Tripartite quantum state mapping and discontinuous entanglement transfer in a cavity QED open system

We describe the transfer of quantum information and entanglement from three flying (radiation) to three localized (atomic) qubits via cavity modes resonantly coupled to the atoms, in the presence of a common reservoir. Upon addressing the full dynamics of the resulting nine-qubit open system, we find that once the cavities are fed, fidelity and transferred entanglement are optimal, while their peak values exponentially decrease due to dissipative processes. The external radiation is then turned off and quantum correlations oscillate between atomic and cavity qubits. For a class of mixtures of W and GHZ input states we deal with a discontinuous exchange of entanglement among the subsystems, facing the still open problem of entanglement sudden death and birth in a multipartite system.Comment: 7 pages, 6 figures, 2 table

Effect of dissolved oxygen and chemical oxygen demand to nitrogen ratios on the partial nitrification/denitrification process in moving bed biofilm reactors

Partial nitrification was reported to be technically feasible and economically favorable, especially for wastewater with high ammonium concentration or low C/N ratio. In this study, the effect of dissolved oxygen (DO) and influent ratio of chemical oxygen demand to nitrogen (COD/N) ratio on biological nitrogen removal from synthetic wastewater was investigated. Experiments were conducted in moving bed biofilm reactors (MBBRs) on partial nitrification process in pilot-plant configuration for 300 days. DO levels were changed from 0.04 to 0.12 and 0.42 to 3.4 mg/l in the anoxic (R1) and aerobic (R2) reactors, respectively. The optimum DO for partial nitrification was between 1-1.5 mg/l in the aerobic reactor (R2). Influent COD/N ratios between 20 and 2 g COD/g-N were tested by changing the nitrogen loading rate (NLR) supplied to the pilot plant. During operational conditions when the DO concentration in aerobic reactor was above 1 mg/l, near complete organic carbon removal occurred in the total MBBRs system. The effluent total nitrogen concentration in the operational conditions (1.7-2.1 mg O2/l and NH+ 4-N=35.7 mg N/l) was obtained in the range of 0.85-2 mg/l. The highest nitrite accumulation (50%- 52%) took place at the DO concentration of 1-1.5 mg/l and increased with decreasing COD/N ratio in aerobic reactor (R2). This study showed that the average nitrification rate at various COD/N ratios is about 0.96 gN/m2 per day while the maximum nitrification rate is about 2 gN/m2 per day at COD/N ratios lower than 6. The experimental COD/N ratio for denitrification was close to complete sum of NO2 - and NO3 - (NOx) removal efficiency (about 99%) at COD/N ratio equal 14 in the operational conditions in the anoxic reactor (R1)

Backscattering Differential Ghost Imaging in Turbid Media

In this Letter we present experimental results concerning the retrieval of images of absorbing objects immersed in turbid media via differential ghost imaging (DGI) in a backscattering configuration. The method has been applied, for the first time to our knowledge, to the imaging of small thin black objects located at different depths inside a turbid solution of polystyrene nanospheres and its performances assessed via comparison with standard imaging techniques. A simple theoretical model capable of describing the basic optics of DGI in turbid media is proposed.Comment: 5 pages, 6 figure

A motivation and effort model for members of wireless communities

The aim of this paper is to develop an analytical framework and model for understanding motivation and effort among members of Community-based WLANs. Wireless communities represent a stimulating area for research due to their organizational uniqueness as loosely-knit communities of wireless enthusiasts who cooperate to set up and operate a wireless communications infrastructure; in other words, they represent an example of collective action. Thus, two research issues are critical in understanding the mechanics behind the sustained existence of wireless communities: motivation – why individuals become community members – and coordination – how individuals within a community interact with each other. Focusing on the first issue, the paper provides a theoretical explanation of motivation which, in turn, informs the design of a conceptual model. According to this explanation, an individual decides to participate in a wireless community because of intrinsic as well as extrinsic motives. These motives are balanced against the perceived effort to join and participate in the community to jointly determine a suitable participation level for each community member. The resulting model adopts a cost-benefit (utility) perspective that is being empirically tested through a large-scale questionnaire survey

The coherent interaction between matter and radiation - A tutorial on the Jaynes-Cummings model

The Jaynes-Cummings (JC) model is a milestone in the theory of coherent interaction between a two-level system and a single bosonic field mode. This tutorial aims to give a complete description of the model, analyzing the Hamiltonian of the system, its eigenvalues and eigestates, in order to characterize the dynamics of system and subsystems. The Rabi oscillations, together with the collapse and revival effects, are distinguishing features of the JC model and are important for applications in Quantum Information theory. The framework of cavity quantum electrodynamics (cQED) is chosen and two fundamental experiments on the coherent interaction between Rydberg atoms and a single cavity field mode are described.Comment: 22 pages, 7 figures. Tutorial. Submitted to a special issue of EPJ - ST devoted to the memory of Federico Casagrand

