401 research outputs found
Evolution of Fermion Pairing from Three to Two Dimensions
We follow the evolution of fermion pairing in the dimensional crossover from
3D to 2D as a strongly interacting Fermi gas of Li atoms becomes confined
to a stack of two-dimensional layers formed by a one-dimensional optical
lattice. Decreasing the dimensionality leads to the opening of a gap in
radio-frequency spectra, even on the BCS-side of a Feshbach resonance. The
measured binding energy of fermion pairs closely follows the theoretical
two-body binding energy and, in the 2D limit, the zero-temperature mean-field
BEC-BCS theory.Comment: 5 pages, 4 figure
Motion of a Solitonic Vortex in the BEC-BCS Crossover
We observe a long-lived solitary wave in a superfluid Fermi gas of Li
atoms after phase-imprinting. Tomographic imaging reveals the excitation to be
a solitonic vortex, oriented transverse to the long axis of the cigar-shaped
atom cloud. The precessional motion of the vortex is directly observed, and its
period is measured as a function of the chemical potential in the BEC-BCS
crossover. The long period and the correspondingly large ratio of the inertial
to the bare mass of the vortex are in good agreement with estimates based on
superfluid hydrodynamics that we derive here using the known equation of state
in the BEC-BCS crossover
Overseas Chinese Environmental Engineers and Scientists Association (OCEESA) Report, Dec 2016.
This Overseas Chinese Environmental Engineers and Scientists Association (OCEESA) report is 2016 Directory of Overseas Chinese Environmental Engineers and Scientists Association (OCEESA), Report number: OCEESA/JL-2016/33D1, December 2016, ISSN 1072 -7248. This report was prepared by Yung-Tse Hung, Permanent Executive Director, OCEESA. This report includes OCEESA contact information, list of OCEESA Directors, list of OCEESA past presidents, OCEESA membership data, constitutions and by laws of OCEESA (5 November 2000 edition), constitutions and by laws of OCEESA (14 February 2006 edition), constitutions and by laws of OCEESA (27 October 2013 edition), membership application form, letter from Wen-Chi Ku to confirm Yung-Tse Hung OCEESA permanent executive director, letter from Lawrence Kong-Pu Wang to confirm Yung-Tse Hung OCEESA permanent executive director
Overseas Chinese Environmental Engineers and Scientists Association (OCEESA) Report, Regular Issue, February 2020
This OCEESA report, which is regular issue of OCEESA Journal (Overseas Chinese Environmental Engineers and Scientists Association Journal). This report is OCEESA report number: OCEESA/JL-2020/3701, February 2020, ISSN 1072 -7248. This report is also OCEESA Journal, Volume 37, Number 1, February 2020. Yung-Tse Hung, Permanent Executive Director, OCEESA, is editor of this report. This issue includes: (A) 10 OCEESA Best Papers (B) 6 OCEESA Papers; 21.Zhang-Zhi Charlie Huang 黄长志 , Implementing Compensation System for Environmental Damages: Challenges and Solutions, 22. Hanlu Yan, Kaimin Shih施凱閔 , Quantitative X-Ray Diffraction for Characterizing P Recovery Products from Wastewater, 23. Kaimin Shih 施凱閔 , Material Mineralogical Technology for Pollution Prevention and Resource Recovery材料礦物學技術於污染防治與資源回收的應用, 24. Kuo-Kunag Hsu 許國光 , Cleanup of MSW-Gasified Synthesis Gas, 25. Pao-Chiang Yuan 袁保強 , End of Useful Life Computer Recycling Program at Jackson State University, Jackson, Mississippi, USA, 26. Qin Qian钱琴, Bo Sun, Xianchang Li, Frank Sun, Che-Jen Lin, Water quality modeling with data collected by wireless sensor networks (WSNs) in an experimental pond: A case study; (C) 3 technical papers; 28. Abdulkarim Alorayfij, Yung-Tse Hung, Anaerobic digestion of agricultural waste, 29. Abdullah Alshati, Yung-Tse Hung, Methane Gas Production from Animal Waste, 30. Abdulmajeed Alshatti, Yung-Tse Hung, Treatment of Timber Industry Wastes, 31. OCEESA Constitutions By-Laws (5 November 2000 edition), 32. OCEESA Constitutions By-Laws (14 February 2006 edition), 33. OCEESA Constitutions By-Laws (27 October 2013 edition), 34. Lawrence Kong-Pu Wang letter of support Yung-Tse Hung Permanent Executive Director OCEESA 12-30-20, 35. Wen-Chi Ku letter of support Yung-Tse Hung Permanent Executive Director OCEESA 12-03-20, 36. OCEESA Member Application Form and Information, 37. Mailing Address Pag
Bacterial Meningitis in Infants
Neonatal bacterial meningitis is an uncommon but devastating infection. Although the incidence and mortality have declined over the last several decades, morbidity among survivors remains high. The types and distribution of causative pathogens are related to birth gestational age, postnatal age, and geographic region. Confirming the diagnosis of meningitis can be difficult. Clinical signs are often subtle, and the lumbar puncture is frequently deferred in clinically unstable infants. When obtained, confirmatory testing with cerebrospinal fluid (CSF) culture is often compromised by antepartum or postnatal antibiotic exposure. While blood cultures and CSF parameters may be helpful in cases where the diagnosis is uncertain, bacterial meningitis occurs in infants without bacteremia and with normal CSF parameters. Newer tests such as the polymerase chain reaction are promising but require further study. Prompt treatment with appropriate antibiotics is essential to optimize outcomes. Successful efforts to prevent meningitis in infants have included the use of intrapartum antibiotic prophylaxis against Group B Streptococcus (GBS). Clinical trials investigating the use of a GBS vaccine for the prevention of neonatal GBS disease are ongoing
