scholarly journals The first GPS-TEC imaging of the space structure of MS wave packets excited by the solar terminator

2009 ◽  
Vol 27 (4) ◽  
pp. 1521-1525 ◽  
Author(s):  
E. L. Afraimovich ◽  
I. K. Edemskiy ◽  
S. V. Voeykov ◽  
Yu. V. Yasyukevich ◽  
I. V. Zhivetiev
Keyword(s):  
Wave Packets ◽  
Wave Length ◽  
Space Structure ◽  
Time Shift ◽  
Long Distance ◽  
Gps Tec ◽  
Time Period ◽  
Solar Terminator ◽  
High Coherence ◽  
Space Image

Abstract. Using TEC measurements from the dense network of GPS sites GEONET, we have obtained the first GPS-TEC image of the space structure of medium-scale traveling wave packets (MS TWP) excited by the morning solar terminator (ST). We found that ST-generated wave packets have duration of about 1–2 h and time shift of about 1.5–6 h after the morning ST appearance at an altitude of 300 km. The TWP wave front extends along the morning ST line with the angular shift of about 20°. The time period and wave-length of ST-generated wave packets are about 10–20 min and 200–300 km, respectively. The velocity of the TWP phase front traveling is of about 300 m/s. The space image of MS TWP manifests itself in pronounced anisotropy and high coherence over a long distance of about 2000 km.

scholarly journals CONSTRAINTS EXPERIENCED BY MUSHROOM GROWERS IN ADOPTING IMPROVED MUSHROOM PRODUCTION PRACTICES IN PUSA, BIHAR

2021 ◽  
Vol 8 (7) ◽  
pp. 97-106
Author(s):  
Saloni Sarraf ◽  
Dipak Kumar Bose ◽  
Jahanara Jahanara ◽  
Amit Kumar
Keyword(s):  
Transport Cost ◽  
Primary Data ◽  
Mushroom Cultivation ◽  
Short Time Period ◽  
Long Distance ◽  
Mushroom Production ◽  
Time Period ◽  
Production Practices ◽  
Short Time ◽  
Technical Guidance

Mushrooms (vegetarian meat/vegetable beef stick) is becoming fast popular because of its short time period between cultivation and harvesting; less initial investment and can be grown with locally available resources. Though more technology is available for boosting mushroom production, the yield so far achieved is not high. Hence, an attempt is made to find out the constraints faced by mushroom growers in adoption of improved mushroom production practices. Samastipur district of Bihar was purposively selected for the study because, Dr. Rajendra Prasad Central Agricultural University, a pioneer in mushroom production technology is located in the study area. 120 respondents from six villages of Pusa, Samastipur, Bihar forms the respondents of the present study. Primary data was collected from the mushroom growers and the responses were subjected to statistical analysis. The results indicated that unavailability of quality spawn, unavailability of skilled labor, absence of technical guidance, high transport cost, unavailability of storage facilities, high cost of spawn and long distance market were the most problematic constraints faced by the mushroom growers. Thus, it can be concluded that adequate extension service should be made available to make mushroom cultivation popular, market and marketing of the products.

scholarly journals Propagation of wave-packets incident obliquely upon a stratified doubly refracting ionosphere

1938 ◽  
Vol 237 (781) ◽  
pp. 411-451 ◽  
Keyword(s):  
Electromagnetic Waves ◽  
Wave Packets ◽  
Wave Length ◽  
Oblique Propagation ◽  
Vertical Propagation ◽  
General Investigation

Little attempt has so far been made to apply Appleton’s magneto-ionic theory to wireless waves incident obliquely upon the ionosphere. Actually the magneto-ionic theory in the form given by Appleton (1925,1932) and others (Nichols and Schelleng 1925; Breit 1927; Goldstein 1928) is only suitable for investigating vertical propagation in the ionosphere, and it is the object of this communication to develop a generalization of Appleton’s magneto-ionic theory capable of dealing conveniently with waves incident obliquely upon the ionosphere. A general investigation into oblique propagation of electromagnetic waves through a slowly varying doubly refracting medium has already been made (Booker 1936), and the ideas there developed will now be applied to propagation through the ionosphere of wireless waves of wave-length sufficiently short (less than a kilometre, say) to regard the medium as slowly varying.

