49 research outputs found
Controllability and universal three-qubit quantum computation with trapped electron states
We show how to control and perform universal three-qubit quantum computation
with trapped electron quantum states. The three qubits are the electron spin,
and the first two quantum states of the cyclotron and axial harmonic
oscillators. We explicitly show how the universal gates can be performed. As an
example of a non-trivial quantum algorithm, we outline the implementation of
the Deutsch-Jozsa algorithm in this system.Comment: 4 pages, 1 figure. Typos corrected. The original publication is
available at http://www.springerlink.co
PHYSICAL AND CHEMICAL CHARASTERISTIC OF URBAN AEROSOL OF CENTRAL BALKANS (BELGRADE)
Size-segregated urban aerosol of Belgrade center (44049'14''N, 20027'44''E) was studied during the summer-autumn 2008. The representative location in traffic area Studentski trg was chosen for investigating physical and chemical characteristics of collected particles. Particle size distribution in the size range Dp £ 0.49 µm, 0.49 £ Dp £ 0.95 µm, 0.95 £ Dp £ 1.5 µm, 1.5 £ Dp £ 3.0 µm, 3.0 £ Dp £ 7.2 µm and Dp ³ 7.2 µm were measured. Aerosol samples were submitted to gravimetric SEM analysis. The shape, size and chemical composition of the fine and coarse particles were analyzed. The imaging was carried out by SEM (Nova NanoSEM 230, FEI, USA). The same SEM was also used for the EDX measurements performed. The particles collected on fiber filters for SEM imaging were further on coated with 4 nm Pt layer to improve conductivity of the samples. The morphological and chemical composition suggested that the most abundant particles were carbonaceous soot but also microbes and natural and anthropogenic inorganic mineral materials. The chemical characterization was performed on a semi-quantitative level. The contents of the carbon were up to 70% or higher. In the samples were dominating next others elements: O, Mo, Si, Fe, Ca, Al, K, Mg
Size-segregated concentration of heavy metals in an urban aerosol of the Balkans region (Belgrade)
This work focuses on the heavy metals contents of the size-segregated urban aerosol of the
continental area of Balkans. The distribution of nano/micron heavy metals in the size-segregated urban
aerosol of Belgrade center was studied during the summer–autumn of 2008. The particle size distribution in
the size ranges Dp ≤ 0.49 μm, 0.49 ≤ Dp ≤ 0.95 μm, 0.95 ≤ Dp ≤ 1.5 μm, 1.5 ≤ Dp ≤ 3.0 μm, 3.0 ≤ Dp ≤ 7.2 μm
and Dp ≥ 7.2 μm was measured. The aerosol samples were submitted to gravimetric and chemical analyses.
The obtained mean mass concentration of the PM fractions was in accordance with an urban aerosol
distribution. The aerosol mass concentrations were determined by gravimetric measurements (mGM) and, for
heavy metals analyzed by ICP/MS
Size distributed aerosol mass concentration and chemical composition in Belgrade during summer-autumn 2008
Physical and chemical characterizations of the atmospheric aerosol were carried out in urban area of Belgrade. This work focuses on the size-segregated aerosol chemical composition observed during the summer-autumn 2008th. Aerosol samples were submitted to gravimetric and chemical analyses. Mean random uncertainties associated with determination of Na+
, NH4 +, K+, Mg2+, Ca2+, Cl-, NO3- and SO42- were assessed
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Results of the MAJORANA DEMONSTRATOR's Search for Double-Beta Decay of 76Ge to Excited States of 76Se
The MAJORANA DEMONSTRATOR is searching for double-beta decay of 76Ge to excited states (E.S.) in 76Se using a modular array of high purity Germanium detectors. 76Ge can decay into three E.S.s of 76Se. The E.S. decays have a clear event signature consisting of a ββ-decay with the prompt emission of one or two γ-rays, resulting in with high probability in a multi-site event. The granularity of the DEMONSTRATOR detector array enables powerful discrimination of this event signature from backgrounds. Using 21.3 kg-y of isotopic exposure, the DEMONSTRATOR has set world leading limits for each E.S. decay, with 90% CL lower half-life limits in the range of (0.56 2.1) ⋅ 1024 y. In particular, for the 2v transition to the first 0+ E.S. of 76Se, a lower half-life limit of 0.68 ⋅ 1024 at 90% CL was achieved
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ADC Nonlinearity Correction for the Majorana Demonstrator
Imperfections in analog-to-digital conversion (ADC) cannot be ignored when signal digitization requirements demand both wide dynamic range and high resolution, as is the case for the Majorana Demonstrator 76Ge neutrinoless double-beta decay search. Enabling the experiment's high-resolution spectral analysis and efficient pulse shape discrimination required careful measurement and correction of ADC nonlinearities. A simple measurement protocol was developed that did not require sophisticated equipment or lengthy data-taking campaigns. A slope-dependent hysteresis was observed and characterized. A correction applied to digitized waveforms prior to signal processing reduced the differential and integral nonlinearities by an order of magnitude, eliminating these as dominant contributions to the systematic energy uncertainty at the double-beta decay Q value
¿“Nos enfrentamos y nos abrazamos”? Un nuevo recorrido por los usos oficiales del pasado durante el bicentenario de la Revolución de Mayo