A multidomain spectral method for solving elliptic equations
We present a new solver for coupled nonlinear elliptic partial differential
equations (PDEs). The solver is based on pseudo-spectral collocation with
domain decomposition and can handle one- to three-dimensional problems. It has
three distinct features. First, the combined problem of solving the PDE,
satisfying the boundary conditions, and matching between different subdomains
is cast into one set of equations readily accessible to standard linear and
nonlinear solvers. Second, touching as well as overlapping subdomains are
supported; both rectangular blocks with Chebyshev basis functions as well as
spherical shells with an expansion in spherical harmonics are implemented.
Third, the code is very flexible: The domain decomposition as well as the
distribution of collocation points in each domain can be chosen at run time,
and the solver is easily adaptable to new PDEs. The code has been used to solve
the equations of the initial value problem of general relativity and should be
useful in many other problems. We compare the new method to finite difference
codes and find it superior in both runtime and accuracy, at least for the
smooth problems considered here.Comment: 31 pages, 8 figure
Strongly interacting Fermi gases
Strongly interacting gases of ultracold fermions have become an amazingly rich test-bed for many-body theories of fermionic matter. Here we present our recent experiments on these systems. Firstly, we discuss high-precision measurements on the thermodynamics of a strongly interacting Fermi gas across the superfluid transition. The onset of superfluidity is directly observed in the compressibility, the chemical potential, the entropy, and the heat capacity. Our measurements provide benchmarks for current many-body theories on strongly interacting fermions. Secondly, we have studied the evolution of fermion pairing from three to two dimensions in these gases, relating to the physics of layered superconductors. In the presence of p-wave interactions, Fermi gases are predicted to display toplogical superfluidity carrying Majorana edge states. Two possible avenues in this direction are discussed, our creation and direct observation of spin-orbit coupling in Fermi gases and the creation of fermionic molecules of [superscript 23]Na [superscript 40]K that will feature strong dipolar interactions in their absolute ground state
Overseas Chinese Environmental Engineers and Scientists Association (OCEESA) Report, December 2016
This Overseas Chinese Environmental Engineers and Scientists Association (OCEESA) report is 2016 Directory of Overseas Chinese Environmental Engineers and Scientists Association (OCEESA), Report number: OCEESA/JL-2016/33D1, December 2016, ISSN 1072 -7248. This report was prepared by Yung-Tse Hung, Permanent Executive Director, OCEESA. This report includes OCEESA contact information, list of OCEESA Directors, list of OCEESA past presidents, OCEESA membership data, constitutions and by laws of OCEESA (5 November 2000 edition), constitutions and by laws of OCEESA (14 February 2006 edition), constitutions and by laws of OCEESA (27 October 2013 edition), membership application form, letter from Wen-Chi Ku to confirm Yung-Tse Hung OCEESA permanent executive director, letter from Lawrence Kong-Pu Wang to confirm Yung-Tse Hung OCEESA permanent executive director
Overseas Chinese Environmental Engineers and Scientists Association (OCEESA) Report, December 2019
This Overseas Chinese Environmental Engineers and Scientists Association (OCEESA) report is also 2019 Directory of Overseas Chinese Environmental Engineers and Scientists Association (OCEESA), Report number: OCEESA/JL-2019/36D1, December 2019, ISSN 1072 -7248. This report was prepared by Yung-Tse Hung, Permanent Executive Director, OCEESA. This report includes OCEESA contact information, list of 2019 OCEESA Directors, list of OCEESA past presidents, OCEESA membership data, constitutions and by laws of OCEESA (5 November 2000 edition), constitutions and by laws of OCEESA (14 February 2006 edition), constitutions and by laws of OCEESA (27 October 2013 edition), membership application form, letter from Wen-Chi Ku to confirm Yung-Tse Hung OCEESA permanent executive director, letter from Lawrence Kong-Pu Wang to confirm Yung-Tse Hung OCEESA permanent executive director
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