Travelling wave packets generated by the solar terminator in the upper atmosphere

2010 ◽  
Vol 23 (1) ◽  
pp. 21-27
Author(s):  
E. L. Afraimovich ◽  
I. K. Edemskiy ◽  
S. V. Voeykov ◽  
Yu. V. Yasyukevich ◽  
I. V. Zhivetiev
Keyword(s):  
Wave Packets ◽  
Travelling Wave ◽  
Upper Atmosphere ◽  
Solar Terminator

Solar terminator-related ionosphere derived from GPS TEC measurements: A case study

2011 ◽  
Vol 60 (4) ◽  
pp. 1224-1235 ◽  
Author(s):  
Marcin Grzesiak ◽  
Anna Świątek
Keyword(s):  
Gps Tec ◽  
Solar Terminator

The stability of viscous fluid flow between rotating cylinders

1937 ◽  
Vol 33 (1) ◽  
pp. 41-61 ◽  
Author(s):  
S. Goldstein
Keyword(s):  
Angular Velocity ◽  
Wave Length ◽  
Steady Motion ◽  
Circular Cylinders ◽  
Critical Flow ◽  
Average Value ◽  
Time Period ◽  
Component Velocity ◽  
The Stability ◽  
Image Position

The stability of the motion of viscous incompressible fluid, of density ρ and kinematic viscosity ν, between two infinitely long coaxial circular cylinders, of radiiaanda+d, whered/ais small, is investigated mathematically by the method of small oscillations. The inner cylinder is rotating with angular velocity ω and the outer one with angular velocity αω, and there is a constant pressure gradient parallel to the axis. The fluid therefore has a component velocityWparallel to the axis, in addition to the velocity round the axis. A disturbance is assumed which is symmetrical about the axis and periodic along it. The critical disturbance, which neither increases nor decreases with the time, is periodic with respect to the time (except whenW= 0, when the critical disturbance is a steady motion). As Reynolds number of the flow we take ||d/ν, whereis the average value ofWacross the annulus, and we denote bylthe wave-length of the disturbance along the axis, by σ/2π the time period of the critical flow, bycthe wavelength of the critical flow, byωcthe critical value of ω, and we putapproximately, if α is not nearly equal to 1.

Spatio-temporal structure of the wave packets generated by the solar terminator

2009 ◽  
Vol 44 (7) ◽  
pp. 824-835 ◽  
Author(s):  
E.L. Afraimovich ◽  
I.K. Edemskiy ◽  
S.V. Voeykov ◽  
Yu.V. Yasyukevich ◽  
I.V. Zhivetiev
Keyword(s):  
Wave Packets ◽  
Temporal Structure ◽  
Solar Terminator ◽  
Spatio Temporal

scholarly journals Observing wave packets generated by solar terminator in TEC during typhoons

2018 ◽  
Vol 4 (2) ◽  
pp. 33-40
Author(s):  
Илья Едемский ◽  
Ilya Edemsky ◽  
Анна Ясюкевич ◽  
Anna Yasyukevich
Keyword(s):  
Tropical Cyclones ◽  
Wave Packets ◽  
Maximum Amplitude ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Total Electron ◽  
The Pacific ◽  
Typhoon Center ◽  
The Pacific Ocean ◽  
Solar Terminator

In this work, we study ionospheric disturbances excited by the passage of the solar terminator (ST) during tropical cyclones, using total electron content (TEC) data. We have considered 16 intense tropical cyclones (typhoons) that acted in the northwest of the Pacific Ocean near the territory of Japan. We analyze two-dimensional distributions of the number of registered wave packets (WPs) depending on various parameters: local time, WP maximum amplitude, and distance to typhoon. It is shown that in most cases the maximum number of WPs is observed at a distance less than 500–1500 km from the typhoon center and near the time of evening solar terminator passage. For typhoons occurring during autumn periods, the maximum number of WPs is recorded at daytime, and, apparently, is not associated with ST. Distributions of the number of WPs depending on their amplitude have a similar form for all the cases considered, with a maximum of about 0.2 TECU. At the same time, for some typhoons there are a large number of WPs with amplitude up to 0.6–0.8 TECU, which is significantly higher than WP amplitudes under quiet conditions. We briefly discuss the mechanism of possible interaction between ionospheric disturbances caused by two different sources (tropical cyclones and ST passage).

scholarly journals LOCALLY OBTAINED WATERMELON TRANSPLANTS OUTPERFORM FLORIDA TRANSPLANTS IN ARKANSAS FIELD TRIALS

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1177f-1177
Author(s):  
Tina Gray Teague
Keyword(s):  
Field Trials ◽  
Plant Spacing ◽  
Cumulative Yield ◽  
Long Distance ◽  
Plot Size ◽  
Time Period ◽  
Square Cells ◽  
In Transit ◽  
Locally Grown ◽  
Comparable Quality

