magnetic properties of metals and alloys

... Fermi-Dirac statistics and statistical moment method to study thermodynamic properties, magnetic properties of metals and metallic thin films" Purpose, object and scope of studying Apply of q-deformed ... thermodynamic properties and magnetic properties of the free electron gas in metal With all of the reasons described above, we apply the q-deformed algebraic theory to study heat capacity and paramagnetic ... Fermi-Dirac statistics to research heat capacity and paramagnetic susceptibility of free electron gas in metals at low temperatures, formula of heat capacity and magnetic susceptibility from the free electron...

Ngày tải lên: 01/11/2016, 20:14

... Electronic and magnetic properties of alkali and alkaline earth metals doped AlN: bulk to surfaces SANDHYA CHINTALAPATI (M.Sc; University of Hyderabad) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF ... units of bohr magneton 66 xiii List of Figures 1.1 Schematic... electronic and magnetic properties of magnetic semiconductors at the low-dimension Thus to identify the origin of ... the Mn3+ ion and spin down electron of O atom hop to another Mn3+ ion Therefore, charge hopping between Mn and. .. the electronic and magnetic properties of magnetic semiconductors...

Ngày tải lên: 09/09/2015, 08:12

... UNIVERSITY OF SCIENCE FACULTY OF PHYSICS Vu Thi Huong THE INFLUENCE OF COBALT ON CRYSTAL STRUCTURE AND MAGNETIC PROPERTIES OF NiMnSbB2 HEUSLER ALLOYS Submitted in partial fulfillment of the requirements ... dependence of magnetization under a magnetic field of 0.01 T (ZFC and FC) for the NiMnSbCo1B2 sample 38 Figure 3.6 The temperature dependence of entropy’s variation under magnetic fields of 0.3 ... magnetic fields of 0.3 T, 0.5T and 0.8T of NiMnSbB2 39 Figure 3.7 The temperature dependence of entropy’s variation under magnetic fields of 0.3 T, 0.5T and 0.8T of NiMnSbCo1B2 40 Thesis...

Ngày tải lên: 24/06/2016, 12:58

... technology, and information Metals and alloys are materials, which have been widely used by mankind for thousands of years, and this is no mere chance: metals have many remarkable properties One ... parameters of the matrix and of the hardening phase The subject of the last chapter is the peculiarities of the strain behavior of refractory metals A detailed review of all aspects of the problem ... Mechanism of Strain at High Temperatures Physical Model and Theory 43 Velocity of Dislocations 45 Dislocation Density 49 Rate of the Steady-State Creep 51 43 High Temperature Strain of Metals and Alloys, ...

Ngày tải lên: 10/08/2014, 12:21

... constants and external conditions The essence of this approach is defined as the physics of the processes, which are the structural background and the kinetic basis of the macroscopic deformation of metals ... solutions and superalloys Metals with face-centered and body-centered crystal lattices were examined: nickel, copper, iron, vanadium, niobium and molybdenum Nickel and iron are two of the most ... investigations of metals and alloys directly during high-temperature deformation The method of measurement of the irradiation intensities, which are diffracted by separate crystallites of the investigated...

Ngày tải lên: 10/08/2014, 12:21

... is of great importance for our understanding of the physical mechanism of high-temperature deformation Fig 3.16 Histograms of the distribution of distances between jogs in screw components of ... facecentered metals at temperatures of (0.40–0.70) Tm , and for body-centered ¯ metals at (0.45–0.65) Tm The values of D and η depend upon external pa¯ ¯ rameters, especially stress D decreases, and ... revealed as the result of systematic examination of the bright- and dark-field image pictures and diffraction patterns of a large number of specimens Most of the dislocations in specimens after hightemperature...

