188 research outputs found
Global High Resolution Crustal Magnetic Field at the Surface of the Moon from Low-Altitude Lunar Prospector Magnetic Gradient Data
We derived new vector gradients based models of crustal magnetic field at the lunar surface with data from the Lunar Prospector (LP) satellite using two model parameterization approaches: a global set of 35820 1 spaced (~30 km) equal area monopoles at 20 km below the surface (OBrien and Parker, 1994; Olsen et al., 2017) and combined results of subsets of 100000 0.66 spaced monopoles at the same depth. We use the scheme of iteratively reweighted least-squares inversion to compute the initial model. Then the amplitudes of these monopoles are determined by minimizing the misfit to the components together with the global average of |Br| at the ellipsoid surface (i.e. applying a L1 model regularization of Br). In previous approaches using vector fields for modeling, we found that external field contamination leads to spurious anomalies in the downward continued field models even with stringent data selection criteria and ad-hoc noise removal techniques (e.g., satellites position in the Moons wake w.r.t. the solar wind and in the Earths magnetotail, internal/external dipoles fields removal, low-order polynomial removal, joint equivalent source cross-validation technique and visually removing remaining anomalous segments). On the other hand, with the use of gradients-only data (along-track first finite differences), we were able to completely bypass the ad-hoc techniques. Similar processing of Kaguya magnetic data, which have only higher altitude coverage over the most of the Moon except in the region of the South PoleAitken (SPA) basin, completely misses some of the anomalies seen in the Lunar Prospector data. The combined Lunar Prospector and Kaguya gradient-based models also severely degrade the derivation of the anomaly fields in many regions. Euler analysis of isolated anomaly features from the Reiner Gamma swirl suggests top depths of about 0.3 to 1.5 km and center depths of 10-14 km; in the region between Stein and Vallier craters north of the SPA basin our analysis suggests top depths of around 1.5 km and center depths of 13-15 km. With the spectral depth determination techniques, the SPA basin region yields depths to the base of magnetization ranging between 15 and 40 km. Three-dimensional modeling and the bulk magnetization determinations of the sources constrained by the Euler and spectral methods is underway
Malaria Clusters among Illegal Chinese Immigrants to Europe through Africa
Between November 2002 and March 2003, 17 cases of malaria (1 fatal) were observed in illegal Chinese immigrants who traveled to Italy through Africa. A further cluster of 12 was reported in August, 2002. Several immigrants traveled by air, making the risk of introducing sudden acute respiratory syndrome a possibility should such illegal immigrations continue
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Evaluation of the computerized utilities and energy monitoring and control system installed at the US Army, Europe, 222D Base Support Battalion, Baumholder, Germany
ORNL the utilities and energy monitoring and control systems (UEMCSs) installed at the 222D Base Support Battalion (BSB) at Baumholder, Germany. This evaluation relies on examination of existing data and information to determine the effectiveness of the UEMCSs. The Baumholder BSB consists of numerous installations located as far as 63 miles from the principal installation at Baumholder. Only five facilities within these installations currently have support from four essentially separate UEMCSs A Messner/Miles and two Honeywell systems, which combined have 4600 points serving 200 buildings, perform traditional UEMCS functions associated with district heating, while a Landis & Gyr UEMCS is used exclusively for electrical demand limiting and exterior lighting control. Total energy consumption at the community has steadily decreased since 1986 because of the implementation of UEMCS and the conversion to district heat. However, lack of annual energy consumption data by individual installation makes direct association of energy reductions to the implementation of specific UEMCSs difficult. Engineering estimates predict approximately a 6% annual energy savings associated with the UEMCSs of DM 1.9 million. However, less than 40% of the total community building area is connected. Opportunities for additional savings are available through (1) expanded use of demand limiting, (2) increased memory for the older Honeywell system to allow extending its application at the Smith Barracks facility and facilities nearby, (3) use of available UEMCS equipment to shut off the domestic hot water circulation pumps at night, (4) extension of UEMCS control at the Neubruecke Hospital complex, and (5) installation and utilization of heating hot water and potable hot water leak detection equipment. A moderate effort to track energy consumption by facility should be undertaken and data transmission lines associated with the UEMCS inspected and repaired
Magnetization of the Lunar Crust
