19 research outputs found

    Enhancing interferometric sensitivity by non-classical light from quantum non-demolition measurements in cavity QED

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    We propose an enhanced optical interferometer based on tailored non-classical light generated by nonlinear dynamics and projective measurements in a three-level atom cavity QED system. A coherent state in the cavity becomes dynamically entangled with two ground states of the atom and is transformed to a macroscopic superposition state via a projective measurement on the atom. We show that the resulting highly non-classical state can improve interferometric precision measurements well beyond the shot-noise limit once combined with a classical laser pulse at the input of a Mach-Zehnder interferometer. For a practical implementation, we identify an efficient phase shift estimation scheme based on the counting of photons at the interferometer output. Photon losses and photon-counting errors deteriorate the interferometer sensitivity, but we demonstrate that it still can be significantly better than the shot-noise limit under realistic conditions.Comment: 9 pages, 10 figure

    Soil Genesis PROPERTIES OF HUMUS HORIZONS OF SOILS DEVELOPED IN THE LOWER MONTANE BELT IN THE TATRA MOUNTAINS**

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    Abstract. The aim of the study is to evaluate differences occurring in the soil humus horizons between different types of forests. Soil samples were collected from spruce monoculture and natural beech sites within the lower montane zone in the Tatra Mountains. They were analyzed for organic carbon (OC), loss on ignition in ectohumus horizons, pH, fractional composition of organic matter and cellulose decomposition rate. The objects of investigation are two profiles representing Rendzic Leptosols under spruce and beech, one profile formed on cover bed, which can be classified as Haplic Leptosol under spruce forest and one Haplic Cambisol under the beech site. It is shown that different tree species strongly affect features of both ectohumus and endohumus horizons. This is visible in morphology of humus horizons as well as humus fraction composition which leads to acidification and to a descending cellulose decomposition rate. Another factor controlling features of humus horizons is parent material. It seems to be possible to separate effects which are results of vegetation and parent material features. This paper is a part of wider investigations continuing estimating the influence of spruce on the soil properties in the Tatra Mountains. A part of that investigation is to compare the humus horizons developed under spruce monoculture and natural beech forest. Many authors claim that coniferous trees affect the soil properties leading to their acidification The humification rate and humus features depend on the plant material. The chemical composition of a plant remnants leads to releasing different amounts of humus substances to the soil's environment. Needles of coniferous trees which P O L

    Dissolution of carbonate rock in soils under beech and spruce forests in the laboratory conditions

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    Chemical denudation plays a crucial role in affecting the water chemistry and the development of the relief, therefore the dissolution of carbonate rocks is the subject of numerous research. The aim of the study was to determine the effect of soil material derived from the organic (O) as well as humus (A) horizons of forest soils (common beech and Norway spruce stands) on the dissolution of rock. During one−year laboratory experiment standardized samples of dolomitic limestone placed in the soil material were washed with deionized water. The greatest loss of the sample rocks mass occurred in O material from Norway spruce stand (43.9‰ on average), while in other cases, the loss of rock samples mass was much lower and statistically non−significant. The total masses of calcium (Ca2+) leached from O material under beech and spruce stands were similar, however in the case of spruce most of Ca2+ derives from rock dissolution. Similarly, higher proportion of magnesium (Mg2+) leached from O material under Norway spruce derives from rock dissolution, although the total mass of Mg2+ leached is higher from O material under beech. The total mass of Ca2+ and Mg2+ leached from A material was similar or higher than from O material, however most of those ions derived from the soil material. The results indicate that the replacement of beech by Norway spruce can increase chemical denudation as well as Ca2+ and Mg2+ leaching, wherein Ca2+ leaching would be significantly greater than Mg2+
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