267 research outputs found
Observations of the Total Solar Eclipse of June 8, 1918, at Matheson, Colorado
The Drake University Observatory eclipse expedition occupied a very favorable site at Matheson, Colorado. It was wholly through the courtesy of Dr. Edwin B. Frost, Director of the Yerkes Observatory, who with Prof. E. E. Barnard, had selected this station as one of two very desirable locations, that the expedition was so happily situated
Photographic Accessories of the Drake Observatory
The application of photography to astronomical research is one of the great achievements of science. While the pioneering experiments date back to the days of Dr. J. W. Draper and Warren de la Rue, the vastly interesting and valuable results belong to the present decade. Astro-physics, the new-born child of Astronomy\u27\u27, owes its phenomenal growth and development, if not its birth, to the photographic lens and camera
The Hysteresis Loop
It is not proposed to introduce a new method for the determination of the hysteresis loop, but to introduce some advantageous modifications. The method is similar to the ring ballistic method outlined by Dr. R. A. Millikan. This method has the advantage over the old magnetometer method in that the lines of force are continuous through the iron. It cannot be used however if the iron is hard and causes any creeping
Star Count in the Dark Ring Nebula in Cygnus
To our knowledge the first time this Bird\u27s Nest marking was considered as a possible ring of absorbing nebulosity was in 1910 when the senior author noticed the object and mentioned the possibility that it might be an actual ring of dark absorbing nebulosity. The ring is conspicuously evident upon every exposure of long enough duration to exhibit such markings. It is located in the Labrador section of the North America Nebula, right ascension 20 hours, 52 minutes, declination plus 45 degrees. Its external diameter is about thirty minutes of arc and its internal diameter about twelve minutes of arc
The Address of the President - The Cosmology of the Universe
Astronomy is the original science. Its scope comprehends all the physical sciences - geology, physics, chemistry - and even the natural sciences. All borrow from it, and in turn contribute to astronomical knowledge. Moreover, from the very beginning, the study of astronomy has been inseparably connected with philosophy and religious speculation. For its theme - its age-long objective - has been a true world concept. I quote: Back of every religion, and of every philosophy or science, worthy of the name, lies a world-view, a concept in which are included all localities and all beings supposed in that religion or philosophy or science to exist. In proportion to its clearness and completeness it, in every case, groups and mentally pictures these localities and beings in certain relations to each other, and thus also in their total unity as a universe. The science which critically investigates and expounds the world-view of any people or of any system of doctrine is called cosmology
The Dark Ring Nebula in Cygnus
Since my report on the Dark Ring Nebula in Cygnus,1 I have received the following communication from Dr. R. H. Curtiss, Acting Director of the Detroit Observatory of the University of Michigan: Your article in the February Popular Astronomy on a dark ring nebula in Cygnus has led me to look up an excellent slide which we have of that region made from a photograph secured with the 6-inch Willard Lens on October 5, 1893, at Lick Observatory. The dark elliptical ring stands out very beautifully on this slide. I think anyone would notice it but would be strongly tempted to ascribe it to a defect in one of the pieces of glass through which light must pass in making the lantern slide copy.
Direct health care costs of treating seasonal affective disorder: a comparison of light therapy and fluoxetine.
Objective. To compare the direct mental health care costs between individuals with Seasonal Affective Disorder randomized to either fluoxetine or light therapy. Methods. Data from the CANSAD study was used. CANSAD was an 8-week multicentre double-blind study that randomized participants to receive either light therapy plus placebo capsules or placebo light therapy plus fluoxetine. Participants were aged 18-65 who met criteria for major depressive episodes with a seasonal (winter) pattern. Mental health care service use was collected for each subject for 4 weeks prior to the start of treatment and for 4 weeks prior to the end of treatment. All direct mental health care services costs were analysed, including inpatient and outpatient services, investigations, and medications. Results. The difference in mental health costs was significantly higher after treatment for the light therapy group compared to the medication group-a difference of 75.41 (z = -2.635, P = 0.008). Conclusion. The results suggest that individuals treated with medication had significantly less mental health care cost after-treatment compared to those treated with light therapy
Direct Health Care Costs of Treating Seasonal Affective Disorder: A Comparison of Light Therapy and Fluoxetine
Objective. To compare the direct mental health care costs between individuals with Seasonal Affective Disorder randomized to either fluoxetine or light therapy. Methods. Data from the CANSAD study was used. CANSAD was an 8-week multicentre double-blind study that randomized participants to receive either light therapy plus placebo capsules or placebo light therapy plus fluoxetine. Participants were aged 18–65 who met criteria for major depressive episodes with a seasonal (winter) pattern. Mental health care service use was collected for each subject for 4 weeks prior to the start of treatment and for 4 weeks prior to the end of treatment. All direct mental health care services costs were analysed, including inpatient and outpatient services, investigations, and medications. Results. The difference in mental health costs was significantly higher after treatment for the light therapy group compared to the medication group—a difference of 75.41 (z = −2.635, P = 0.008). Conclusion. The results suggest that individuals treated with medication had significantly less mental health care cost after-treatment compared to those treated with light therapy
Test ion transport in a collisional, field-reversed configuration
Diffusion of test-ions in a flux-coil generated, collisional, field-reversed configuration is measured via time-resolved tomographic reconstruction of Ar+ optical emission in the predominantly nitrogen plasma. Azimuthal test ion diffusion across magnetic field lines is found to be classical during the stable period of the discharge. Test ion radial confinement is enhanced by a radial electric field, reducing the observed outward radial transport rate below predictions based solely on classical cross-field diffusion rates. Test ion diffusion is ∼500m2s-1 during the stable period of the discharge. The electric field inferred from plasma potential measurements and from equilibrium calculations is consistent with the observed reduction in argon transport. © 2014 IOP Publishing Ltd
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