Magnetic fields measured by the satellite Lunar Prospector show large scale features resulting from remanently magnetized crust. Vector data synthesized at satellite altitude from a spherical harmonic model of the lunar crustal field, and the radial component of the magnetometer data, have been used to produce spatially continuous global magnetization models for the lunar crust. The magnetization is expressed in terms of localized basis functions, with a magnetization solution selected having the smallest root-mean square magnetization for a given fit to the data, controlled by a damping parameter. Suites of magnetization models for layers with thicknesses between 10 and 50 km are able to reproduce much of the input data, with global misfits of less than 0.5 nT (within the uncertainties of the data), and some surface field estimates. The magnetization distributions show robust magnitudes for a range of model thicknesses and damping parameters, however the magnetization direction is unconstrained. These global models suggest that magnetized sources of the lunar crust can be represented by a 30 km thick magnetized layer. Average magnetization values in magnetized regions are 30-40 mA/m, similar to the measured magnetizations of the Apollo samples and significantly weaker than crustal magnetizations for Mars and the Earth. These are the first global magnetization models for the Moon, providing lower bounds on the magnitude of lunar crustal magnetization in the absence of multiple sample returns, and can be used to predict the crustal contribution to the lunar magnetic field at a particular location
Mercury's Magnetopause and Bow Shock from MESSENGER Magnetometer Observations
We have established the average shape and location of Mercury's magnetopause and bow shock from orbital observations by the MESSENGER Magnetometer. We fit empirical models to midpoints of boundary crossings and probability density maps of the magnetopause and bow shock positions. The magnetopause was fit by a surface for which the position R from the planetary dipole varies as [1 + cos(theta)]-alpha, where theta is the angle between R and the dipole-Sun line, the subsolar standoff distance Rss is 1.45 RM (where RM is Mercury's radius), and the flaring parameter alpha = 0.5. The average magnetopause shape and location were determined under a mean solar wind ram pressure PRam of 14.3 nPa. The best fit bow shock shape established under an average Alfvén Mach number (MA) of 6.6 is described by a hyperboloid having Rss = 1.96 RM and an eccentricity of 1.02. These boundaries move as PRam and MA vary, but their shapes remain unchanged. The magnetopause Rss varies from 1.55 to 1.35 RM for PRam in the range of 8.8-21.6 nPa. The bow shock Rss varies from 2.29 to 1.89 RM for MA in the range of 4.12-11.8. The boundaries are well approximated by figures of revolution. Additional quantifiable effects of the interplanetary magnetic field are masked by the large dynamic variability of these boundaries. The magnetotail surface is nearly cylindrical, with a radius of ~2.7 RM at a distance of 3 RM downstream of Mercury. By comparison, Earth's magnetotail flaring continues until a downstream distance of ~10 Rss
MESSENGER observations of Mercury's magnetic field structure
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96229/1/jgre3136.pd
Plasma pressure in Mercury's equatorial magnetosphere derived from MESSENGER Magnetometer observations
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95264/1/grl28621-sup-0002-txts01.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/95264/2/grl28621.pd
Low‐degree structure in Mercury's planetary magnetic field
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96330/1/jgre3134.pd
The Clinical Translation Gap in Child Health Exercise Research: A Call for Disruptive Innovation
In children, levels of play, physical activity, and fitness are key indicators of health and
disease and closely tied to optimal growth and development. Cardiopulmonary exercise
testing (CPET) provides clinicians with biomarkers of disease and effectiveness of
therapy, and researchers with novel insights into fundamental biological mechanisms
reflecting an integrated physiological response that is hidden when the child is at rest.
Yet the growth of clinical trials utilizing CPET in pediatrics remains stunted despite the
current emphasis on preventative medicine and the growing recognition that therapies
used in children should be clinically tested in children. There exists a translational gap
between basic discovery and clinical application in this essential component of child
health. To address this gap, the NIH provided funding through the Clinical and
Translational Science Award (CTSA) program to convene a panel of experts. This
report summarizes our major findings and outlines next steps necessary to enhance
child health exercise medicine translational research. We present specific plans to
bolster data interoperability, improve child health CPET reference values, stimulate
formal training in exercise medicine for child health care professionals, and outline
innovative approaches through which exercise medicine can become more accessible
and advance therapeutics across the child health spectrum
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