3,307 research outputs found
Detection of Non-Random Galaxy Orientations in X-ray Subclusters of the Coma Cluster
This study on the Coma cluster suggests that there are deviations from a
completely random galaxy orientation on small scales. Since we found a
significant coincidence of hot-gas features identified in the latest X-ray
observations of Coma with these local anisotropies, they may indicate regions
of recent mutual interaction of member galaxies within subclusters which are
currently falling in on the main cluster.Comment: 4 pages, 4 figures, 3 tables v2: Rewritten introduction, amendments
to the 'Interpretation' sectio
An investigation into the fertilizer particle dynamics off-the-disc
The particle size range specifications for two biosolids-derived organomineral fertilizers (OMF) known as OMF10 (10:4:4) and OMF15 (15:4:4) were established. Such specifications will enable field application of OMF with spinning disc systems using conventional tramlines spacing. A theoretical model was developed, which predicts the trajectory of individual fertilizer particles off-the-disc. The drag coefficient (Cd) was estimated for small time steps (10-6 s) in the trajectory of the particle as a function of the Reynolds number. For the range of initial velocities (20 to 40 m s-1), release angles (0Ă° to 10Ă°) and particle densities (1000 to 2000 kg m-3) investigated, the analysis showed that OMF10 and OMF15 need to have particle diameters between 1.10 and 5.80 mm, and between 1.05 and 5.50 mm, respectively, to provide similar spreading performance to urea with particle size range of 1.00 to 5.25 mm in diameter. OMF10 and OMF15 should have 80% (by weight) of particles between 2.65 and 4.30 mm, and between 2.55 and 4.10 mm, respectively. Due to the physical properties of the material, disc designs and settings that enable working at a specified bout width by providing a small upward particle trajectory angle (e.g., 10Ă°) are preferred to high rotational velocities. However, field application of OMF with spinning discs applicators may be restricted to tramlines spaced at a maximum of 24 m; particularly, when some degree of overlapping is required between two adjacent bouts. The performance of granular fertilizers can be predicted based on properties of the material, such as particle density and size range, using the contour plots developed in this study
An Economic analysis of the potential for precision farming in UK cereal production
The results from alternative spatial nitrogen application studies are analysed in economic terms and compared to the costs of precision farming hardware, software and other services for cereal crops in the UK. At current prices, the benefits of variable rate application of nitrogen exceed the returns from a uniform application by an average of ÂŁ22 haâ1 The cost of the precision farming systems range from ÂŁ5 to ÂŁ18 haâ1 depending upon the system chosen for an area of 250 ha. The benefits outweigh the associated costs for cereal farms in excess of 80 ha for the lowest price system to 200â300 ha for the more sophisticated systems. The scale of benefits obtained depends upon the magnitude of the response to the treatment and the proportion of the field that will respond. To be cost effective, a farmed area of 250 ha of cereals, where 30% of the area will respond to variable treatment, requires an increase in crop yield in the responsive areas of between 0·25 and 1.00 t haâ1 (at ÂŁ65 tâ1) for the basic and most expensive precision farming systems, respectively
Report on holographic tests at S-band and K-band on the DSS-63 64 metre antenna
High resolution holographic tests were carried out on DSS-63 at S-band and K-band during May l985. These tests followed a mechanical retrofit which involved the addition of structural bracing to the backing structure. Geosynchronous satellite beacons were used as sources for the tests. At a resolution of 0.4m the S-band and K-band tests revealed rms deviations of the surface to be 2.73mm and 1.53mm, respectively. The difference between these two results is thought to be due mainly to contamination of the S-band surface error map by expected and generally predictable subreflector diffraction effects. The S-band map is also known to be contaminated by diffraction from the subreflector support struts and has a higher noise level than the K-band map. A list of corrections to be applied to the reflector panels is derived from the K-band map. These corrections are predicted to reduce the rms deviation from 1.53mm to 0.86mm at 0.4m resolution. Comparison with results obtained before the mechanical retrofit suggests the major effect of the added structural bracing to be reduction of a third order deformation of the reflector about its axis
Seedling Performance Associated with Live or Herbicide Treated Tall Fescue
Tall fescue is an important forage grass which can host systemic fungal endophytes. The association of host grass and endophyte is known to influence herbivore behavior and host plant competition for resources. Establishing legumes into existing tall fescue sods is a desirable means to acquire nitrogen and enhance the nutritive value of forage for livestock production. Competition from existing tall fescue typically must be controlled to ensure interseeding success. We used a soil-on-agar method to determine if soil from intact, living (L), or an herbicide killed (K) tall fescue sward influenced germination and seedling growth of three cultivars of tall fescue (E+, MaxQ, and Eâ) or legumes (alfalfa, red clover, and white clover). After 30 days, seedlings were larger and present in greater numbers when grown in L soil rather than K soil. Root growth of legumes (especially white clover) and tall fescue (especially MaxQ) were not as vigorous in K soil as L soil. While shoot biomass was similar for all cultivars of tall fescue in L soil, MaxQ produced less herbage when grown in K soil. Our data suggest establishing legumes or fescue cultivars may not be improved by first killing the existing fescue sod and seedling performance can exhibit significant interseasonal variation, related only to soil conditions