Ngày tải lên: 10/08/2014, 12:21

... measured during high-temperature strain of the metals and alloys under investigation The values of D are of the order of 0.7–2.0 µm, the values of η are of the order of 2.9–6.0 mrad The substructure ... adequate understanding of the phenomenon under consideration Now we can proceed to describe the physical mechanism of high-temperature deformation of pure metals and single-phase alloys Our aim ... three or four orders of magnitude at 850–1050K) 4.6 Formation of Jogs Fig 4.10 Comparison of the temperature dependence of the creep rates ε under stress of 80 MPa (a) and of the ˙ mean-square...

Ngày tải lên: 10/08/2014, 12:21

... that an adequate understanding of dislocation processes in these ranges of temperature and stress is of great practical importance. Most heat-resistant metals, steels and alloys operate at temperatures ... term on the right-hand side of Eq. (4.27). In Fig. 4.17 the calculated curves of the influence of temperature and stress on the Γ value are shown for two metals. The probability of dislocation emis- ... eval- uation of the strain rate was out of the question at that time, of course. As a matter of fact, the adjacent jogs of opposite signs slip along the dis- location line easily and would simply...

Ngày tải lên: 10/08/2014, 12:21

... submarines, nuclear reactors and landing apparatus The structure of the majority of nickel-based superalloys consists of a matrix i.e of the γ phase and particles of the hardening γ phase ... preliminary decreased value of λ and increased value of D lead to the strain rate decreasing when the applied stress is relatively low. [...]... Strain of Metals and Alloys, Valim Levitin ... lattice parameter of. .. oxidation and an acceptable density Such alloys – superalloys – have been developed The largest applications of superalloys are in aircraft and industrial gas...

Ngày tải lên: 10/08/2014, 12:21

... diagonal [10 ¯ 1] atoms of aluminum and nickel are altered. Atoms of Ni that are denoted as 1 and of Al that are denoted as 3 are located in the first slip plane. Atoms of Ni 2 and of Al 4 are located ... High-temperature Deformation of Superalloys 6.2 Changes in the Matrix of Alloys during Strain The specimens of industrial superalloys (see Table 2.1) were investigated in situ by means of the X-ray method ... results of measurements of the particle sizes and the data of the strain rate tests 99 100 6 High- temperature Deformation of Superalloys Finally, the minimum strain rate of a...

Ngày tải lên: 10/08/2014, 12:21

... strength of a superalloy. Methods of prediction of the properties of new superalloys are being devel- oped on the basis of integrated databases of superalloy composition and test results. The error of ... Comprehensive tests and investigations are needed in order to design new superalloys. Variation of the chemical composition of superalloys is known to be the main method for optimization of alloy properties, ... predict the properties of a new superalloy. This approach does not take into account the physical processes. The struc- ture of alloys, solution and precipitation of phases, the influence of elements...

Ngày tải lên: 10/08/2014, 12:21

... mechanism of strain of the investigated superalloys. There exists a competition between the Orowan mechanism of bowing of the dislocations between the γ  particles and the cutting of particles ... 7.4 On the Composition of Superalloys Some data about the influence of alloying elements on the strength of nickelbased superalloys...128 7 Single Crystals of Superalloys 1 293 K under shear ... Single Crystals of Superalloys 7.3 Deformation of Single-crystal Superalloys at Higher Temperatures and Lower Stress Increase in temperature up to 1223K results in a change in the shape of the curves....

Ngày tải lên: 10/08/2014, 12:21

... sub-boundaries and subgrains increases, and the structure eventually becomes cellular. 8.2 Alloys of Refractory Metals A review of the creep behavior of refractory metal alloys has been published [53]. ... behavior of the refractory metal alloys. The corresponding nominal compositions of alloys are presented in Table 8.3. Molybdenum-, niobium- and tantalum-based alloys have been de- veloped, studied and ... 0.3Hf. The microstructure of extruded and recrystallized material consists of a solid solution and of particles of titanium carbide, TiC. The particle sizes are between 200 and 500 nm. Creep curves...

