546 research outputs found
Sultanov T.I. Historiography of the Ethnic and Political History of the Jochid and Chaghataid Uluses
No full textObjective: The article is dedicated to basic stages of ethnic and political development of two heirs of the Mongol Empire – uluses of Jochi (Golden Horde) and Chaghatai (in Central Asia) and their own successors in the 13th–18th cc.
Research materials: The sources mainly used in this study are historical works of contemporary Islamic authors: Jamal Qarshi, Rashid al-Din, Wassaf (turn of the 13th–14th cc.), al-Omari and Hamdallah Qazwini (14th c.), Mirza Muhammad Haydar, Seyfi Çelebi, Amin b. Ahmad Razi (16th c.), Abu-l-Ghazi, Mahmud b. Wali, Hajji Khalifa (17th c.) and others. Also opinions of leading Soviet and post-Soviet as well as foreign specialists on ethnical and political history of Central Asia (V. Barthold, A. Samoilovich, S. Ibragimov, A. Mokeev, B. Karmysheva, Sh. Ando, B.F. Manz, etc.) have been taken into consideration in this study.
Results and novelty of the research: The “reference point” of this article is epoch of Mongol invasions and establishment of the Mongol Empire. During this time earlier political and ethnical realities were crushed. Disintegration of the Empire and creation of independent Chinggisid states initiated new turn of ethno- and politogenesis continued until the fall of these states at the beginning of the 16th c.
Thus, ethnical and political development of the Central Eurasia was a long-term process, and firstly the terms, which are used as ethnonyms today, reflected political and social but not a national characteristics of their holders. Only after disintegration of Chinggisid uluses of imperial type and appearance of new states (Kazakh khanate, Shibanid states on the territory of Chaghataid ulus, Moghulistan and Moghulia-Kashgaria in the Eastern Turkestan) we could talk about formation of ethnical formations, which became a basis for the modern peoples of the Central Asia.
Author pays attention to hypothetical nature of many conclusions of specialist in the ethnical history of Eurasia although they based on careful study of medieval sources. This gives an opportunity to continue researches of this subject
Use of the Genealogical Sorting Index (GSI) to delineate species boundaries in the Neofusicoccum parvum-Neofusicoccum ribis species complex
No full textNeofusicoccum is a recently described genus of common endophytes and pathogens of woody hosts, previously placed in the genus Botryosphaeria. Many morphological characteristics routinely used to describe species overlap in Neofusicoccum, and prior to the use of molecular phylogenetics, isolates from different hosts and locations were often misidentified. Two cryptic species Neofusicoccum ribis and Neofusicoccum parvum were initially described from different continents and recently another four species within this complex were described using fixed nucleotide polymorphisms for differentiation. In a survey of eucalypt cankers in eastern Australia, a collection of morphologically similar Neofusicoccum isolates were obtained. This collection was analysed within the framework of the morphological (MSRC), ecological (ESRC) and phylogenetic (PSRC) species recognition concepts. Morphological data based on spore measurements (MSRC), together with pathogenicity trials (ESRC) were considered alongside molecular analysis (PSRC), which included multiple gene phylogenies constructed from four nuclear gene regions. We also used the Genealogical Sorting Index method to provide objective evidence for the status of terminal taxa in the phylogenetic analysis. The isolates examined exhibited overlapping morphological and culture characteristics, similar pathogenicity to excised stems and shared hosts within the same locations. Phylogenetic analysis separated isolates into 8 clades corresponding to six described species: N. ribis, N. parvum, Neofusicoccum kwambonambiense, Neofusicoccum cordaticola, Neofusicoccum umdonicola, Neofusicoccum batangarum, and two new species. GSI support indicated combined phylogenetic data were monophyletic for all clades and all p-values were significant allowing us to reject the null hypothesis that all groups were from a single mixed group. Consequently the description of Neofusicoccum occulatum is presented
Fatigue Analysis of the Column-Pontoon Connection in a Semi-Submersible Floating Wind Turbine
No full textMotivated by the exciting potential of the new floating offshore wind concepts, this thesis aims to analyze the fatigue behavior of a novel semi-submersible floating offshore wind turbine, developed at CeSOS, NTNU, which consists of four cylindrical columns with one central column supporting the 5 MW NREL wind turbine. The geometry was proposed by the author, based on logic, mathematical derivations, as well as information from the literature. The SESAM package provided by DNV was used for this thesis, including GeniE, Sestra, Submod, SESAM Manager and Xtract. The geometry was developed in the FEM software GeniE, which uses Sestra as solver, while the rest of the tools were utilized for the sub-modeling technique. Two different geometries of the column-pontoon connection were designed and their performances under different loads were analyzed and compared. The model which appeared to be more reliable regarding fatigue was further investigated and optimized in order to reduce the SCF, which are of great importance for fatigue predictions. One crucial hot spot underwent a detailed stress analysis, using the sub-modeling technique, i.e. cutting the structure at a specified location and refining the mesh. The stress assessment at the location of interest was performed in Xtract, and for further extrapolation of the stress results in order to compute the hot spot stresses and the SCFs, an Excel spreadsheet was used. Using the load time series from the dynamic analysis of the global model, and combining them with the hot spot stresses, the stress time series were output for a certain sea state. The actual fatigue calculations were performed in Matlab, using the freely available WAFO package. First, the well-established uni-axial fatigue case was performed, utilizing the rainflow counting method, a proper S-N curve and the Miner's rule. A number of 13 sea states with 10 seeds each, with aligned wind and wave were considered. The fatigue assessment was performed for four different sea headings with respect to the pontoon's direction, i.e. 0, 30, 60 and 90 degrees. Next, an approach for considering multi-axial effects in fatigue analysis was proposed, combining two recently developed methods, Equilibrium Equivalent Structural Stress and the Path-Dependent Maximum Range. Considerations on the importance of multi-axial effects on the analyzed structure were further made, followed by conclusions and recommendations for future work.EWEM European Wind Energy Master - Offshore Engineering trackOffshore and DredgingMechanical, Maritime and Materials Engineerin
