas. Darbo tikslas – suteikti informaciją inžinieriams geologams apie dviejų inžinerinių geologinių lauko tyrimų metodų efektyvumą. Uždaviniai: - išbandyti statinį ir dinaminį zondavimą konkrečioje teritorijoje, - palyginti gautus rezultatus, - surasti perėjimo koeficientus iš qd į qc. Pirmoje darbo dalyje autorius aprašo tyrimo objekto inžinerinės geologinės sąlygas Antroje dalyje STATINIO IR DINAMINIO ZONDAVIMO REZULTATŲ GRUNTŲ ANALIZĖ Trečioje dalyje gautų... [toliau žr. visą tekstą] / SUMMARY Relevance of the topic. The most popular method of the determination of soil resistance is the static probing test. Meanwhile, the dynamic probing test is applied very rarely, mainly in places where the static probing test may not be used. Such situation has occurred because of the lack of methodology base for calculations according to qd (dynamic probing) values in Lithuania, while the designers do not perceive the advantages of dynamic probing. In the present situation, most of the engineering geology testing companies translate qd values into static probing values qc, though coefficients of conversion from qd to qc are not given in any engineering survey or construction regulations or references. Therefore, experts of engineering geology mostly use their own derived coefficients. Thus, through performed tests, the most optimal coefficients of conversion from qd to qc shall be applied in this paper. In order to determine these coefficients, problems of conversion from dynamic probing results to static probing results were analysed. The goal of the paper is to provide information for engineers geologists on the efficiency of two methods of engineering geologic field tests. Tasks: - Testing of static and dynamic probing in a specific territory; - Comparison of received results; - Finding of coefficients of conversion from qd to qc. The first part of the paper describes the engineering geologic conditions of the testing object. The second part analyses the results of... [to full text]
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Static and dynamic light scattering of high molecular weight polystyrene in good solventsSaeed, Akhtar January 1991 (has links)
No description available.
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Effect of Floor Slabs and Floor Beams on Static and Dynamic Behaviour of Shear Wall StructuresBiswas, Jayanta K. 11 1900 (has links)
<p>This thesis studies the effect of-floor slabs on the static and dynamic behaviour of the shear wall structure. A single component has been analysed using the 'Matrix Transfer' technique along with Vlaspv's thin walled elastic beam theory. Experimental verification was done on a small scale plexiglas eight storey model in the form of a channel section for both static and dynamic loading. The thesis also deals with the ·analysis of the nonplanar shear walls coupled through floor beams subjected to static loading. The continuum approach along with Vlasov's theory h&s been used in the analysis. Experimental verification was done on a small scale plexiglas model in the form of two equal angles connected by eight floor beams at equal spacing.</p> / Thesis / Master of Engineering (ME)
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Incorporating external effects in economic evaluation : the case of smokingTrapero-Bertram, Marta January 2011 (has links)
The aim of this thesis is to explore methods to incorporate external effects on decision making of public health programmes in a UK setting, using smoking cessation as an example. The National Institute for Health and Clinical Excellence (NICE) methodological guidance for evaluating public health programmes is missing the incorporation of external effects. Therefore there is a need for considering their incorporation in such evaluations and to assess what are the appropiate methods to do so. Smoking cessation is an example where epidemiological evidence of external effects exists but has not generally been incorporated into economic evaluation. This thesis therefore focused in measuring the impact, in terms of costs and QALYs lost, of the incorporation of passive smoking, smoking during pregnancy and transmission of smoking behavior into economic evaluation of smoking cessation programmes previously developed to inform policy. A static Markov model is used to incorporate passive smoking and smoking during pregnancy, whereas transmisison of smoking behaviour is incorporated through a dynamic model. The findings show that some external effects can be incorporated without a system dynamic model, when this does occur, a static Markov model may be used to account for external effects in economic evaluation. Sometimes, to incorporate external effects, the model needs a change of population. Because smoking cessation interventions are generally highly cost-effective, the incorporation of external effects does not appear to change policy decisions, but there is a clear impact on the magnitude of the ICER. Passive smoking and smoking during pregnancy have higher impact in terms of costs and QALYs lost than transmission of smoking behaviour. Our discussion considers the validity of the methods used; how much the decision making process would be affected considering or not external effects on economic evaluation of smoking cessation interventions; and other valuation approaches for external effects, such as contingent valuation.
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Static and dynamic response of sandstone masonry units bound with fibre reinforced mortarsIslam, Md Toihidul Unknown Date
No description available.
