165 research outputs found

    The Impacts of Species, Physiological Age and Spacing on Tree Form and Branching

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    This dissertation examined the impact of species, physiological age and spacing on tree form and branching at a Nelder experiment located near Rolleston, Canterbury. Two species were compared, Pinus radiata and Eucalyptus nitens, at a range of stockings from 271 stems/ha to 40,466 stems/ha. Within the P. radiata, two different physiological ages were compared. Stocking and species significantly affected (p-value <0.05) tree height, diameter at breast height (DBH), crown depth, branch mortality, branch angle, branch size and internode length. Only stocking was statistically significant for crown width, and height from the ground was also statistically significant for branch angle and branch mortality. DBH, crown width, crown depth, branch size and branch survival decreased with increasing stocking for both species. Branch angle and average internode length increased as stocking increased for both species, and branch angle and average internode length also increased as you moved away from the base of the tree. DBH, average internode length and branch size were significantly larger for P. radiata across all stockings, however branch mortality and branch angle were significantly larger for E. nitens. Physiological age was not statistically significant for any aspects of tree form or branching examined in this study

    Совершенствование процесса отбора и адаптации персонала отдела взыскания банка

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    Выпускная квалификационная работа содержит 114 страниц, 26 рисунков, 20 таблиц, 32 использованных источников, 1 приложение. Ключевые слова: персонал, банк, отбор, адаптация, отдел взыскания. Объектом исследования является отдел взыскания ООО Банк "А" Цель работа - разработать мероприятия направленные на совершенствование процесса отбора и адаптации персонала в отделе взыскания ООО Банк"А". В процессе исследования проводились исследования теоретических и методологических основ отбора и адаптации персонала в организации, был проведен анализ отбора и адаптации персонала отдела взыскания. В результате исследования, были разработаны мероприятия направленные на совершенствование процесса отбора и адаптации персонала отдела взыскания ООО Банк "А" Основные конструктивные, технологические и техникFinal qualifying work contains 114 pages, 26 ri-suncom, 20 tables, 32 used sources, 1 app. Keywords: staff, Bank, selection, adaptation, recovery Department of. The object of study is the recovery Department of the Bank "And". Purpose - to develop measures aimed at improving the process of selection and adaptation of personnel in the recovery Department of the Bank "And". In the process the research was carried out research of theoretical and methodological bases of selection and adaptation of personnel in the organization, an analysis was conducted of the se-lection and adaptation of personnel recovery. The study, activities were designed to improve the process of selection and adaptation of personnel recovery Department of the Bank "And". Level of implementation: the proposed activities adopted by the management of the Bank "And". Scope: any Russian Bank with the foreclosure Department. The significance of the work in the implementation of proposals to improve the process of selec-tion and adaptation of the staff is that it will allow you to select the most suitable candidates to work in the company, as well as accelerate the process of adaptation of the newcomer in a new place. In future we plan to implement the Bank developed activities aimed at improving the process of selection and adaptation of personnel recovery Department of the Ban

    The Atomic Layer Deposition Technique for the Fabrication of Memristive Devices: Impact of the Precursor on Pre-deposited Stack Materials

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    Atomic layer deposition (ALD) is a standard technique employed to grow thin-film oxides for a variety of applications. We describe the technique and demonstrate its use for obtaining memristive devices. The metal/insulator/metal stack is fabricated by means of ALD-grown HfO2, deposited on top of a highly doped Si substrate with an SiO2 film and a Ti electrode. Enhanced device capabilities (forming free, self-limiting current, non-crossing hysteretic current-voltage features) are presented and discussed. Careful analysis of the stack structure by means of X-ray reflectometry, atomic force microscopy, and secondary ion mass spectroscopy revealed a modification of the device stack from the intended sequence, HfO2/Ti/SiO2/Si. Analytical studies unravel an oxidation of the Ti layer which is addressed for the use of the ozone precursor in the HfO2 ALD process. A new deposition process and the model deduced from impedance measurements support our hypothesis: the role played by ozone on the previously deposited Ti layer is found to determine the overall features of the device. Besides, these ALD-tailored multifunctional devices exhibit rectification capability and long enough retention time to deserve their use as memory cells in a crossbar architecture and multibit approach, envisaging other potential applications