El presente trabajo analiza, en primer lugar, los modos en que la historia argentina se tradujo, durante los festejos oficiales del bicentenario de la Revolución de Mayo, en artefactos culturales y festivos dirigidos a atraer un público vasto, prestando especial atención a los usos del pasado allí exhibidos. En segundo lugar, pone en relación dichas operaciones con las variaciones ocurridas en el nivel de las prácticas políticas gubernamentales tras la crisis política de 2008. En última instancia, se plantea que el gobierno de Cristina Fernández de Kirchner se inclinó, al momento de proyectar el festejo patrio en cuestión, por una lógica discursiva liberal–centrada, especialmente, en el consenso inclusivo y la aceptación de las diferencias–con el fin de matizar la partición del espacio socio-político, exhibir una nación reconciliada, interpelar a la sociedad argentina en su conjunto y, de ese modo, contribuir a la reconstrucción de su hegemonía política.Firstly, this paper analyzes how Argentinian history was translated, during the national celebrations of the May Revolution bicentennial, into cultural and festive devices aimed at attracting a massive audience, paying special attention to the uses of the past displayed. Secondly, it illustrates the relations between these operations and the variations of government policy that occurred after the 2008 political crisis. Ultimately, it claims that the Cristina Fernández de Kirchner administration adopted, when it came to planning this national holiday, a liberal discursive logic – mainly characterized by inclusive consensus and pluralism – in order to ease the division of the social and political space, display a reconciled nation, address the entire Argentinean society and, thereby, contribute to the reconstruction of Kirchnerist hegemony.Fil: Amorebieta y Vera, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones en Humanidades y Ciencias Sociales. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales; Argentin
Mass distributions and morphological and chemical characterization of urban aerosols in the continental Balkan area (Belgrade)
This work presents characteristics of atmospheric aerosols of urban central Balkans area, using a size-segregated aerosol sampling method, calculation of mass distributions, SEM/EDX characterization, and ICP/MS analysis. Three types of mass distributions were observed: distribution with a pronounced domination of coarse mode, bimodal distribution, and distribution with minimum at 1 μm describing the urban aerosol. SEM/EDX analyses have shown morphological difference and variation in the content of elements in samples. EDX spectra demonstrate that particles generally contain the following elements: Al, Ca, K, Fe, Mg, Ni, K, Si, S. Additionally, the presence of As, Br, Sn, and Zn found in air masses from southeast segment points out the anthropogenic activities most probably from mining activities in southeastern part of Serbia. The ratio Al/Si equivalent to the ratio of desert dust was associated with air masses coming from southeastern and southwestern segments, pointing to influences from North Africa and Middle East desert areas whereas the Al/Si ratio in other samples is significantly lower. In several samples, we found high values of aluminum in the nucleation mode. Samples with low share of crustal elements in the coarse mode are collected when Mediterranean air masses prevailed, while high share in the coarse mode was associated with continental air masses that could be one of the approaches for identification of the aerosol origin. Graphical abstract ᅟ.This work presents characteristics of atmospheric aerosols of urban central Balkans area, using a size-segregated aerosol sampling method, calculation of mass distributions, SEM/EDX characterization, and ICP/MS analysis. Three types of mass distributions were observed: distribution with a pronounced domination of coarse mode, bimodal distribution, and distribution with minimum at 1 mu m describing the urban aerosol. SEM/EDX analyses have shown morphological difference and variation in the content of elements in samples. EDX spectra demonstrate that particles generally contain the following elements: Al, Ca, K, Fe, Mg, Ni, K, Si, S. Additionally, the presence of As, Br, Sn, and Zn found in air masses from southeast segment points out the anthropogenic activities most probably from mining activities in southeastern part of Serbia. The ratio Al/Si equivalent to the ratio of desert dust was associated with air masses coming from southeastern and southwestern segments, pointing to influences from North Africa and Middle East desert areas whereas the Al/Si ratio in other samples is significantly lower. In several samples, we found high values of aluminum in the nucleation mode. Samples with low share of crustal elements in the coarse mode are collected when Mediterranean air masses prevailed, while high share in the coarse mode was associated with continental air masses that could be one of the approaches for identification of the aerosol origin
Trace elements in size-segregated urban aerosol in relation to the anthropogenic emission sources and the resuspension
Size segregated particulate samples of atmospheric aerosols in urban site of continental part of Balkans were collected during 6 months in 2008. Six stages impactor in the size ranges: Dp ≤ 0.49 μm, 0.49 < Dp ≤ 0.95 μm, 0.95 < Dp ≤ 1.5 μm, 1.5 < Dp ≤ 3.0 μm, 3.0 < Dp ≤ 7.2 μm, and 7.2 < Dp ≤ 10.0 μm was applied for sampling. ICP-MS was used to quantify elements: Al, As, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Na, Ni, Mg, Mn, Pb, Sb, V, and Zn. Two main groups of elements were investigated: (1) K, V, Ni, Zn, Pb, As, and Cd with high domination in nuclei mode indicating the combustion processes as a dominant sources and (2) Al, Fe, Ca, Mg, Na, Cr, Ga, Co, and Li in coarse mode indicating mechanical processes as their main origin. The strictly crustal origin is for Mg, Fe, Ca, and Co while for As, Cd, K, V, Ni, Cu, Pb, and Zn dominates the anthropogenic influence. The PCA analysis has shown that main contribution is of resuspension (PC1, σ2 ≈ 30 %) followed by traffic (PC2, σ2 ≈ 20 %) that are together contributing around 50 % of elements in the investigated urban aerosol. The EF model shows that major origin of Cd, K, V, Ni, Cu, Pb, Zn, and As in the fine mode is from the anthropogenic sources while increase of their contents in the coarse particles indicates their deposition from the atmosphere and soil contamination. This approach is useful for the assessment of the local resuspension influence on element’s contents in the aerosol and also for the evaluation of the historical pollution of soil caused by deposition of metals from the atmosphere