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Simulations of laser thrombolysis
The authors have shown that bubble expansion and collapse near the interface between two materials with modest property differences produces jet-like interpenetration of the two materials. The bubble dynamics at a water-viscous fluid interface is compared with that at the interface of water with a weak elastic-plastic material. The authors find that, despite rather similar behavior during bubble growth and the initial portion of bubble collapse, the terminal jetting behavior is quite different, even in direction. The elastic-plastic properties chosen realistically represent real and surrogate thrombus. Simulations using the elastic-plastic model quantitatively agree with laboratory thrombolysis mass removal experiments. In the earlier simulations of laboratory experiments, walls have been remote so as to not effect the dynamics. Here the authors present two-dimensional simulations of thrombolysis with water over elastic-plastic surrogate thrombus in a geometry representative of the clinical situation. The calculations include thin cylindrical elastic walls with properties and dimensions appropriate for arteries. The presence of these artery walls does not substantially change the interface jetting predicted in unconfined simulations
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Gender differences in use and preferences of agricultural information sources in Pakistan
Purpose: Rural advisory services ensure agricultural information is
disseminated to rural populations, yet they are less accessible to
women. This research provides insight on gender differences in
information access by investigating frequency of use and
preference of agricultural information sources by gender in a rural
setting, differentiated according to literacy and age.
Design/Methodology/approach: This study interviewed 401
male/female individuals in farm households in Jhang and
Bahawalpur district of Punjab, Pakistan in 2016.
Findings: Men and women farmersâ use and preferences in
accessing information sources are extremely different. Women
hardly use sources for agricultural information, and value
interpersonal communication from informal sources. In contrast,
men use and value official agencies more. Radio, surprisingly, was
very rarely used, contradicting previous findings of research
elsewhere. Age and literacy affect differences between women
more than it does between men, particularly for convenient
locations to access information. Practical implications The study
identified and refined major gender differences regarding use and
preference for agricultural information in relation to age and
literacy, and helps to articulate options to improve gender
equality of access to agricultural information in Pakistan.
Theoretical implications: The focus and outcomes regarding
gender intersecting with age and literacy in agricultural
information access imply the need for more refined socioeconomic
models, discerning and interrelating gender and other
social dimensions beyond the standard of male-headed households.
Originality/value: This paper adds to the growing body of evidence
on information access according to gender, highlighting the need to
investigate deeper socio-cultural issues around age and literacy
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Physical mechanisms of importance to laser thrombolysis
Bubble dynamics plays a key role in many medical procedures including Laser Thrombolysis (L-T), acoustic and laser lithotripsy, interocular laser surgery, photoacoustic drug delivery, and perhaps ultrasonic imaging. The authors are investigating the effect that interfaces of different materials, especially biological and biomedical materials, have on the dynamics of nearby bubbles. Collapsing bubbles often become nonspherical, resulting in spectacular directed motion with potentially both beneficial and undesirable consequences. This directed motion may explain L-T mass removal and some types of laser-induced tissue damage
Three operational taxonomic units of Eimeria are common in Nigerian chickens and may undermine effective diagnosis of coccidiosis
Support Vector Machine based Image Classification for Deaf and Mute People
A hand gesture recognition system provides a natural, innovative and modern way of nonverbal communication. It has a wide area of application in human computer interaction and sign language. The whole system consists of three components: hand detection, gesture recognition and human-computer interaction (HCI) based on recognition; in the existing technique, ANFIS(adaptive neuro-fuzzy interface system) to recognize gestures and makes it attainable to identify relatively complex gestures were used. But the complexity is high and performance is low. To achieve high accuracy and high performance with less complexity, a gray illumination technique is introduced in the proposed Hand gesture recognition. Here, live video is converted into frames and resize the frame, then apply gray illumination algorithm for color balancing in order to separate the skin separately. Then morphological feature extraction operation is carried out. After that support vector machine (SVM) train and testing process are carried out for gesture recognition. Finally, the character sound is played as audio output
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