Plasma dynamic synthesis of iron oxides in the «frequency operation» mode of coaxial magnetoplasma accelerator

It is known that the epsilon phase of iron oxide e-Fe2O3 has the highest value of coercive force among all known simple metal oxides (~24 kOe) and is characterized by ferromagnetic resonance in the frequency range from 100 to 200 GHz. The noted features determine the possibility of its wide application. However, there is the problem of synthesis and stabilization this crystal structure at room temperature. In this paper, we consider the possibility to obtain e-Fe2O3 by the plasma dynamic method when the system is operating in the frequency (multi-pulse) regime. The influence of the number power supply impulses on the phase composition of the synthesized products was studied using X-ray diffractometry

The Cultural Politics of Proprietorship: The Socio-historical Evolution of Japanese Swordsmanship and its Correlation with Cultural Nationalism

This thesis provides a detailed socio-historical analysis of the evolutionary process of traditional Japanese swordsmanship (kenjutsu) from the inception of distinct martial schools (bugei-ryuha) in the fourteenth century, to its gradual progression into a modern competitive sport (kendo), and a subject of study in the current Japanese education system. The following questions with regards to the development of Japanese swordsmanship were analysed: 1) How did schools dedicated to the study of martial arts (bugei-ryuha) evolve, and why was the sword so important to the early traditions? 2) What was the process in which kenjutsu become “civilised”, and how did it relate to class identity in the Tokugawa period (1600-1868)? 3) In what way did kenjutsu transmute when class distinctions and national isolationist policies (sakoku) were abolished in the Meiji period (1868–1912)? 4) What were the cultural and political influences in the rise of “state” and “popular” nationalism, and how did they affect the “re-invention” and manipulation of kendo in the first half of the twentieth century? 5) How did post-war private and national cultural policy affect the reinstatement of kendo and its usefulness in inculcating a sense of “Japaneseness”? 6) What are the nationalistic motivations, and perceived dangers of the international propagation of kendo with regards to cultural propriotership? Through applying socio-historical concepts such as Norbert Elias’s “civilising process” and Eric Hobsbawm’s “invention of tradition”, as well as various descriptions of nationalism to the evolution of kendo, this thesis demonstrates how the martial art has continued to maintain a connection with the past, while simultaneously developing into a symbolic and discursive form of traditional culture representing a “cultural ethos” considered to be a manifestation of “Japaneseness”. Ultimately, kendo can be described as a kind of participatory based mind-body Nihonjinron. Japan’s current reaction as it ponders the repercussions if it were to somehow lose its status as the suzerain nation of kendo, i.e. as exclusive owners of kendo - a martial art perceived as one of the most representative forms of traditional Japanese culture – is also assessed in this thesis

Computerized Simulation of Interference in Thread Milling of Non-Symmetric Thread Profiles

Article fait en collaboration avec WZL, RWTH Aachen, Allemagne pendant mon CRCT.Thread milling is a machining technique which is becoming widely used in specific contexts such as large diameter threading. Furthermore, compared to tapping, it is fully adapted to produce internal threads in difficult-to-cut materials, because the tool can be easily removed if a breakage occurs. For thread milling, as well as for form milling, groove and worm machining, geometrical considerations are critical aspects to succeed surface machining with the required accuracy. Interference phenomena may appear and appropriate cutter profiles and tool trajectories have to be defined to generate the desired shape. The proposed study is focusing on the threading of non-symmetric profile. A geometrical model computing the envelope profiles and using full parametrical definitions of the tool and thread is proposed. Its exploitation allows an analysis to explain and to quantify the influencing parameters on overcut. Then, an iterative method based on a direct approach, is proposed to define the tool design allowing to machine non-symmetric threads with good accuracy

Kargılı adam

Abdullah Ziya'nın Çocuk Dünyası'nda tefrika edilen Kargılı Adam adlı romanıTelif hakları nedeniyle romanın tam metni verilememiştir

Demography and Population Projections of the Invasive Tunicate Styela clava in southern New Zealand

