PRELIMINARY STUDY OF LOAD CARRIAGE ON PRIMARY SCHOOL CHILDREN IN MALAYSIA

The purpose of the study is to investigate the weight and content of school bags carried by primary school children in Malaysia. 175 school children (male and female) participated in the study. The subjects are divided into two groups, first year and second year groups. The weights of the children were noted with and without load. Results show that the first year group carries more than 25% of body weight (>25%BW) and the second year group carries >15% BW. The decreasing percentage of body weight is not caused by a decreasing amount of load but it occurs because of the increment of body weight

Electric readout of magnetization dynamics in a ferromagnet-semiconductor system

We apply an analysis of time-dependent spin-polarized current in a semiconductor channel at room temperature to establish how the magnetization configuration and dynamics of three ferromagnetic terminals, two of them biased and third connected to a capacitor, affect the currents and voltages. In a steady state, the voltage on the capacitor is related to spin accumulation in the channel. When the magnetization of one of the terminals is rotated, a transient current is triggered. This effect can be used for electrical detection of magnetization reversal dynamics of an electrode or for dynamical readout of the alignment of two magnetic contacts.Comment: Revised version, 8 pages, 3 figure

Spin-dependent properties of a two-dimensional electron gas with ferromagnetic gates

A theoretical prediction of the spin-dependent electron self-energy and in-plane transport of a two-dimensional electron gas in proximity with a ferromagnetic gate is presented. The application of the predicted spin-dependent properties is illustrated by the proposal of a device configuration with two neighboring ferromagnetic gates which produces a magnetoresistance effect on the channel current generated by nonmagnetic source and drain contacts. Specific results are shown for a silicon inversion layer with iron gates. The gate leakage current is found to be beneficial to the spin effects.Comment: 3 pages, 2 figures, Replaced with revised versio

Beyond the physical realm of mindfulness:the nature of reality and concept of mind in traditional eastern philosophy of Sufism and the quantum paradigm

Abstract. The pandemonium seizing the world is not so much a physical one, rather a reflection of the chaos in the human mind. As a result, a plethora of concepts have been proposed to address this need in society, one being mindfulness. Central to this concept of mindfulness is the nature of reality and notion of mind. Yet, contemporary mindfulness literature is sparse in addressing these fundamental aspects and instead tends to be undergirded by scientific evidence-based approach which is rooted in modern science also known as Classical Science. This trend is not only widespread in the contemporary mindfulness studies but is the sine qua non of the larger social sciences and humanities research traditions. Despite this prevalence, science has moved into a promising, contemporary branch of science of the Quantum where the non-physical, non-material reality is the default state. This new model of reality introduces a more holistic thought tradition of “both/and” probabilistic thinking perspective instead of “either/or”. Adopting this Quantum Science reality, this thesis explores the nature of reality and concept of mind in contemporary mindfulness and Sufism, comparing both frameworks to that of Quantum Science. Findings demonstrate parallel tenets with regards to the nature of reality, the nature of human and the concept of mind between Quantum Science and Sufism, ultimately bridging the gap between spirituality, religion and science. Furthermore, the thesis uncovers that the perpetual implicit assumptions underpinning contemporary mindfulness are still largely based on the axioms of Classical Science emphasizing physical matter. These axioms continue to assert influence in many academic disciplines even though it had been shown not to be a concrete, default view of science but resulting from historical circumstances. As such, contemporary mindfulness assumes that the mind is an epiphenomenon of the brain. Contrarily, both Sufism and Quantum Science demand a deeper and richer understanding of reality and matter that goes beyond the physical. Neither of them subscribes to the perspective that mind is an emergent property of the brain. Instead, the mind or consciousness, is metaphysical in essence. This significance given to the metaphysical inadvertently provides scientific legitimacy to philosophies, theories, methodologies, approaches and others that center around subjectivity like in education, better capturing the essence of the human

Spintronics for electrical measurement of light polarization

The helicity of a circularly polarized light beam may be determined by the spin direction of photo-excited electrons in a III-V semiconductor. We present a theoretical demonstration how the direction of the ensuing electron spin polarization may be determined by electrical means of two ferromagnet/semiconductor Schottky barriers. The proposed scheme allows for time-resolved detection of spin accumulation in small structures and may have a device application.Comment: Revised version, 8 two-column pages, 5 figures; Added: a comprehensive time dependent analysis, figures 3b-3c & 5, equations 6 & 13-16 and 3 references. submitted to Phys. Rev.