Ngày tải lên: 10/08/2014, 12:21

... implementation of standards two and six of the National Service Framework for Older People in England (2001) 13 THE ASSESSMENT AND PREVENTION OF FALLS IN OLDER PEOPLE Aims of the guideline ✦ To evaluate and ... beneficial and adverse effects of the interventions; cost; acceptability to patients; level of evidence; quality of studies; size and precision of effect; and relevance and generalisability of included ... extracted: Author and country of origin; aim and objective; population and setting; number of participants; study design and method; outcome measurements and summary statistics; and comments on...

Ngày tải lên: 28/03/2014, 16:20

... effectiveness of various dissemination and implementation strategies aimed at changing practitioners' practice Grimshaw and colleagues' 2004 review of the effectiveness of guideline dissemination and implementation ... nature of the evidence-base, and how consensus was reached about the evidence and consideration of the benefits and harms Another set of questions also focused on the use of strategies such as passive ... the design of the survey, guided the analysis and helped draft the manuscript DS contributed to the interpretation of the results and drafting of the manuscript NB provided the data and contributed...

Ngày tải lên: 11/08/2014, 05:21

... effectiveness of various dissemination and implementation strategies aimed at changing practitioners' practice Grimshaw and colleagues' 2004 review of the effectiveness of guideline dissemination and implementation ... nature of the evidence-base, and how consensus was reached about the evidence and consideration of the benefits and harms Another set of questions also focused on the use of strategies such as passive ... the design of the survey, guided the analysis and helped draft the manuscript DS contributed to the interpretation of the results and drafting of the manuscript NB provided the data and contributed...

Ngày tải lên: 11/08/2014, 16:20

... implementation of the study Table 3a: Summary of the number of LREs in PTP3 group talks Table 3b: Summary of the number of LREs in PTP4 group talks Table 4a Summary of the number of turns in PTP3 ... number of pauses and the total pausing time, the mean length of run and the speech rate were also valuable features as a measure of fluency Yuan, F and R Ellis (2003) measured fluency in terms of ... point of view .17 2.1.2.3 From the pedagogical point of view 18 2.2 TASK- BASED PLANNING AND TASK PERFORMANCE 19 2.2.1 Definition of a task and a frame work of task-based...

Ngày tải lên: 07/09/2013, 13:02

... performed better and more accurately than those in NP group in terms of EFVF and EFNF (in terms of tense, subject verb agreement and pronouncing morpheme-s in plurality ) Conclusions and Suggestions ... Department at MSA - Nature of group work - Relationship between group work and individual presentation Objectives of the study  contribute more theory to the understandings of group discussion  ... Questionnaire Observation note The implementation of the study  Time : 10 weeks  Total number of participants: 16  Number of participants in a group:  Number of groups: ( No planning groups & Pre-planning...

Ngày tải lên: 29/01/2014, 10:33

... use of different types of questions to get different types of answers based on the level of students, and the level of difficulty of each task: -“Do you like swimming?” (to get short answer and ... is often mentioned as an approach that comprises two sets of theories: assumption of what to teach, and assumption of how to teach Assumption of what to teach In this assumption, Richards and ... classes 11B1 and 11B2 for the control groups, and other two classes 11B3 and 11B4 for experimental groups These classes were comparable in terms of total number of students, age and sex After...

Ngày tải lên: 05/02/2014, 22:02

... technologies and deliver it as a standalone application, outside of any browser Users need to install the AIR for Android run time on their Android devices, and then Flash-based Android apps run on top of ... ones you’ll use most often: ➤➤ Android Debug Bridge (tools/adb.exe) is used for installing AIR for Android apps and Android SDK to devices and the emulator ➤➤ Android SDK and AVD Manager (SDK ... to understand from the get-go the capabilities and limitations of the types of functionality you develop Device Support Support for Android and iOS APIs are similar, but at the time of writing,...

Ngày tải lên: 12/02/2014, 20:20