This thesis is about the demography of the tunicate Styela clava, a species of some notoriety because of its invasiveness and impacts in many parts of the world. Species assemblages have continuously changed throughout evolutionary history, but the rate of today’s anthropogenically facilitated dispersal is unparalleled in history. Non-indigenous species (NIS) are now considered one of the most important risks to native biodiversity. NIS become invasive by becoming both widespread and locally dominant. This requires that a species becomes established, spreads locally, and increases in abundance. In the early stages of invasion, its demography and life history characteristics are of crucial importance. In New Zealand, Styela has established populations in several places, but none of these populations has yet reached the high densities found in other countries. In Lyttelton Port, where this study was located, Styela was first noticed in 2005. It therefore presented an ideal situation to study an invasive species in its early stages of establishment and provided a potentially good model for understanding how invasive species get local traction and spread from initial infestation points. Therefore, I set out to determine demographic features of Styela to understand the numbers game of population dynamics. This study used empirical data on growth rates, size-frequencies through time, and size and age to maturity to test several models, including von Bertalanffy, Logistic dose-response, Ricker and power models of individual growth. The most useful proved to be the von Bertalanffy model. Styela individuals shrink frequently, so average growth rates were often quite low, even though some individuals reached 160 mm or more in total length. Mortality was greatest in summer, presumably after reproduction, and lowest in winter. Fewer than 5% of individuals survived 12 months, and most or all of these died soon afterwards. Populations were, therefore, essentially annual. Recruitment was difficult to determine because of the cryptic nature of small juveniles. However, size-frequency, abundance and mortality data indicated that recruitment most likely occurred in early spring (late-October), and then again in late summer, with growth to maturity (at c. 50 mm total length) within < 5 months. Several manipulative experiments showed that Styela did not readily capitalise on provision of free space but the other non-native ascidian, Ciona intestinalis, rapidly recruited. Transplants of Styela were greatly affected by C. intestinalis, which overgrew them, similar to a localised replacement of Styela by Ciona seen overseas. Lefkovitch modelling was used to test whether Styela had an “Achilles heel” in its life history, whereby managed removal could impact future populations. This showed that under several scenarios intervention would most likely be ineffectual. Overall, this study showed that the original populations in Lyttelton Port are either static or in decline, somewhat contrary to original expectations. Nevertheless, it appears that these small populations may be acting as stepping stones for spread of this species outside of the port

Ayarı bozuklar

Selahattin Enis'in Son Saat'te tefrika edilen Ayarı Bozuklar adlı roman

Predicting soil erosion with RUSLE in mediterranean agricultural systems at catchment scale

Accurate assessment of soil loss is essential for sustainable agricultural production, management and conservation planning, especially in productive rain-fed agro-ecosystems and protected areas. The European Union considers soil as a non-renewable resource and identifies that soil degradation has strong impacts on soil and water resources. In this work the Revised Universal Soil Loss Equation model was applied within a geographic information system in the Estaña catchment (Spanish Pre-Pyrenees) as representative of a Mediterranean agro-ecosystem to elaborate a map of soil erosion at high spatial resolution (5 x 5 m of cell size). The soil erodibility factor (K) is calculated from three different approaches to evaluate the importance of spatial variations in soil texture, field infiltration measurements (Kfs) and amount of coarse fragments. The average value of estimated soil loss for the whole study area is 2.3 Mg ha-1 yr-1 and the highest rates are estimated in crops in steep areas (5.8 Mg ha-1 yr-1) and trails (18.7 Mg ha-1 yr-1). Cultivated soils with high soil erosion rates (higher than 8 Mg ha-1 yr-1) represent 20% of the cultivated area. The average value of soil loss in areas with human disturbances (4.21 Mg ha-1 yr-1) is 4.4 times higher than that estimated for areas with natural vegetation (0.96 Mg ha-1 yr-1). Field validation with 137Cs shows that the estimated value of soil loss in barley fields with the K-Kfs-rocks factor improves the model predictions in comparison with those obtained with the K-texture and K-Kfs factors. The RUSLE model predicts a decrease in soil erosion in fields in accordance with the increase of the age of abandonment. Predicted values of soil erosion and measured soil organic matter and stoniness in old abandoned fields agree with those in areas of natural forest and indicate the recovery of the original conditions of the soil. Statistical analysis highlights that the C factor contributes most of the variability of the values of predicted soil erosion, the K and LS factors contribute in a similar way and the P factor contributes least to the variability of soil erosion. Cultivated soils developed over clay materials in high slope areas are the most susceptible to soil degradation processes in comparison with soils developed over limestones in gentle and medium slope areas. The recovery of terraces in steep fields and conservation of crop residues are proposed as soil conservation practices to reduce the magnitude of soil loss in the study area.This research was financially supported by the following project: “Soil erosion and carbon dynamic in Mediterranean agroecosystems: radioisotopic modelling at different spatial and temporal scales” (MEDEROCAR, CGL2008-00831/BTE) funded by the Spanish Ministry of Science and Innovation.Peer reviewe

On high-speed turning of a third-generation gamma titanium aluminide

Gamma titanium aluminides are heat-resistant intermetallic alloys predestined to be employed in components suffering from high mechanical stresses and thermal loads. These materials are regarded as difficult to cut, so this makes process adaptation essential in order to obtain high-quality and defect-free surfaces suitable for aerospace and automotive parts. In this paper, an innovative approach for longitudinal external high-speed turning of a third-generation Ti-45Al-8Nb- 0.2C-0.2B gamma titanium aluminide is presented. The experimental campaign has been executed with different process parameters, tool geometries and lubrication conditions. The results are discussed in terms of surface roughness/integrity, chip morphology, cutting forces and tool wear. Experimental evidence showed that, due to the high cutting speed, the high temperatures reached in the shear zone improve chip formation, so a crack-free surface can be obtained. Furthermore, the use of a cryogenic lubrication system has been identified in order to reduce the huge tool wear, which represents the main drawback when machining gamma titanium aluminides under the chosen process condition