435 research outputs found
Photonic interface for long-distance entanglement of logical-qubits
A scalable fault-tolerant quantum-computer hardware with current noisy
intermediate-scale quantum (NISQ) devices requires the juxtaposition of
different types of quantum systems. In this sense, long-distance entanglement
of stationary error-corrected logical qubits requires a photonic bus
facilitating inter/intra-connection among the cores of quantum processors, the
units of quantum memories, and the worldwide quantum internet. This article
proposes a photonic interface for 4 and 6-qubit encoding of surface-code
logical-qubits in an atomic-lattice platform. Accommodating the lattice inside
a cavity, the gate emits photonic-qubits that are entangled by the
logical-qubits. The entangling mechanism is provided by the Fermi scattering of
a Rydberg electron from the plaquette atoms trapped in a qubit-dependent
lattice. Therefore, different arrangements of logical-qubits derive the central
atom over distinguished eigenstates, featuring photon emission at the early or
late times distinguished by quantum interference. Finally, entanglement
swapping of two emitted photons would make the far separated plaquettes
entangled in the logical basis.Comment: arXiv admin note: text overlap with arXiv:2111.0158
All optical quantum information processing via a single step Rydberg blockade gate
One of the critical elements in the realization of the quantum internet are
deterministic two-photon gates. This photonic gate also completes a set of
universal gates for all-optical quantum information processing. This article
discusses an approach to realize high fidelity photonic gate by storing
both control and target photons within an atomic ensemble using non-Rydberg
electromagnetically induced transparency (EIT) followed by a fast, single-step
Rydberg excitation with global lasers. The proposed scheme operates by relative
intensity modulation of two lasers used in Rydberg excitation. Circumventing
the conventional -gap- schemes, the proposed operation features
continuous laser protection of the Rydberg atoms from the environment noise.
The complete spatial overlap of stored photons inside the blockade radius
optimizes the optical depth and simplifies the experiment. The coherent
operation here is performed in the region that was dissipative in the previous
Rydberg EIT schemes. Encountering the main imperfection sources, i.e. the
spontaneous emission of the Rydberg and intermediate levels, population
rotation errors, Doppler broadening of the transition lines, storage/retrieval
efficiency, and atomic thermal motion induced decoherence, this article
concludes that with realistic experimental parameters 99.7\% fidelity is
achievable
Thermal Effects for Shaft-Pre-Stress on Rotor Dynamic System
This Paper outlines study behaviour of rotating shaft with high speed under
thermal effects. The method of obtaining the frequency response functions of a
rotor system with study whirl effect in this revision the raw data obtained
from the experimental results (using Smart Office program) are curve-fitted by
theoretical data regenerated from some of the experimental data and simulating
it using finite element (ANSYS 12). (FE) models using the Eigen analysis
capability were used to simulate the vibration. The results were compared with
experimental data show analysis data with acceptable accuracy and performance.
The rotating effect causes un-symmetry in the system matrices, resulting in
complexity in decoupling the mathematical models of the system for the purpose
of modal analysis. Different method is therefore required, which can handle
general system matrices rather than symmetrical matrices, which is normal for
passive structures. Mathematical model of the system from the test data can be
assembled. The frequency response functions are extracted, Campbell diagram are
draw and simulated. (FE) is used to carry out such as simulation since it has
good capability for Eigen analysis and also good graphical facility.
Keywords: Thermal effects, Modelling, Campbell diagram, Whirl, Rotor
dynamics.Comment: Published by: Academic Research Publishing Agency. All rights
reserved, 6 pages, 4 figures, 1 pictur
Distributional Characteristics And Stochastic Dominance versus Parametric Analysis In Testing Anomalies In The Emerging Market: Evidence From Jordan
Virtually all previous studies of seasonal variation in stock returns have used mean/variance analysis despite it being well documented that stock returns in developed and emerging markets are non-normally distributed. This paper details the distributional characteristics of emerging Amman financial market returns. Further more, it uses stochastic dominance and parametric analyses to investigate the turn-of-the-year and the-week effects from 1978 to 2001.  Results indicate that returns of Amman financial market exhibit substantial deviation from normality. And parametric analysis tests show there is January and week effects. However, stochastic dominance results indicate that January and week effects are not exist in the AFM. This implies that the results of parametric analysis are being driven by violations of parametric assumptions
Academic Course Management System (ACMS)
This project provides solutions for the Course Management System currently being used by UTP
thru its website to handle academic matters involving students, lecturers and academic staffs.