Multirate multi-user detectors for wideband code division multiple access
No full textElectrical Engineering, Mathematics and Computer Scienc
Quasi-steady modelling and asymptotic analysis of aeroelastic oscillators
No full textMechanical Maritime and Materials Engineerin
Perlite for permanent confinement of cesium
No full textWe present the potential use of expanded perlite, a metastable amorphous hydrated aluminium silicate, as a permanent medium for the long-term confinement of cesium. The method requires simply a loading by mixing an aqueous cesium nitrate solution and expanded perlite at 300 K followed by densification by sintering. The formation of pollucite, CsAlSi2O6, a naturally occurring mineral phase, upon careful heat treatment is demonstrated by X-ray diffraction. Leaching tests on the resulting glass-ceramics reveal a very low Cs departure of 0.5 mg m−2 d−1
Iron Studies in Man using Instrumental Neutron Activation Analysis and Enriched Stable Activable Isotopes
No full textIron is an essential trace element involved in many processes in the human body. Some disorders like iron deficiency anaemia and haemochromatosis directly result from changes in iron status, while on the other hand iron metabolism changes during illness. Since these adjustments in the iron handling of the body may have consequences for the clinical outcome and treatment of patients, a reliable and accurate test to measure iron concentrations and to study iron metabolism in normal and pathological conditions is required. A number of studies in this thesis demonstrate that instrumental neutron activation analysis (INAA) is an adequate method to measure even low concentrations of iron reliably not only in blood, but also in urine, faeces and red blood cells. A great advantage of this technique in contrast to techniques such as mass spectrometry is, that materials in which iron should be measured, hardly need preparation before measurement. It is even possible to measure iron concentrations in complete meals without the need to take small samples. INAA is also able to measure low concentrations of an enriched stable iron isotope facilitating the use of such an isotope in clinical studies without exposure to radiation. In a first clinical study using INAA it could be demonstrated that Sudanese patients with severe iron deficiency anaemia also have severe zinc deficiency. Since in INAA access to a nuclear reactor facility is necessary, the technique should be considered more suitable for research than for routine use
Management of client requirements for design and build projects in the construction industry of Hong Kong
No full textAuthor name used in this publication: Patrick T.I. Lam2010-2011 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishedGreen (AAM
Risk mitigation strategies for guaranteed maximum price and target cost contracts in construction : a factor analysis approach
No full textAuthor name used in this publication: Patrick T.I. Lam2011-2012 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishedGreen (AAM
Vision-based stabilization of micro quadrotors
No full textOn-board stabilization of quadrotors is often done using an Inertial Measurement Unit (IMU), aided by additional sensors to combat the IMU drift. For example, GPS readings can aid when flying outdoors, or when flying in GPS denied environments, such as indoors, visual information from one or more camera modules can be used. A single downwards facing camera however cannot determine the absolute height of the quadrotor, leaving the results from the Optical Flow (OF) up to scale. To estimate the velocity of the quadrotor an additional range sensor, such as an Ultrasonic Sensor (US), is used to solve this scaling problem.These solutions are difficult to scale down to micro quadrotors as the platform becomes too small to fit and lift additional sensors. Therefore stabilizing a quadrotor with a single camera and IMU only would pave the way for the development of even smaller quadrotors. This master thesis presents an adaptive control strategy to stabilize a micro quadrotor in allthree axes using only an IMU and a monocular camera. This is achieved by extending the stability based approach for a single, vertical, axis by De Croon in Distance estimation with efference copies and optical flow maneuvers: a stability-based strategy[1]. This stability based method ncreases the control gain in the visual feedback loop until the quadrotor detects it is oscillating by detecting that the covariance of the given thrust inputs and the measured divergence passes a threshold. Next the height can be estimated using the predetermined relationship between gain and height at which these self-induced oscillations occur and proper gains can be set for the estimated height. An analysis is done in simulation to present proof of concept of the stabilization method in three axis and to determine the effects of scaling and the effects of varying effective Frames per Second (FPS) caused by computations. It was shown that the adaptive gain strategy can stabilize the simulated quadrotor and prevent it from drifting. Furthermore, the control gains were scaled such that the effects of scaling a quadrotor could be mostly negated, though at about a tenth of the scale the simulated noise had such an influence that the scaled gains could not negate it anymore. Furthermore, the minimum effective FPS required to stabilize an ARDrone 2 was determined to be 15 FPS, and it was shown that an increase in effective FPS aids stabilizing the smaller scale quadrotors that became unstable due to the scaling effects.Furthermore, flights on an Parrot ARDrone 2 and Parrot Bebop are performed to show the usability of this control strategy in real life. It was shown that both quadrotors could achieve stable hover without drifting at multiple heights, using various strategies.<br/
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