Theoretical Description of Pulsed RYDMR: Refocusing Zero-Quantum and Single Quantum Coherences

A theoretical description of pulsed reaction yield detected magnetic resonance (RYDMR) is proposed. In RYDMR, magnetic resonance spectra of radical pairs (RPs) are indirectly detected by monitoring their recombination yield. Such a detection method is significantly more sensitive than conventional electron paramagnetic resonance (EPR), but design of appropriate pulse sequences for RYDMR requires additional effort because of a different observable. In this work various schemes for generating spin-echo like signals and detecting them by RYDMR are treated. Specifically, we consider refocusing of zero-quantum coherences (ZQCs) and single-quantum coherences (SQCs) by selective as well as by non-selective pulses and formulate a general analytical approach to pulsed RYDMR, which makes an efficient use of the product operator formalism. We anticipate that these results are of importance for RYDMR studies of elusive paramagnetic particles, notably, in organic semiconductors

Study of distance learning opportunities in inclusive education system

© Medwell Journals, 2015. Relevance of the study of distance learning is based on the need to provide an available education for all social groups to exercise the rights of people with special educational needs as well as for children with disabilities. Since distance learning is one of the alternatives for a comprehensive and high-quality education for people with disabilities, it becomes of particular relevance and value in the system of inclusive education. Objective of this study is to promote distance learning technologies that address the main problem of children with disabilities lying in the lack of communication with other people, especially their peers. Distance learning technologies create the real possibility of intercommunication between children during the disciplinary and thematic collective activities both vertically (teacher pupil) and horizontally (between pupils), via e-mail, conferences, chat, virtual seminars, etc. The leading fields of distance learning were open-ended free pace of work; studying the place comfortable for student, i.e., home-like environment; modularity of educational process where each section of the content of educational material creates a holistic view of a specific field of knowledge; person-centered learning approach and the use of different methods, forms and means of cooperation in the independent but controlled learning of knowledge and skills. Developing a model of inclusive education based on distance learning will allow students to achieve the following results: to get an education in accordance with their individual educational needs, aptitudes and abilities; allay their fear of human differences and strengthen calm and understanding of reality and create tolerance in accepting both ordinary people and people with disabilities, etc. Materials of this study may be useful in both organization of inclusive education and general education system as a whole

Analysis of Nutation Patterns in Fourier-Transform NMR of Non-Thermally Polarized Multispin Systems

The complex spin order of hyperpolarized multispin systems giving rise to anomalous NMR spectral patterns that vary with the RF excitation angle is analyzed by decomposing its nutation behavior in a superposition of Fourier harmonics. The product operator formalism is applied to calculating the spectral contributions of the various mutual alignments of scalar coupled spins. Two cases are treated, namely systems exhibiting only differences in population of their spin states and systems showing in addition zero-quantum coherences between states, a situation often seen at hyperpolarization. After deriving the general solution a number of representative examples are discussed in detail. The theoretical treatment is applied to analyzing the spin order observed in a hyperpolarized two-spin system that is prepared in the singlet state by para-hydrogen induced polarization

Study of distance learning opportunities in inclusive education system

© Medwell Journals, 2015. Relevance of the study of distance learning is based on the need to provide an available education for all social groups to exercise the rights of people with special educational needs as well as for children with disabilities. Since distance learning is one of the alternatives for a comprehensive and high-quality education for people with disabilities, it becomes of particular relevance and value in the system of inclusive education. Objective of this study is to promote distance learning technologies that address the main problem of children with disabilities lying in the lack of communication with other people, especially their peers. Distance learning technologies create the real possibility of intercommunication between children during the disciplinary and thematic collective activities both vertically (teacher pupil) and horizontally (between pupils), via e-mail, conferences, chat, virtual seminars, etc. The leading fields of distance learning were open-ended free pace of work; studying the place comfortable for student, i.e., home-like environment; modularity of educational process where each section of the content of educational material creates a holistic view of a specific field of knowledge; person-centered learning approach and the use of different methods, forms and means of cooperation in the independent but controlled learning of knowledge and skills. Developing a model of inclusive education based on distance learning will allow students to achieve the following results: to get an education in accordance with their individual educational needs, aptitudes and abilities; allay their fear of human differences and strengthen calm and understanding of reality and create tolerance in accepting both ordinary people and people with disabilities, etc. Materials of this study may be useful in both organization of inclusive education and general education system as a whole