    Computational and experimental studies of diffusion in monoclinic HfO2

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    Research on hafnia and zirconia has received a boost in the last two decades, mainly because of their electrical properties. As materials with high dielectric permittivity and a wide band-gap, they can replace SiO2 in Si-based semiconductor devices as the gate dielectric, and they can be employed as the insulator in metal—insulator—metal structures, showing memristive behavior.[1,2] Anion, and possibly cation, transport is of fundamental importance for the annealing of such devices and the proposed mechanism of resistive switching (filament switching in the case of HfO2).[2,3] In this study, we investigated both cation and anion diffusion in HfO2 using diffusion experiments, with subsequent determination of the diffusion profiles by Secondary Ion Mass Spectrometry (SIMS). For the diffusion of oxygen in dense ceramics of monoclinic HfO2,, (18O/16O) isotope exchange anneals were performed in the temperature range 573 ≤ T / K ≤ 973 at an oxygen partial pressure of pO2 = 200 mbar.[4] All measured isotope profiles exhibited two features: the first feature, closer to the surface, was attributed to slow oxygen diffusion in an impurity silicate phase; the second feature, deeper in the sample, was attributed to oxygen diffusion in a homogeneous bulk phase. The activation enthalpy of oxygen tracer diffusion in bulk HfO2 was found to be ΔHD* ≈ 0.5 eV. In contrast to oxygen diffusion, diffusion of cations in HfO2 and other oxide-ion conductors is experimentally much more challenging. It is slow, requiring, therefore, high temperatures and long diffusion times. In the case of HfO2, there is also the problem of Si impurities (see above), which are hard to get rid of in ceramic samples. To alleviate these problems somewhat, we directly investigated the diffusion of Zr in thin films of nanocrystalline, monoclinic HfO2, prepared by Atomic Layer Deposition (ALD) and coupled with a sputtered top layer of ZrO2 as a diffusion source. Diffusion experiments were performed in the temperature range 1173 ≤ T / K ≤ 1323 in air. All measured diffusion profiles exhibited bulk diffusion and fast grain-boundary diffusion. Using numerical simulations, we were able to describe the profiles and extract diffusion coefficients for Zr diffusion in bulk HfO2 and along its grain boundaries. The activation enthalpies of diffusion in both cases were, surprisingly, the same at ΔHDb/Dgb ≈ 2.1 eV. They are also much lower than activation energies predicted by static atomistic simulations.[5] In order to aid the interpretation of the experimental data, we conducted atomistic simulations of cation diffusion in HfO2. Specifically we performed Molecular Dynamics (MD) simulations using the empirical pair potentials derived by Catlow and Lewis.[6,7] These potentials are suitable for describing defect behaviour in HfO2.[8,9] The activation enthalpy of Hf diffusion in bulk HfO2 we obtained from the MD simulations agrees exceedingly well with the experimental results: ΔHD* ≈ 2 eV. The reasons for this behaviour are discussed. [1]: V. A. Gritsenko et al., Phys. Rep 613, 1 (2016). [2]: R. Waser et al., Adv. Mater. 21, 2632 (2009). [3]: S. Uhlenbruck et al., Solid State Ionics 180, 418 (2009). [4]: M. P. Mueller, R. A. De Souza, Appl. Phys. Lett. 112, 051908 (2018). [5]: S. Beschnitt et al., J. Phys. Chem. C 119, 27307 (2015). [6]: C. R. A. Catlow, Proc. R. Soc. Lond. A. 353(1675), 533 (1977). [7]: G. Lewis, C. R. A. Catlow, J. Phys. C: Solid State Phys. 18(6), 1149 (1985). [8]: M. Schie et al., J. Chem. Phys. 146, 094508 (2017). [9]: M. Schie et al., Phys. Rev. Mat. 2, 035002 (2018

    Power supply for battery charging

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    В системах энергоснабжения космических аппаратов очень много внимания уделяется системам заряда аккумуляторных батарей. В состав данных систем входят фотоэлектрические преобразователи, преобразующие энергию солнца в электрический ток. Данные преобразователи имеют крайне низкие энергетические показатели. Предлагаемая работа направлена на повышение эффективности заряда аккумуляторных батарей, посредством применения резонансного инвертора.In the space power systems, much attention is paid to battery charging systems. The composition of these systems includes photoelectric converters that convert the energy of the sun into electric current. These converters have extremely low energy performance. The proposed paper is aimed at increasing the efficiency of batteries chargers, by applying a resonant inverter

    Defect-control of conventional and anomalous electron transport at complex oxide interfaces

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    Using low-temperature electrical measurements, the interrelation between electron transport, magnetic properties, and ionic defect structure in complex oxide interface systems is investigated, focusing on NdGaO3/SrTiO3 (100) interfaces. Field-dependent Hall characteristics (2–300 K) are obtained for samples grown at various growth pressures. In addition to multiple electron transport, interfacial magnetism is tracked exploiting the anomalous Hall effect (AHE). These two properties both contribute to a nonlinearity in the field dependence of the Hall resistance, with multiple carrier conduction evident below 30 K and AHE at temperatures ≲10  K. Considering these two sources of nonlinearity, we suggest a phenomenological model capturing the complex field dependence of the Hall characteristics in the low-temperature regime. Our model allows the extraction of the conventional transport parameters and a qualitative analysis of the magnetization. The electron mobility is found to decrease systematically with increasing growth pressure. This suggests dominant electron scattering by acceptor-type strontium vacancies incorporated during growth. The AHE scales with growth pressure. The most pronounced AHE is found at increased growth pressure and, thus, in the most defective, low-mobility samples, indicating a correlation between transport, magnetism, and cation defect concentratio

    El Ocaso de los dioses

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    De cada obra s'ha digitalitzat un programa sencer. De la resta s'han digitalitzat les parts que són diferents.Empresa: José F. ArquerOrquestra Simfònica del Gran Teatre del Liceu, director Laszlo HalaszPrograma de la temporada d'hivern 1956-1957 corresponent a la representació de El Ocaso de los Dioses, òpera d'un pròleg i tres actes amb música i llibret de Richard Wagne

    Boxnep - модульный подводный робот перспективных технологий

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    The article discusses the relevance of the underwater vehicles are able to solve a wide range of problems. The decision puts in a basis of the research is designing a modular underwater robot. It allows to make a mounting of various equipment and testing it in the water medium. The paper deals with the concept of the robot and its characteristics

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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