Continuous-variable quantum probes for structured environments

We address parameter estimation for structured environments and suggest an effective estimation scheme based on continuous-variables quantum probes. In particular, we investigate the use of a single bosonic mode as a probe forOhmic reservoirs, and obtain the ultimate quantum limits to the precise estimation of their cutoff frequency. We assume the probe prepared in a Gaussian state and determine the optimal working regime, i.e., the conditions for the maximization of the quantum Fisher information in terms of the initial preparation, the reservoir temperature, and the interaction time. Upon investigating the Fisher information of feasible measurements, we arrive at a remarkable simple result: homodyne detection of canonical variables allows one to achieve the ultimate quantum limit to precision under suitable, mild, conditions. Finally, upon exploiting a perturbative approach, we find the invariant sweet spots of the (tunable) characteristic frequency of the probe, able to drive the probe towards the optimal working regime

Gambaran Persiapan Perawatan Fisik dan Mental pada Pasien Pre Operasi Kanker Payudara

Tujuan: Tujuan penelitian ini adalah untuk mengetahui gambaran perawatan persiapan fisik dan mental pada pasien pre operasi kanker payudara di RSMH Palembang Tahun 2011. Metode: Penelitian ini merupakan penelitian kuantitatif dengan desain penelitian yang digunakan adalah deskriptif analitik. Sampel penelitian ini adalah 4 orang penderita kanker payudara dan 16 orang perawat yang melakukan perawatan persiapan fisik dan mental. Hasil: Data yang dikumpulkan terdiri dari data primer dan data sekunder. Hasil penelitian didapatkan bahwa 3 pasien (75%) tidak siap menghadapi operasi, 12 perawat (75%) tidak melakukan perawatan persiapan fisik sesuai SOP dan 10 perawat (62.5%) tidak melakukan perawatan persiapan mental sesuai SOP serta dari hasil wawancara dengan 2 orang informan didapatkan 4 tema yaitu tahapan perawatan persiapan fisik, tahapan perawatan persiapan mental, kendala pelaksanaan perawatan persiapan fisik dan mental serta faktor yang mempengaruhi perawatan fisik dan mental. Simpula: Sehingga dapat disimpulkan bahwa perawatan persiapan fisik dan mental belum dilaksanakan dengan baik dan sesuai dengan SOP. Diharapkan bagi RSMH Palembang agar dapat lebih meningkatkan peran dari perawat dalam perawatan pasien kanker payudara khususnya perawatan persiapan fisik dan mental pada pasien pre operasi kanker payudara dengan cara memberikan pelatihan perawatan fisik dan mental

Comparision of zero-valent iron and activated carbon for treating chlorinated contaminants in groundwater

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1998.Includes bibliographical references (p. 65-67).by Bina M. Indelicato.M.Eng

Effectiveness of chitosan as natural coagulant aid in removal of turbidity and bacteria from turbid waters

There has been considerable interest in the development of natural coagulants such as chitosan. By using natural coagulants, considerable savings in chemicals and sludge handling cost may be achieved. Chitosan, a natural linear biopolyaminosaccharide, is obtained by alkaline deacetylation of chitin. Present study is aimed to examine the effects of aluminium sulfate (alum) as coagulant in conjunction with chitosan as coagulant aid on removal of turbidity and bacteria from turbid waters. These tests were carried out using artificial water and kaoline as model suspensions to represent the wide range of natural turbid waters. A conventional jar test apparatus was employed for the tests. After determining of optimum mixing intensity and duration, alum suspensions were added to the samples and after one minute, the desired doses of natural chitosan were added. In optimum condition, residual Al+3 in treated water was less than 0.2 mg/l and meets the EPA guidelines. Turbidity removal efficiency was 74.3- 98.2% by chitosan at a pH 7.0-7.5 for all turbidities. In addition, chitosan significantly reduced the required dosage of primary coagulant 50-87.5%. Bacteria reduction of 2-4 log units (99 - 99.99%) was obtained within the first 1 to 2 h of treatment. Overall results indicate that E.coli was removed better than S. faecalis. The main effects of coagulation by chitosan on bacteria are enmeshment and stack on the microbial cell surface. We demonstrated that optimal design method is an efficient approach for optimization of coagulation-flocculation process and appropriate for raw water treatment