459 research outputs found
Tunable, single-frequency, erbium fiber ring lasers
Tuning range, side-mode suppression, line width, and intensity noise are reviewed for an all-fiber erbium ring laser. Active stabilization to an external fiber Fabry-Perot resonator is demonstrated
Reduction of the intensity noise from an erbium-doped fiber laser to the standard quantum limit by intracavity spectral filtering
The high frequency intensity noise of a tandem fiber Fabry–Perot erbium-doped fiber ring laser is reduced to the standard quantum limit, with a 0.5 dB experimental uncertainty. Noise reduction of >~14 dB is achieved by intracavity spectral filtering of weak side modes using a narrow-band fiber Fabry–Perot etalon
Measurements of the intensity noise of a broadly tunable, erbium-doped fiber ring laser, relative to the standard quantum limit
The intensity noise of an erbium-doped fiber ring laser is measured relative to the standard quantum limit. Over a tuning range of 24 nm, the noise power is within 20 dB of the shot noise floor and varies linearly with laser output power. Oscillations in the noise power spectrum are observed and attributed to beating of the lasing mode with other, strongly damped cavity modes
IS 502 Christian Formation: Vocation of Ministry
Grenz, S. & Bell, R. (1995). Betrayal of Trust: Sexual Misconduct in the Pastorate. Downers Grove, IL: InterVarsity Press. Groothuis, R.M. (1997). Good new for women: A biblical picture of gender equality, Grand Rapids, MI: Baker; 19-63;121-144;189-229. [Chapters 1, 2, 5, 8, 9] Guiness, O. (1998). The Call: Finding and Fulfilling the Central Purpose of Your Life. Waco,TX: Word. Sire, J. Habits of the Mind. Downers Grove, IL: InterVarsity Press Smith, G. (1997). Listening to God in Times of Choice, Downers Grove, IL: InterVarsity Press. Foster, R. (1998). Celebration of Discipline, New York: Harper and Row. Foster, R. (1998). Celebration of Discipline Study Guide, New York: Harper and Row Willimon William, H., Calling and Character: Virtues of the Ordained Life, Nashville: Abingdon Press, 2000https://place.asburyseminary.edu/syllabi/2669/thumbnail.jp
Discovery of a Color-Selected Quasar at z=5.50
We present observations of RD J030117+002025, a quasar at z=5.50 discovered
from deep, multi-color, ground-based observations covering 74 square arcmin.
This is the most distant quasar or AGN currently known. The object was targeted
as an R-band dropout, with R(AB)>26.3 (3-sigma limit in a 3 arcsec diameter
region), I(AB)=23.8, and z(AB)=23.4. The Keck/LRIS spectrum shows broad
Lyman-alpha/NV emission and sharp absorption decrements from the
highly-redshifted hydrogen forests. The fractional continuum depression due to
the Lyman-alpha forest is D(A)=0.90. RD J030117+002025 is the least luminous,
high-redshift quasar known (M(B)~-22.7).Comment: 9 pages, 2 figures; to appear in the The Astrophysical Journal
Letter
The forgotten '45 : Donald Dubh's rebellion in an archipelagic context
The final rebellion of Donald Dubh, heir to the forfeited MacDonald lordship of the Isles, is usually examined within the context of Highland rebellions that occurred in the half century after forfeiture. However, the factors that motivated the Islesmen to rise in rebellion in 1545 are multi-faceted and can only be fully understood by placing the rising in a wider context, which considers national and archipelagic events. The discussion that follows explores the reasons why the Islesmen, almost unanimously, entered into agreement with Henry VIII to attack Scotland from the west and why this endeavour failed. At the same time, the article highlights Henry’s recognition of the strategic importance of the west which led him into alliance with Donald Dubh and his supporters
Seizing the Moment: Realizing the Promise of Student-Centered Learning
This brief outlines policy recommendations for supporting student-centered learning at the local, state, and federal level
CT Scan Merging to Enhance Navigation in Interventional Radiology Simulation
International audienceWe present a method to merge two distinct CT scans acquired from dif- ferent patients such that the second scan can supplement the first when it is missing necessary supporting anatomy. The aim is to provide vascular intervention simula- tions with full body anatomy. Often, patient CT scans are confined to a localised region so that the patient is not exposed to more radiation than necessary and to increase scanner throughput. Unfortunately, this localised scanning region may be limiting for some applications where surrounding anatomy may be required and where approximate supporting anatomy is acceptable. The resulting merged scan can enhance body navigation simulations with X-ray rendering by providing a com- plete anatomical reference which may be useful in training and rehearsal. An ex- ample of the use of our CT scan merging technique in the field of interventional radiology is described
Spectroscopic Properties of the z=4.5 Lyman-alpha Emitters
We present Keck/LRIS optical spectra of 17 Lya-emitting galaxies and one
Lyman break galaxy at z=4.5 discovered in the Large Area Lyman Alpha (LALA)
survey. The survey has identified a sample of ~350 candidate Lya-emitting
galaxies at z=4.5 in a search volume of 1.5 x 10^6 comoving Mpc^3. We targeted
25 candidates for spectroscopy; hence, the 18 confirmations presented herein
suggest a selection reliability of 72%. The large equivalent widths (median
W(rest)~80 A) but narrow physical widths (v < 500 km/s) of the Lya emission
lines, along with the lack of accompanying high-ionization state emission
lines, suggest that these galaxies are young systems powered by star formation
rather than by AGN activity. Theoretical models of galaxy formation in the
primordial Universe suggest that a small fraction of Lya-emitting galaxies at
z=4.5 may still be nascent, metal-free objects. Indeed, we find with 90%
confidence that 3 to 5 of the confirmed sources show W(rest) > 240 A, exceeding
the maximum Lya equivalent width predicted for normal stellar populations.
Nonetheless, we find no evidence for HeII 1640 emission in either individual or
composite spectra, indicating that though these galaxies are young, they are
not truly primitive, Population III objects.Comment: 12 pages, Accepted to Ap
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