Infrared emission from ultracompact H II regions

Models of circumstellar dust shells around ultracompact (UC) H II regions were constructed that accurately fit the observed IR flux distributions. The models assume spherically symmetric dust shells illuminated by stars whose bolometric luminosity is inferred from the integrated FIR flux densities. Assuming ionization by a single zero age main sequence (ZAMS) star, the relations of Panagia were used to infer the stellar radius and effective temperature for a given luminosity. The grain mixture in the dust shell consists of bare graphite and silicate grains with the optical properties of Draine and Lee and the size distribution of Mathis et al. The computer code of Wolfire et al was used to solve the radiative transfer equations through a spherical dust shell. The model provides monochromatic luminosities, dust temperatures, and opacities through the shell. Aside from the stellar and dust properties, the only other input parameters to the model are the distance to the shell, the form of its density distribution, and its outer radius. Predictions of the model are compared with observations of a typical UC H II region and the run of dust temperature with radius and the optical depth with frequency are discussed

Static Envelope Patterns in Composite Resonances Generated by Level Crossing in Optical Toroidal Microcavities

We study level crossing in the optical whispering-gallery (WG) modes by using toroidal microcavities. Experimentally, we image the stationary envelope patterns of the composite optical modes that arise when WG modes of different wavelengths coincide in frequency. Numerically, we calculate crossings of levels that correspond with the observed degenerate modes, where our method takes into account the not perfectly transverse nature of their field polarizations. In addition, we analyze anticrossing with a large avoidance gap between modes of the same azimuthal number

Origin of broad polydispersion in functionalized dendrimers and its effects on cancer cell binding affinity

Nanoparticles with multiple ligands have been proposed for use in nanomedicine. The multiple targeting ligands on each nanoparticle can bind to several locations on a cell surface facilitating both drug targeting and uptake. Experiments show that the distribution of conjugated ligands is unexpectedly broad, and the desorption rate appears to depends exponentially upon the mean number of attached ligands. These two findings are explained with a model in which ligands conjugate to the nanoparticle with a positive cooperativity of $\approx 4kT$, and that nanoparticles bound to a surface by multiple bonds are permanently affixed. This drives new analysis of the data, which confirms that there is only one time constant for desorption, that of a nanoparticle bound to the surface by a single bond.Comment: 4 pages, with 6 figure

PROPOSED ACCOUNTING STANDARD REQUIRES CAPITALIZATION OF ALL LONG-TERM LEASES FOR LESSEES

Accounting for leases has been a controversial issue both internationally and in the United States for a number of years. The focus of the issue has been whether or not simply disclosing the amount of lease commitments by the lessee in the notes to the financial statements is adequate financial reporting for long-term leases classified as operating leases. In 2010 the Financial Accounting Standards Board and International Accounting Standards Board jointly issued an exposure draft, Leases (Topic 840), requiring lessees to report an asset and liability for the present value of the committed lease payments or contracts that extend for more than one year. In July 2011, the two boards agreed to re-expose their proposal for this leases standard. A revised proposal was issued in May 2013. This paper examines changes in several balance sheet and income statement ratios by industry and specifically for a grocery store, a merchandiser, and an airline, that will result from the new accounting standard. As expected, ratios involving liabilities change in a direction making the companies appear more risky. In addition, the income statements are revised by imputing interest on the assumed capitalized amount of noncancellable leases and the interest coverage ratios are recalculated. Two companies reporting profits show a decline in the ratio while the airline actually experiences the ratio changing from negative to positive

Control analysis of the TMT primary segment assembly

The primary mirror control system (M1CS) stabilizes the 492 segments of the Thirty Meter Telescope primary mirror in the presence of disturbances. Each Primary Segment Assembly (PSA) has three actuators and position sensors that control the piston, tip, and tilt of the mirror segment. Requirements for the PSA position controller are presented, with the main requirements being 10 Newton per micron stiffness below one Hertz, where wind is the primary disturbance. Bandwidths of the PSA position controller of about twenty Hertz, assuming a soft actuator, are needed to meet this requirement. A finite element model of the PSA was developed and used for a preliminary control design. PSA structural modes at 40, 90, and 120 impact the control design. We have studied control designs with different actuators, sensors, and structural filters in order to assess disturbance rejection properties and interactions with the PSA structural modes. The performance requirements are achieved using voice coil actuators with modal control architecture for piston, tip, and tilt. Force interactions with the underlying mirror cell are important, and we present the status of our studies of the control structure interaction effect (CSIE). A related paper presents further analysis of the CSIE and MICS global position control loop

Analysis of the TMT mount control system

The TMT mount control system provides telescope pointing and tracking. Requirements include wind disturbance rejection, offsetting time and accuracy, control system robustness, and the magnitude of response at structural resonances. A finite element model of the complete telescope has been developed and the transfer functions used for the control designs are presented. Wind disturbance, encoder, and wave-front-sensor models are presented that are used for the control design. A performance analysis translates the requirements to a required bandwidth. Achieving this bandwidth is important for reducing telescope image motion due to wind-buffeting. A mount control design is presented that meets the demanding requirements by maximizing low frequency gain and using structural filters to roll-off structural modes. The control system analysis includes an outer guide loop using a wave front sensor. Offsetting time and accuracy requirements are satisfied using feed-forward control architecture

Extraordinary Item Classification Eliminated from the Income Statement: Some Supportive Evidence

Accounting Standards Update 2015-01 formally eliminated the reporting of extraordinary items in the income statement for fiscal years beginning after December 15, 2015. Gains and losses previously reported as extraordinary items and presented separately below income from continuing operations, are now reported as other gains and losses and included in income from continuing operations. The use of the extraordinary item classification fell sharply after 2002 when gains and losses from the early extinguishment of debt were no longer required to be reported as extraordinary items. By 2003 less than 100 publicly traded firms reported extraordinary items and in 2011 the number was only in the single digits. Finally, in 2013 and 2014 not a single firm in our sample, drawn from the Compustat database, reported an extraordinary item

Change in Reporting the Funded Status of Pensions: Impact on Debt-Asset and Debt-Equity Ratios

In September 2006, the Financial Accounting Standards Board issued a new standard for pensions, referred to when issued as Statement of Financial Accounting Standards No. 158 Employers\u27 Accounting for Defined Benefit Pension and Other Postretirement Plans (FASB 2006) and currently referred to as Accounting Standards Codification (ASC) 715 Compensation—Retirement Benefits, 30 Defined Benefit Plans—Pension, 25 Recognition. The objective of the new standard is to increase understandability of financial statements and improve timeliness and representational faithfulness relating to the funded status of defined benefit pension plans. The results presented in this study demonstrate the impact the new standard has on debt-asset ratios and on debt-equity ratios. Accordingly, the new accounting standard causes some firms to experience a material deterioration in their financial position based on the debt-asset and debt-equity ratios. The new standard provides a more conservative and accurate reporting of the funded status of defined benefit pension plans and therefore more useful information to investors and creditors