scholarly journals A Study of "Spread?F" Ionospheric Echoes at Night at Brisbane. III. Frequency Spreading

1957 ◽  
Vol 10 (1) ◽  
pp. 60 ◽  
Author(s):  
DG Singleton
Keyword(s):  
Fine Structure ◽  
World Wide ◽  
Recent Literature ◽  
Temporal Analysis ◽  
Seasonal Distribution ◽  
The World ◽  
Diurnal Distribution ◽  
The Hours ◽  
Spread F ◽  
Pronounced Peak

Virtual range versus frequency (P'f) records of the ionosphere made at Brisbane (lat. 27�5 �S., long. 152�9 �E.) during 1952 and 1953 have been examined. It is found that occasionally neither the o nor the x mode of propagation penetrates the F2 layer at a unique frequency, the upward sweeping traces either being blurred out over a range of penetration frequencies (diffuseness) or possessing a fine structure (penetration-frequency multiplicity). Temporal analysis of the occurrence of these. effects reveals that they occur only at night; penetration-frequency multiplicity appearing more frequently in the hours before dawn, while the diurnal distribution of diffuseness has a maximum between 0100 and 0500 hr in summer and represents a more even distribution between 2100 and 0500 hr in winter. The seasonal distribution has a pronounced peak in the winter months and minima in the equinoctial months. These data are compared with the world-wide picture of these variations as it has emerged from the recent literature.

Rotational Characteristics of the Green Solar Corona: 1947-1991

1994 ◽  
Vol 144 ◽  
pp. 139-141 ◽  
Author(s):  
J. Rybák ◽  
V. Rušin ◽  
M. Rybanský
Keyword(s):  
Solar Corona ◽  
World Wide ◽  
Rotation Period ◽  
Original Data ◽  
Coronal Emission ◽  
Time Intervals ◽  
Data Set ◽  
The World ◽  
Coronal Emission Line ◽  
Homogeneous Data

AbstractFe XIV 530.3 nm coronal emission line observations have been used for the estimation of the green solar corona rotation. A homogeneous data set, created from measurements of the world-wide coronagraphic network, has been examined with a help of correlation analysis to reveal the averaged synodic rotation period as a function of latitude and time over the epoch from 1947 to 1991.The values of the synodic rotation period obtained for this epoch for the whole range of latitudes and a latitude band ±30° are 27.52±0.12 days and 26.95±0.21 days, resp. A differential rotation of green solar corona, with local period maxima around ±60° and minimum of the rotation period at the equator, was confirmed. No clear cyclic variation of the rotation has been found for examinated epoch but some monotonic trends for some time intervals are presented.A detailed investigation of the original data and their correlation functions has shown that an existence of sufficiently reliable tracers is not evident for the whole set of examinated data. This should be taken into account in future more precise estimations of the green corona rotation period.

Dancing Across the World Wide Web: Advocacy in the 21st Century

2009 ◽  
Author(s):  
Blair Williams Cronin ◽  
Ty Tedmon-Jones ◽  
Lora Wilson Mau
Keyword(s):  
World Wide Web ◽  
21St Century ◽  
World Wide ◽  
The World

Biodiesel production from non-edible oils: A review

2020 ◽  
pp. 149-159
Author(s):  
Jatinder Kataria ◽  
Saroj Kumar Mohapatra ◽  
Amit Pal
Keyword(s):  
Environmental Impact ◽  
Energy Demand ◽  
Fossil Fuels ◽  
World Wide ◽  
Edible Oils ◽  
Control Measure ◽  
Biodiesel Production ◽  
Pollution Level ◽  
Animal Fats ◽  
The World

The limited fossil reserves, spiraling price and environmental impact due to usage of fossil fuels leads the world wide researchers’ interest in using alternative renewable and environment safe fuels that can meet the energy demand. Biodiesel is an emerging renewable alternative fuel to conventional diesel which can be produced from both edible and non-edible oils, animal fats, algae etc. The society is in dire need of using renewable fuels as an immediate control measure to mitigate the pollution level. In this work an attempt is made to review the requisite and access the capability of the biodiesel in improving the environmental degradation.

THE EUROPEAN UNION FORUM ON KIDS' SAFETY IN INTERNET SIF 2019

2019 ◽  
pp. 3-6
Author(s):  
D. A. Bogdanova
Keyword(s):  
European Union ◽  
World Wide Web ◽  
World Wide ◽  
The European Union ◽  
Internet Forum ◽  
The World

The article provides an overview of the activities of the European Union Forum on kids' safety in Internet — Safer Internet Forum (SIF) 2019, which was held in Brussels, Belgium, in November 2019. The current Internet risks addressed by the World Wide Web users, especially children, are described.

Profilometry. Using Corneo-scleral topography for scleral lens fitting

The Eye ◽  
2019 ◽  
Vol 21 (128) ◽  
pp. 19-22
Author(s):  
Gregory DeNaeyer
Keyword(s):  
Ocular Surface ◽  
World Wide ◽  
Contact Lenses ◽  
The Past ◽  
The World ◽  
The Future ◽  
The Way

The world-wide use of scleral contact lenses has dramatically increased over the past 10 year and has changed the way that we manage patients with corneal irregularity. Successfully fitting them can be challenging especially for eyes that have significant asymmetries of the cornea or sclera. The future of scleral lens fitting is utilizing corneo-scleral topography to accurately measure the anterior ocular surface and then using software to design lenses that identically match the scleral surface and evenly vault the cornea. This process allows the practitioner to efficiently fit a customized scleral lens that successfully provides the patient with comfortable wear and improved vision.

Sign in / Sign up

Export Citation Format

Share Document