52 research outputs found

    Quality of a Which-Way Detector

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    We introduce a measure Q of the "quality" of a quantum which-way detector, which characterizes its intrinsic ability to extract which-way information in an asymmetric two-way interferometer. The "quality" Q allows one to separate the contribution to the distinguishability of the ways arising from the quantum properties of the detector from the contribution stemming from a-priori which-way knowledge available to the experimenter, which can be quantified by a predictability parameter P. We provide an inequality relating these two sources of which-way information to the value of the fringe visibility displayed by the interferometer. We show that this inequality is an expression of duality, allowing one to trace the loss of coherence to the two reservoirs of which-way information represented by Q and P. Finally, we illustrate the formalism with the use of a quantum logic gate: the Symmetric Quanton-Detecton System (SQDS). The SQDS can be regarded as two qubits trying to acquire which way information about each other. The SQDS will provide an illustrating example of the reciprocal effects induced by duality between system and which-way detector.Comment: 10 pages, 5 figure

    Isolation and Screening of Diesel Degrading Bacteria From Ship Dismantling Facility at Tanjungjati, Madura, Indonesia

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    The ship dismantling industry is a cause of contamination of the environment by diesel. The objectives of this study were to isolate and screen diesel degrading bacteria from diesel contaminated areas. Diesel contaminated seawater and soil samples were collected from a ship dismantling facility at Tanjungjati, Madura, Indonesia. Isolation was conducted with an aseptic technique and growing the mixture culture was carried out based on the pour plate method. After 24 h of incubation, thirteen bacteria strains were isolated from diesel contaminated seawater and soil samples from the area of study. The isolated bacteria were identified based on morphological characterization. Mostly gram positive bacteria were found. The isolated bacteria were screened by using nutrient agar medium containing various diesel concentrations (0%, 5%, 10%, and 15% (v/v)). The result of the screening test showed that the bacteria coded EL and CT displayed the best resistance and highest growth in diesel polluted medium. It was shown that both of them potentially have a higher capability of utilizing diesel as carbon and energy source than the others

    Curve crossing in linear potential grids: the quasidegeneracy approximation

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    The quasidegeneracy approximation [V. A. Yurovsky, A. Ben-Reuven, P. S. Julienne, and Y. B. Band, J. Phys. B {\bf 32}, 1845 (1999)] is used here to evaluate transition amplitudes for the problem of curve crossing in linear potential grids involving two sets of parallel potentials. The approximation describes phenomena, such as counterintuitive transitions and saturation (incomplete population transfer), not predictable by the assumption of independent crossings. Also, a new kind of oscillations due to quantum interference (different from the well-known St\"uckelberg oscillations) is disclosed, and its nature discussed. The approximation can find applications in many fields of physics, where multistate curve crossing problems occur.Comment: LaTeX, 8 pages, 8 PostScript figures, uses REVTeX and psfig, submitted to Physical Review

    Ontogenic development of the mouth and digestive tract in larval Malaysian mahseer, Tor tambroides Bleeker.

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    This study analysed morphology and histology of the developing mouth and digestive tract of the Malaysian mahseer larvae to assess the best weaning time to a compound diet for the fry on the basis of their morphological features. The mouth development was monitored using light and scanning electron microscopy; the development of the alimentary canal was followed histologically using light microscopy after haematoxylin-eosin staining. The larval mouth opened 1day after hatching (1 DAH); the histological structures of oesophagus were completed by 5 DAH. At 2 DAH, differentiation of enterocytes began, and at 7 DAH the supranuclear protein inclusion appeared in the posterior intestine. The hepatopancreas was structurally completed at 4-5 DAH, coinciding with the start of exogenous feeding and the evidence of lipid storage in the liver. It was concluded that Malaysian mahseer larvae should certainly be able to ingest, and possibly digest and absorb, a formulated diet of 287μm Ø from 7 DAH onward

    The Uncertainty Relation in "Which-Way" Experiments: How to Observe Directly the Momentum Transfer using Weak Values

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    A which-way measurement destroys the twin-slit interference pattern. Bohr argued that distinguishing between two slits a distance s apart gives the particle a random momentum transfer \wp of order h/s. This was accepted for more than 60 years, until Scully, Englert and Walther (SEW) proposed a which-way scheme that, they claimed, entailed no momentum transfer. Storey, Tan, Collett and Walls (STCW) in turn proved a theorem that, they claimed, showed that Bohr was right. This work reviews and extends a recent proposal [Wiseman, Phys. Lett. A 311, 285 (2003)] to resolve the issue using a weak-valued probability distribution for momentum transfer, P_wv(\wp). We show that P_wv(\wp) must be wider than h/6s. However, its moments can still be zero because P_wv(\wp) is not necessarily positive definite. Nevertheless, it is measurable in a way understandable to a classical physicist. We introduce a new measure of spread for P_wv(\wp): half of the unit-confidence interval, and conjecture that it is never less than h/4s. For an idealized example with infinitely narrow slits, the moments of P_wv(\wp) and of the momentum distributions are undefined unless a process of apodization is used. We show that by considering successively smoother initial wave functions, successively more moments of both P_wv(\wp) and the momentum distributions become defined. For this example the moments of P_wv(\wp) are zero, and these are equal to the changes in the moments of the momentum distribution. We prove that this relation holds for schemes in which the moments of P_wv(\wp) are non-zero, but only for the first two moments. We also compare these moments to those of two other momentum-transfer distributions and \hat{p}_f-\hat{p}_i. We find agreement between all of these, but again only for the first two moments.Comment: 14 pages, 6 figures, submitted to J. Opt.

    Fast noise in the Landau-Zener theory

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    We study the influence of a fast noise on Landau-Zener transitions. We demonstrate that a fast colored noise much weaker than the conventional white noise can produce transitions itself or can change substantially the Landau-Zener transition probabilities. In the limit of fast colored or strong white noise we derive asymptotically exact formulae for transition probabilities and study the time evolution of a spin coupled to the noise and a sweeping magnetic field.Comment: 28 pages, 5 figure

    Achieving Education for Sustainable Development (ESD) in Early Childhood Education Through Critical Reflection in Transformative Learning

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    The central role of education in creating a more sustainable future has been already recognized by educators and policy-makers alike. This chapter argues that this can only be truly achieved through the efforts of teachers in implementing an “education of a different kind,” a general educational shift that seeks to encompass a converging transformation of the priorities and mindsets of education professionals. In this regard, the professional preparation of teachers, as the leading actors in shaping children’s learning processes, and their continuous professional development are vital considerations for Education for Sustainable Development (ESD) to be successfully achieved. Linking transformative learning and ESD has emerged as a distinct and useful pedagogy because they both support the process of critically examining habits of mind, then revising these habits and acting upon the revised point of view. This study aims to describe and evaluate the potential of transformative learning in innovating mainstream education toward sustainability by focusing on the role of critical reflection in a capacity building research project realized in Turkey. The data was gathered from 24 early childhood educators using a mixed-method research design involving learning diaries, a learning activities survey, and follow-up interviews. This chapter identified content, context, and application method of the in-service training as factors that have contributed to the reflective practices of the participants. In addition, presenting the implications regarding the individual differences in how learners engage in critical reflection practices, this research offers a framework for a content- and process-based approach derived from Mezirow’s conception of critical reflection
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