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Static and dynamic response of sandstone masonry units bound with fibre reinforced mortarsIslam, Md Toihidul 11 1900 (has links)
This research project describes the impact resistance of masonry units bound with fibre-reinforced Type S mortars and hydraulic lime mortar. The dynamic impact factor and stress rate sensitivity were evaluated for the flexural strength of the mortar and the bond strength, and further, the pattern of failure was noted for each mix and loading rate. Results show that the impact resistance of the masonry units increased in the presence of fibres. However, the stress rate sensitivity of the bond strength decreased with an increase in fibre content. Also, whereas the mode of failure in those masonry units bound with plain Type S mortars was through fracture at the mortar-block interface, the addition of fibres transferred the failure plane to within the masonry block. For hydraulic lime mortar, fibre reinforcement retained the sacrificial nature of mortar and also increased the flexural toughness factor of the joint even under dynamic loading. / Structural Engineering
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On structural studies of high-density potassium and sodiumMcBride, Emma Elizabeth January 2014 (has links)
The alkali elements at ambient conditions are well described by the nearly-free electron (NFE) model, yet show a remarkable departure from this “simple” behaviour with increasing pressure. Low-symmetry complex structures are observed in all, and anomalous melting has been observed in lithium (Li), sodium (Na), rubidium (Rb), and caesium (Cs). In this Thesis, static and dynamic compression techniques have been used to investigate the high-pressure high-temperature behaviour of the alkali elements potassium (K) and Na. Utilising diamond anvil pressure cells and external resistive heating, both in-air and in-vacuum, the melting curve of K has been determined to 24 GPa and 750 K, and is found to be remarkably similar to that of Na, but strikingly different to that reported previously. Furthermore, there is some evidence to suggest that a change in the compressibility of liquid-K occurs at lower pressures than the solid-solid phase transitions, perhaps indicating structural transitions occurring in the liquid phase, similar to those in the underlying solid. This could suggest a mechanism to explain the anomalous melting behaviour observed. Previous ab initio computational studies indicate that the unusual melting curve of Na arises due to structural and electronic transitions occurring in the liquid, mirroring those found in the underlying solid at higher pressures. The discovery that the melting curve of K is very similar to that of Na suggests that the same physical phenomena predicted for Na could be responsible for the high-pressure melting behaviour observed in K. The tI19 phase of K, observed above 20 GPa at 300 K, is a composite incommensurate host-guest structure consisting of 1D chains of guest atoms surrounded by a tetragonal host framework. Along the unique c-axis, the host and guest are incommensurate with each other. During the melting studies described above, it was observed that with increasing temperature, the weaker-bonded guest chains become more disordered while the host structure remains unchanged. To investigate and characterise this order-disorder transition, in situ synchrotron X-ray diffraction studies were conducted on single-crystal and quasi-single crystal samples of tI19-K. An order-disorder phase line has been mapped out to 50 GPa and 650 K. Perhaps the most striking departure from NFE behaviour in the alkali elements is observed in Na at pressures above 200 GPa where it transforms to a transparent electrical insulator. This phase is a so-called elemental “electride”, which may be thought of as being pseudo-ionically bonded. Electrides are predicted to exist in many elements, but at pressures far beyond the current capabilities of static pressure techniques. Utilising laser-driven quasi-isentropic compression techniques, dynamic compression experiments were performed on Na to see if it is possible to observe this electride phase under the timescales of dynamic compression experiment (ns). Optical velocimetry and reflectivity of the sample were measured directly to determine pressure and monitor the on-set of the transparent phase, respectively.
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Dynamic Spillovers between Commodity and Currency MarketsAntonakakis, Nikolaos, Kizys, Renatas 01 March 2015 (has links) (PDF)
In this study, we examine the dynamic link between returns and volatility of commodities and currency markets. Based on weekly data over the period from January 6, 1987 to July 22, 2014, we find the following empirical regularities. First, our results suggest that the information contents of gold, silver, platinum, and the CHF/USD and GBP/USD exchange rates can help improve forecast accuracy of returns and volatilities of palladium, crude oil and the EUR/CHF and GBP/USD exchange rates. Second, gold (CHF/USD) is the dominant commodity (currency) transmitter of return and volatility spillovers to the remaining assets in our model. Third, the analysis of dynamic spillovers shows time{ and event{specific patterns. For instance, the dynamic spillover effects originating in gold and silver (platinum) returns and volatility intensified (degraded) in the period marked by the global financial crisis. After the global financial crisis, the net transmitting role of gold and silver (platinum) returns shocks weakened (strengthened), while the net transmitting role of gold, silver and platinum volatility shocks remained relatively high. Overall, our findings reveal that, while the static analysis clearly classifies the aforementioned variables into net transmitters and net receivers, the dynamic analysis denotes episodes wherein the role of transmitters and receivers of return (volatility) spillovers can be interrupted or even reversed. Hence, even if certain commonalities prevail in each identified category of commodities, such commonalities are time - and event - dependent. (authors' abstract)
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NEW ULTRA-LIGHTWEIGHT STIFF PANELS FOR SPACE APERTURESBlack, Jonathan T. 01 January 2006 (has links)
Stiff, ultra-lightweight thermal-formed polyimide panels considered in this dissertation are examples of next generation gossamer structures that resolve some of the technology barriers of previous, membrane-dominated gossamer designs while maintaining their low mass and low stowage volume characteristics. The research involved statically and dynamically characterizing and modeling several of these panels to develop validated computer models which can be used to determine the effects of changing manufacturing parameters and scalability. Static characterization showed substantial local nonlinear behavior that was replicated by new physics-based finite element models, and global linear bending behavior that was modeled using classical shell finite elements incorporating effective properties in place of bulk material properties to represent the unique stiffening structure of these panels. Dynamic characterization was performed on individual panels using standard impact hammer and accelerometer testing, enabling successful extraction of several structural natural frequencies and mode shapes. Additionally, the three dimensional time history of the surface of the panels was rendered from video data, and temporal filters were applied to the data to examine the frequency content. These data were also correlated to the shell element numerical models. Overall, the research contributes to the total knowledge base of gossamer technologies, advances stiff panel-based structures toward space qualification, and demonstrates their potential for use in apertures and other spacecraft.
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