Study of distance learning opportunities in inclusive education system

© Medwell Journals, 2015. Relevance of the study of distance learning is based on the need to provide an available education for all social groups to exercise the rights of people with special educational needs as well as for children with disabilities. Since distance learning is one of the alternatives for a comprehensive and high-quality education for people with disabilities, it becomes of particular relevance and value in the system of inclusive education. Objective of this study is to promote distance learning technologies that address the main problem of children with disabilities lying in the lack of communication with other people, especially their peers. Distance learning technologies create the real possibility of intercommunication between children during the disciplinary and thematic collective activities both vertically (teacher pupil) and horizontally (between pupils), via e-mail, conferences, chat, virtual seminars, etc. The leading fields of distance learning were open-ended free pace of work; studying the place comfortable for student, i.e., home-like environment; modularity of educational process where each section of the content of educational material creates a holistic view of a specific field of knowledge; person-centered learning approach and the use of different methods, forms and means of cooperation in the independent but controlled learning of knowledge and skills. Developing a model of inclusive education based on distance learning will allow students to achieve the following results: to get an education in accordance with their individual educational needs, aptitudes and abilities; allay their fear of human differences and strengthen calm and understanding of reality and create tolerance in accepting both ordinary people and people with disabilities, etc. Materials of this study may be useful in both organization of inclusive education and general education system as a whole

Study of distance learning opportunities in inclusive education system

© Medwell Journals, 2015. Relevance of the study of distance learning is based on the need to provide an available education for all social groups to exercise the rights of people with special educational needs as well as for children with disabilities. Since distance learning is one of the alternatives for a comprehensive and high-quality education for people with disabilities, it becomes of particular relevance and value in the system of inclusive education. Objective of this study is to promote distance learning technologies that address the main problem of children with disabilities lying in the lack of communication with other people, especially their peers. Distance learning technologies create the real possibility of intercommunication between children during the disciplinary and thematic collective activities both vertically (teacher pupil) and horizontally (between pupils), via e-mail, conferences, chat, virtual seminars, etc. The leading fields of distance learning were open-ended free pace of work; studying the place comfortable for student, i.e., home-like environment; modularity of educational process where each section of the content of educational material creates a holistic view of a specific field of knowledge; person-centered learning approach and the use of different methods, forms and means of cooperation in the independent but controlled learning of knowledge and skills. Developing a model of inclusive education based on distance learning will allow students to achieve the following results: to get an education in accordance with their individual educational needs, aptitudes and abilities; allay their fear of human differences and strengthen calm and understanding of reality and create tolerance in accepting both ordinary people and people with disabilities, etc. Materials of this study may be useful in both organization of inclusive education and general education system as a whole

Theory of pulsed reaction yield detected magnetic resonance

We propose pulse sequences for Reaction Yield Detected Magnetic Resonance (RYDMR), which are based on refocusing the zero-quantum coherences in radical pairs by non-selective microwave pulses and using the population of a radical pair singlet spin state as an observable. The new experiments are analogues of existing EPR experiments such as the primary echo, Carr–Purcell, ESEEM, stimulated echo and Mims ENDOR. All pulse sequences are supported by analytical results and numerical calculations. The pulse sequences can be used for more efficient and highly detailed characterization of intermediates of chemical reactions and charge carriers in organic semiconductors

exploiting the advantages of coherent electron spin motion

A theoretical approach is proposed to describe Overhauser-type Dynamic Nuclear Polarization (DNP) for pulsed EPR pumping by application of a train of short pulses with a duration on the nanosecond time scale. We obtained an elegant general expression for the NMR enhancement provided by the DNP effect. The expression for the enhancement is similar to that known for cw-pumping except for the saturation factor, which is re-defined as the deviation of the electron spin magnetization from its equilibrium value averaged over the cycle of the pulse sequence. It is shown that one can achieve the maximal theoretically allowed NMR enhancement for pulsed pumping even when the duty cycle of pumping is low. This becomes possible because coherent motion of the electron spins in the B1-field is exploited, a key feature of the pulsed DNP experiment also enabling optimization of the achievable NMR enhancement. The dependence of the effect on the duty cycle, pulse duration and electron spin relaxation times has been studied in detail. Once the lines in the EPR spectrum are inhomogeneously broadened, higher DNP effects are expected in the pulsed pumping mode than in the cw-mode for the same total power of microwave irradiation. The theoretical results are in good agreement with experimental data obtained for the pumping frequencies of 300 MHz and 1.4 GHz