1,163 research outputs found
Remote sensing of cloud distribution
Day and night mapping of the global distribution of the horizontal cloud-cover and the corresponding cloud-top pressure levels can be derived from the same infrared data used to derive clear column temperature profiles. Applications to the 15 micrometer VTPR data are given. Extension of this approach for the determination of the radiative transfer properties of clouds is presented and the possibility of using such information to infer cloud types is discussed
Structure of a Plane Shock Layer
The structure of a plane shock wave is discussed and the expected range of applicability of the NavierâStokes equations within the shock layer is outlined. The shock profiles are computed using the BhatnagarâGrossâKrook model of the Boltzmann equation and a uniformly converging iteration scheme starting from the NavierâStokes solution. It is shown that the NavierâStokes solution remains a good approximation in the highâpressure region of the shock layer up to approximately the point of maximum stress for all shock strengths. In the lowâpressure region, the correct profiles deviate with increasing shock strength from the NavierâStokes solution. The physical significance of the kinetic model used and the relation of the present study to previous theoretical and experimental work is discussed
Theoretical and Experimental Aspects of the Shock Structure Problem
Flow of rarefied gases - Shock wave structure proble
The Blackhole-Dark Matter Halo Connection
We explore the connection between the central supermassive blackholes (SMBH)
in galaxies and the dark matter halo through the relation between the masses of
the SMBHs and the maximum circular velocities of the host galaxies, as well as
the relationship between stellar velocity dispersion of the spheroidal
component and the circular velocity. Our assumption here is that the circular
velocity is a proxy for the mass of the dark matter halo. We rely on a
heterogeneous sample containing galaxies of all types. The only requirement is
that the galaxy has a direct measurement of the mass of its SMBH and a direct
measurement of its circular velocity and its velocity dispersion. Previous
studies have analyzed the connection between the SMBH and dark matter halo
through the relationship between the circular velocity and the bulge velocity
dispersion, with the assumption that the bulge velocity dispersion stands in
for the mass of the SMBH, via the well{}-established SMBH mass{}-bulge velocity
dispersion relation. Using intermediate relations may be misleading when one is
studying them to decipher the active ingredients of galaxy formation and
evolution. We believe that our approach will provide a more direct probe of the
SMBH and the dark matter halo connection. We find that the correlation between
the mass of supermassive blackholes and the circular velocities of the host
galaxies is extremely weak, leading us to state the dark matter halo may not
play a major role in regulating the blackhole growth in the present Universe.Comment: Accepted for publication in the Ap
The GLAS physical inversion method for analysis of HIRS2/MSU sounding data
Goddard Laboratory for Atmospheric Sciences has developed a method to derive atmospheric temperature profiles, sea or land surface temperatures, sea ice extent and snow cover, and cloud heights and fractional cloud, from HIRS2/MSU radiance data. Chapter 1 describes the physics used in the radiative transfer calculations and demonstrates the accuracy of the calculations. Chapter 2 describes the rapid transmittance algorithm used and demonstrates its accuracy. Chapter 3 describes the theory and application of the techniques used to analyze the satellite data. Chapter 4 shows results obtained for January 1979
Investigations carried out under the Director's Discretionary Fund
This annual report comprises a set of summaries, describing task objectives, progress and results or accomplishments, future outlook, and financial status for each director's discretionary fund (DDF) task that was active during fiscal year 1984. Publications and conference presentations related to the work are listed. The individual reports are categorized as interim or final according to whether the task efforts are ongoing or completed. A partial list of new tasks to be initiated with fiscal year 1985 funds and a glossary of abbreviations and acronyms, used by the task authors in their summaries are included. The table of contents lists the DDF reports in sequence by their task number, which is derived from the 13-digit code assigned to account for the fund awarded to the task project
Collaborative Evaluative Inquiry: A Model for Improving Mathematics Instruction in Urban Elementary Schools
In this article, the authors describe the cyclical process of a collaborative evaluative inquiry project and the data collected throughout the projectâdata that not only informed next steps during the project but also show promise in documenting the benefits of such projects. Over a period of 18 months, seven elementary teachers from a Kâ6 urban elementary school collaborated with university personnel using Parsonsâs (2002) Evaluative Inquiry Model, a 5-stage, cyclical model that includes defining, planning, and investigating challenges; collecting, analyzing, and synthesizing data; and communicating findings that transpire through collaborative inquiry. Overall, the project focused on improving the elementary teachersâ skills of inquiry and, in turn, their mathematics instruction and studentsâ learning outcomes. The long-term goal was to enhance teachersâ roles in their schools by affording them the opportunities to make informed decisions throughout their teaching based on an effective and skillful use of data
The relationship between public listing, context, multi-nationality and internal CSR
Are MNEs more socially responsible, and where is this more likely to occur? Are firms less responsible in emerging or transitional economies, and what impact does the dominant national corporate governance regime have? We explore the association between public listing and the existence of a CSR code within specific institutional settings and assess whether MNEs are any different to their local counterparts, based on an internationally comparative survey. We find that listed firms as well as firms from civil law countries are more likely to have CSR statements. MNEs are also more likely to have CSR statement, independent of their country of origin. While we find consistent evidence of a correlation between the existence of a CSR statement and investment in staff training, the correlation between the former and employee-friendly HRM is weaker
Posterior wiring with sublaminar polyester bands, titanium-peek fixation system for C2 fracture management: a 4-patient case series with a maximum of 18 monthsâ follow-up
Background: C2 fractures can be classified differently when dens, pedicles or body are injured. With regards to the best management of Type-II Anderson-DâAlonzo fractures, Hangmanâs fractures of pedicles and C2 body fractures are more debatable. However, vertebral pedicle and/or articular screw and dorsal wiring are the most common surgical posterior approaches opted for. Compared to the screw technique, dorsal wiring provides certain benefits such as a lower risk of vertebral artery injury, no need for navigation, less lateral dissection of the paraspinal muscles, shorter surgery time and lower medical costs. Case Description: Two patients with failed conservative treatment for Anderson-DâAlonzo Type-III fractures (Cases 1A and 1B), a patient suffering from a Type-II Hangmanâs fracture (Case 2) and a patient with failed conservative treatment for a C2 transversal body fracture (Case 3) underwent surgery at the Neurosurgery Division of the University Hospital of Modena (Italy) between July 2020 and September 2021. All patients were treated with posterior wiring with 5 mm Polyester bands, titanium-peek fixation system (Jazz-Lock system MediNextÂź-Implanet) inserted through the C1 posterior arch and either the C2 or C3 laminae. A fracture diastasis reduction was observed ranging between 4.5 and 1 mm. No intraoperative and post-operative complications were encountered. The duration of the period of hospitalisation ranged between 5 and 12 days. All patients who had worked prior to the traumatic event were able to return to work 18 months following surgery. Conclusions: In reducing C2 fractures, a sublaminar fixation with polyester bands and a titanium-peek fixation system can be proposed for fragile and elderly patients
- âŠ