25 research outputs found
Laser Cooling of Transition Metal Atoms
We propose the application of laser cooling to a number of transition-metal
atoms, allowing numerous bosonic and fermionic atomic gases to be cooled to
ultra-low temperatures. The non-zero electron orbital angular momentum of these
atoms implies that strongly atom-state-dependent light-atom interactions occur
even for light that is far-detuned from atomic transitions. At the same time,
many transition-metal atoms have small magnetic dipole moments in their
low-energy states, reducing the rate of dipolar-relaxation collisions.
Altogether, these features provide compelling opportunities for future
ultracold-atom research. Focusing on the case of atomic titanium, we identify
the metastable state as supporting a optical
transition with properties similar to the D2 transition of alkali atoms, and
suited for laser cooling. The high total angular momentum and electron spin of
this state suppresses leakage out of the the nearly closed optical transition
to a branching ratio estimated below . Following the pattern
exemplified by titanium, we identify optical transitions that are suited for
laser cooling of elements in the scandium group (Sc, Y, La), the titanium group
(Ti, Zr), the vanadium group (V, Nb), the manganese group (Mn, Tc), and the
iron group (Fe, Ru).Comment: 12 pages, 6 figure
Optical Telecommunications-Band Clock based on Neutral Titanium Atoms
We propose an optical clock based on narrow, spin-forbidden M1 and E2
transitions in laser-cooled neutral titanium. These transitions exhibit much
smaller black body radiation shifts than those in alkaline earth atoms, small
quadratic Zeeman shifts, and have wavelengths in the S, C, and L-bands of
fiber-optic telecommunication standards, allowing for integration with robust
laser technology. We calculate lifetimes; transition matrix elements; dynamic
scalar, vector, and tensor polarizabilities; and black body radiation shifts of
the clock transitions using a high-precision relativistic hybrid method that
combines a configuration interaction and coupled cluster approaches. We also
calculate the line strengths and branching ratios of the transitions used for
laser cooling. To identify magic trapping wavelengths, we have completed the
largest-to-date direct dynamical polarizability calculations. Finally, we
identify new challenges that arise in precision measurements due to magnetic
dipole-dipole interactions and describe an approach to overcome them. Direct
access to a telecommunications-band atomic frequency standard will aid the
deployment of optical clock networks and clock comparisons over long distances.Comment: 5 pages, 2 figures main text; 8 pages, 3 figures supplementary tex
Case Series of Synthetic Cannabinoid Intoxication from One Toxicology Center.
Synthetic cannabinoid use has risen at alarming rates. This case series describes 11 patients exposed to the synthetic cannabinoid, MAB-CHMINACA who presented to an emergency department with life-threatening toxicity including obtundation, severe agitation, seizures and death. All patients required sedatives for agitation, nine required endotracheal intubation, three experienced seizures, and one developed hyperthermia. One developed anoxic brain injury, rhabdomyolysis and died. A significant number were pediatric patients. The mainstay of treatment was aggressive sedation and respiratory support. Synthetic cannabinoids pose a major public health risk. Emergency physicians must be aware of their clinical presentation, diagnosis and treatment
Adaptive radar waveform synthesis via alternating projections.
As the number of wireless broadband devices occupying our airwaves grows at a rapid rate, the resultant decrease in available spectrum for current technologies and increasingly stringent regulations on band compliance has necessitated adaptive RF technologies which can respond to the spectrum crisis. The task of maintaining the effectiveness of our RF technology with a shrinking spectrum has generated work in a number of fields, notably cognitive radar. This work focuses on developing an algorithm which can adaptively produce waveforms with desired accuracy in the range-Doppler domain, measured by the ambiguity function, for radar detection while also having characteristics which allow for efficient amplifier operation and spectral compliance
A Model for SIFT Optimization Using FPAA-Driven Block Convolution
The Scale Invariant Feature Transform (SIFT) is a useful algorithm for describing local features in an image. This research successfully demonstrates a model for optimizing SIFT using a Field Programmable Analog Array (FPAA). A method is presented which theoretically can reduce SIFT run time by nearly 50% by greatly limiting the image area required to search for SIFT features. Block convolution is a simplified, non-overlapping method of convolution which is computed with the
FPAA. The block convolution between the input image and a specially designed kernel is used to determine potential regions of interest. The performance of several different types of kernels will be compared, most of which were produced using an evolutionary search algorithm. A threshold is then applied to the filtered image produced by the FPAA and regions which are unlikely to produce matches are masked. By removing the necessity to search in areas of the image where a match is unlikely to be found, we see a more efficient implementation of SIFT that also demonstrates the usefulness of new FPAA technology
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Optical telecommunications-band clock based on neutral titanium atoms
We propose an optical clock based on ultranarrow transitions in neutral titanium, which exhibit small blackbody radiation and quadratic Zeeman shifts and have wavelengths in the S-, C-, and L-telecommunications fiber bands, allowing for integration with robust laser technology. We calculate relevant properties using a high-precision relativistic hybrid method that combines configuration interaction and coupled-cluster approaches. To identify magic wavelengths, we have completed the largest-to-date direct dynamical polarizability calculations. Finally, we identify challenges that arise from magnetic dipole-dipole interactions and describe an approach to overcome them. A telecommunications-band atomic frequency standard will aid the deployment of optical clock networks and clock comparisons over long distances
Case Series of Synthetic Cannabinoid Intoxication from One Toxicology Center
Synthetic cannabinoid use has risen at alarming rates. This case series describes 11 patients exposed to the synthetic cannabinoid, MAB-CHMINACA who presented to an emergency department with life-threatening toxicity including obtundation, severe agitation, seizures and death. All patients required sedatives for agitation, nine required endotracheal intubation, three experienced seizures, and one developed hyperthermia. One developed anoxic brain injury, rhabdomyolysis and died. A significant number were pediatric patients. The mainstay of treatment was aggressive sedation and respiratory support. Synthetic cannabinoids pose a major public health risk. Emergency physicians must be aware of their clinical presentation, diagnosis and treatment
Case Series of Synthetic Cannabinoid Intoxication from One Toxicology Center
Synthetic cannabinoid use has risen at alarming rates. This case series describes 11 patients exposed to the synthetic cannabinoid, MAB-CHMINACA who presented to an emergency department with life-threatening toxicity including obtundation, severe agitation, seizures and death. All patients required sedatives for agitation, nine required endotracheal intubation, three experienced seizures, and one developed hyperthermia. One developed anoxic brain injury, rhabdomyolysis and died. A significant number were pediatric patients. The mainstay of treatment was aggressive sedation and respiratory support. Synthetic cannabinoids pose a major public health risk. Emergency physicians must be aware of their clinical presentation, diagnosis and treatment