The problem is the system is unsecured by without having proper authentication like validation
control and login page that enables anybody to hack into the system and manipulate the contents.
Next is unreliability of transactions' data processing and information displaying where the result
is not displayed instantly to students and sometimes the result is incorrect and contains wrong
information. The significances are the student won't be able to see the latest the transactions'
result instantly and incorrect information display. Motivations on these problems are derived
from the author when experiencing the common problems like other students. Furthermore, these
problems occur every semester; creating displeasure feeling and reducethe trust of users towards
the system. Main intentions of this project are to improve the performance of data processing
speed, reduce system error in data input and output display, and eliminate traditional process of
lab registration. It is also for simplifying and reducing the number of process transactions and to
enhance usability and navigation structure by users towards web based applications design. The
project implements re-engineering concept where the objective is to breakdown the modules,
improve and enhance the necessary parts, restructure them back and come out withtotally better
system. Visual Studio.NET software is usedto design the webapplication and function while the
programming language used is called ASP.NET. The theories gathered from researches
conducted are valuable to understood on how to evaluate the potential elements of web usability
and to further understand users' requirements. This project covers basic ways of providing
security using ASP.NET technology and the elements used to improve the users' pleasure and
functionalities expected within education environment at higher education institution. As results,
good web based application design are implemented, security method and procedure is
developed and provided, data and information is processed faster and displayed accurately, the
levels of transaction processes are reduced and also improvements towards system performance
and functionalities in navigation and lowering the frequency of problem occurrence. For future
work, the integration with mobile devices, SMS or email features in notification and combined
together with E-Learning system are strongly recommended for potential improvements and
hence more flexibility usage
A study of configurational alternatives of a gas-to-liquids process based on Fischer-Tropsch technology
Environmental concerns, associated legislation, limited oil reserves and fluctuating crude oil prices are some of the factors that highlight the need for alternative and environmentally friendly routes to fuels. One alternative is to use Fischer-Tropsch Synthesis (FTS) as the major technology in conversion of carbon containing feedstock to transportation fuels. The FTS product, called syncrude, can be refined to high quality transportation fuels in Coal, Gas or Biomass to liquid plants (denoted as CTL, GTL, and BTL, respectively, and collectively referred to as XTL). The economic viability of XTL processes is generally subject to the present price of crude oil and past studies show that traditional refining is generally more economically viable. However, XTL processes have been shown to be more economical and in some cases more environmentally friendly than conventional options when legislative measures aiming to curb traditional fossil fuel usage are considered. This study explores XTL process configurations that can improve plant carbon efficiency to diesel and liquids. The configuration encompasses technologies used, operating conditions, and layout of unit operations. A basic GTL process configuration consists of an Air Separation Unit (ASU), Auto-Thermal Reforming (ATR), syngas cleaning, full conversion Low Temperature Fischer-Tropsch (LTFT) and wax hydrocracking (WHC). These operations are modeled individually and combined to produce a plant model for study with the aim of determining the effects of configurational alternatives on the process efficiency to liquids and diesel. Furthermore, given that the ASU is a major contributor to costs the effect of using oxygen-enriched or pure air is investigated. Since production of heavy wax is prioritized, FTS represents the use of cobalt catalyst in LTFT operation. Where air is used, FTS is run to high conversion in once through mode to avoid the unfavorable economics of recycling nitrogen. After separation of the syncrude, the light fraction is reformed back to syngas in order to maximize carbon efficiency. The heavy wax is hydrocracked to maximize distillate range material. The light products from the WHC are combined with the lights from FTS and the heavy wax is recycled. Carbon efficiency, liquid selectivity and diesel yield are the means of assessing performance. The Scilab programming language is used along with physical properties estimated using the COCO/ChemSep pure component database as a starting point. Estimation of properties for alkanes and olefins of carbon chain length up to C200 has been carried out. The presence of 25% nitrogen in the ATR was found to beneficial to the H2 : CO ratio in the resulting syngas. Furthermore, in FTS the presence of 10-20% nitrogen produced the lowest reduction in carbon monoxide conversion and _FTS. In general, the introduction of nitrogen resulted in decreased conversion of methane in the ATR and both decreased _FTS and conversion in FTS. WHC performance was found to benefit from alpha being as high as possible; however, when the heavy wax recycle was inactive the optimal value was 0.92. The OOT80 configuration was found to have the highest liquid selectivity, while the efficiency to diesel was maximized for the OIRC40 configuration
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