Four week old watermelon (cv. Royal Sweet) transplants were obtained from long distance (FL) and local (AR) commercial transplant growers and set in plots in a commercial watermelon field near Leachville AR. Transplants (plugs) from AR (Burton's Inc., Tupelo, AR) were grown in inverted pyramid, Todd Flats (model 100A; 5/8″ length X 1/2″ width X 3″ height) (Speedling Inc., Sun City, FL). FL transplants (LaBelle Plant World, LaBelle, FL) were grown in 1.5″ square cells, 2″ deep. All transplants were delivered 15 April and set on 16 April. Transit time for local transplants was < 2 hrs, and plants were delivered in original flats. FL transplants were shipped on 14 April and were in transit ca. 28 hrs. They had been pulled from trays and were shipped in cardboard boxes. Plot size was 6 beds, 53.3m long with treatments arranged in a RCB with 4 replications. Bed spacing was 2.9m with between plant spacing of 1.5m. Data were subjected to ANOVA with mean separation by LSD. Plots were harvested 3, 8, 15 and 22 July. Total number of fruit produced from plots planted with AR transplants was greater than FL treatment plots in the first 3 of 4 harvests; significantly higher total cumulative yield was observed with AR compared to FL transplants (45,115 and 35,172 kg ha-1, respectively). Increases in-yield and earliness resulted in an increase in gross profit of $1225 ha-1 for local transplants (based on national price data from that time period). No differences in average weights of fruit were observed for any harvests. Results indicate that Mid-South watermelon producers could benefit from utilizing locally grown transplants if plants are of comparable quality to those available from distant suppliers.

scholarly journals Molluscs of the Genus Glycymeris from Vogelherd Cave near Niederstotzingen (Lonetal, Southwestern Germany)

2021 ◽  
Vol 29 ◽  
Author(s):  
Benjamin Schuerch ◽  
Sibylle Wolf ◽  
Patrick Schmidt ◽  
Nicholas J. Conard
Keyword(s):  
Electron Microscope ◽  
Upper Paleolithic ◽  
Long Distance ◽  
Southern Germany ◽  
Mainz Basin ◽  
Time Period ◽  
Raster Electron Microscope ◽  
Wide Range ◽  
Lithic Artifacts ◽  
Best Fit

The site of Vogelherd in the Lone Valley of southwestern Germany has become world famous for its many unique artworks made from mammoth ivory, personal ornaments, flute fragments, lithic artifacts, and antler and bone artifacts. In the study below, the molluscs from Vogelherd are presented, offering us new insights on the mobility and social behavior of Aurignacian groups in the Lone Valley. Some of the mollusc finds come from the 1931 excavation of Gustav Riek; however, most of them were uncovered during the later re-excavations of the site between 2005 and 2012. In order to provide context for these finds, we compare the molluscs from Vogelherd with those from across Central Europe. The identifiable fragments from Vogelherd belong to the genus Glycymeris. The Glycymeris molluscs originated from the Mainz Basin. This determination makes it possible to reconstruct one of the farthest long-distance connections known for the Upper Paleolithic in Germany. In addition to the Glycymeris finds, we present a tool that was also made from a mollusc. This mollusc-tool, coming from the excavation of 1931 and attributed to the Aurignacian, is a unique find for this time period of southern Germany. With this piece, along with microscopic examinations and discussions of the Glycymeris molluscs, we present a wide range of possible uses for these finds. For example, we discuss the possible use of the molluscs as ochre containers. To test this, we used EDX-analysis and a raster electron microscope. We compare the Glycymeris molluscs of Vogelherd with those from Gravettian and Magdalenian contexts at Hohle Fels, Geißenklösterle, Petersfels, and Gnirshöhle, and we provide a list of all sites from Germany, Switzerland, Eastern France, and Belgium with Glycymeris finds. We use size comparisons to show differences as well among the Glycymeris finds of Vogelherd and other Upper Paleolithic sites in southwestern Germany. In conclusion, we demonstrate that the Glycymeris molluscs of Vogelherd best fit into the Aurignacian, and we provide other Aurignacian sites that contained similar finds. By discussing other long-distance connections in the Aurignacian of southern Germany, it becomes evident that Glycymeris molluscs are not specific only to the Swabian Aurignacian.

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