High multipole transitions in NIXS: valence and hybridization in 4f systems

Momentum-transfer (q) dependent non-resonant inelastic x-ray scattering measurements were made at the N4,5 edges for several rare earth compounds. With increasing q, giant dipole resonances diminish, to be replaced by strong multiplet lines at lower energy transfer. These multiplets result from two different orders of multipole scattering and are distinct for systems with simple 4f^0 and 4f^1 initial states. A many-body theoretical treatment of the multiplets agrees well with the experimental data on ionic La and Ce phosphate reference compounds. Comparing measurements on CeO2 and CeRh3 to the theory and the phosphates indicates sensitivity to hybridization as observed by a broadening of 4f^0-related multiplet features. We expect such strong, nondipole features to be generic for NIXS from f-electron systems

Spin accumulation in forward-biased MnAs/GaAs Schottky diodes

We describe a new means for electrically creating spin polarization in semiconductors. In contrast to spin injection of electrons by tunneling through a reverse-biased Schottky barrier, we observe spin accumulation at the metal/semiconductor interface of forward-biased ferromagnetic Schottky diodes, which is consistent with a theory of spin-dependent reflection off the interface. Spatiotemporal Kerr microscopy is used to image the electron spin and the resulting dynamic nuclear polarization that arises from the non equilibrium carrier polarization.Comment: 13 pages, 4 figures, submitted for publicatio

Eigenvalue spectrum for single particle in a spheroidal cavity: A Semiclassical approach

Following the semiclassical formalism of Strutinsky et al., we have obtained the complete eigenvalue spectrum for a particle enclosed in an infinitely high spheroidal cavity. Our spheroidal trace formula also reproduces the results of a spherical billiard in the limit $\eta\to1.0$. Inclusion of repetition of each family of the orbits with reference to the largest one significantly improves the eigenvalues of sphere and an exact comparison with the quantum mechanical results is observed upto the second decimal place for $kR_{0}\geq{7}$. The contributions of the equatorial, the planar (in the axis of symmetry plane) and the non-planar(3-Dimensional) orbits are obtained from the same trace formula by using the appropriate conditions. The resulting eigenvalues compare very well with the quantum mechanical eigenvalues at normal deformation. It is interesting that the partial sum of equatorial orbits leads to eigenvalues with maximum angular momentum projection, while the summing of planar orbits leads to eigenvalues with $L_z=0$ except for L=1. The remaining quantum mechanical eigenvalues are observed to arise from the 3-dimensional(3D) orbits. Very few spurious eigenvalues arise in these partial sums. This result establishes the important role of 3D orbits even at normal deformations.Comment: 17 pages, 7 ps figure

Linking entanglement and quantum phase transitions via density functional theory

Density functional theory (DFT) is shown to provide a novel conceptual and computational framework for entanglement in interacting many-body quantum systems. DFT can, in particular, shed light on the intriguing relationship between quantum phase transitions and entanglement. We use DFT concepts to express entanglement measures in terms of the first or second derivative of the ground state energy. We illustrate the versatility of the DFT approach via a variety of analytically solvable models. As a further application we discuss entanglement and quantum phase transitions in the case of mean field approximations for realistic models of many-body systems.Comment: 6 pages, 2 figure

Optically-controlled single-qubit rotations in self-assembled InAs quantum dots

We present a theory of the optical control of the spin of an electron in an InAs quantum dot. We show how two Raman-detuned laser pulses can be used to obtain arbitrary single-qubit rotations via the excitation of an intermediate trion state. Our theory takes into account a finite in-plane hole $g$-factor and hole-mixing. We show that such rotations can be performed to high fidelities with pulses lasting a few tens of picoseconds.Comment: 6 pages, 4 figures; minor changes, J-ref adde