Three dimensional steady and unsteady asymmetric flow past wings of arbitrary planforms

The nonlinear discrete vortex method was extended to treat the problem of asymmetric flows past a wing with leading-edge separation, including steady and unsteady flows. The problem was formulated in terms of a body-fixed frame of reference, and the nonlinear discrete vortex method was modified accordingly. Only examples of flows past delta wings are presented. Comparison of these results with experimental results for a delta wing undergoing a steady rolling motion at zero angle of attack demonstrates the superiority of the present method in obtaining highly accurate loads. Numerical results for yawed wings at large angles of attack are also presented. In all cases, total load coefficients, pressure distributions and shapes of the free-vortex sheets are shown

Unsteady flow past wings having sharp-edge separation

A vortex-lattice technique is developed to model unsteady, incompressible flow past thin wings. This technique predicts the shape of the wake as a function of time; thus, it is not restricted by planform, aspect ratio, or angle of attack as long as vortex bursting does not occur and the flow does not separate from the wing surface. Moreover, the technique can be applied to wings of arbitrary curvature undergoing general motion; thus, it can treat rigid-body motion, arbitrary wing deformation, gusts in the freestream, and periodic motions. Numerical results are presented for low-aspect rectangular wings undergoing a constant-rate, rigid-body rotation about the trailing edge. The results for the unsteady motion are compared with those predicted by assuming quasi-steady motion. The present results exhibit hysteretic behavior

Fuzzy Soft Connected Sets in Fuzzy Soft Topological Spaces

In this paper we introduce some types of fuzzy soft separated sets and study some of thier preperties. Next, the notion of connectedness in fuzzy topological spaces due to Ming and Ming, Zheng etc., extended to fuzzy soft topological spaces. The relationship between these types of connectedness in fuzzy soft topological spaces is investigated with the help of number of counter examples

Leucaena forage yield as influenced by soil conditioner and irrigation regime treatments

Water is limiting factor of increasing cultivated lands, so water scarcity and drought stress, considered as one of the factors limiting agricultural forage production in the world. This can have achieved by increasing of cultivated pasture area or improving productivity of rangeland plants. Soil conditioners applied in these holes during cultivation and vigorous seedlings transported to this experimental site. Unvarying daily irrigation using a drip irrigation system. Applying poultry manure as soil conditioners in sandy soil twisted tallest shrubs, maximum values of a number of branches/plant, stem thickness and dry matter forage yield per plant and per hectare and uppermost values of water use efficiency at both summer and autumn cuts. Increasing drip irrigation discharges from 2, 4, 6 to 8 litres/h significantly produced the tallest plants, highest number of branches per plant, thickness of stem and dry forage yield/plant and per hectare as well as water use efficiency in both summer and autumn cuts. As regards to the interaction between soil conditioners and drip irrigation discharges on stem height, number of branches /plant, dry forage matter yield per plant and dry forage yield/ha. Applying poultry manure as soil conditioners in sandy soil and increasing discharges of drip irrigation by 8 litres/h significantly increased dry forage yield/ha

Germination Characters as Affected by Salinity Stress and Soaking Grain Sorghum Genotypesin Humic acid

In order to investigate salinity stress on sorghum germination indices, an experiment conducted in the Faculty of Agriculture, Mansoura University from June and July 2017 in Agronomy Department, Seed Science Laboratory. The goals of the investigation aimed to screening for five (Sorghum bicolor L.(Moench) cultivarsviz. Dorado, hybrid 306, Giza 15, Mecca hybrid and H-305 under salinity stress, sodium chloride (Na Cl) at the levels of 0 (as control), 3, 6, 9, 12 and 15 dS/m-1 and soaking in humic acid. The results showed that soaking seed in humic acid exceeded percentage of germination, germination rate, germination index, energy of germination and chlorophyll content by 5.2, 7.7, 17.1, 65.8 and 17.8 %, respectively. The highest germination percentage (91.9 %), germination rate (3.08), germination energy (59.7), seedling vigor index (1483.7) and chlorophyll content (2.88) were obtained from sown Mecca hybrid. The maximum germination index (117.22) was obtainedfrom sown Giza 15 cultivar.The results point out that cumulative salinity level from 3 to 15 dSm-1condensedall studied germination characters. Accumulative salinity levels to 15 dSm-1condensedpercentage of germination, germination rate, index of germination, germination energy and seedling vigor index by 15.9, 15.0, 30.0, 35.9 and 37.6 %, respectively compared without salinity application. It could recommended that soaking sorghum seed of Meeca hybrid with humic acid for 12 h under salinity of concentration of 6 dSm-1 enhanced germination characters compared with other cultivars and salinity concentrations, it mean cultivated it under reclaimed saline soil in Egypt

Seedling Parameters as affected by Soaking in Humic Acid, Salinity Stress and Grain Sorghum Genotypes

To study the effect soaking in humic acid and salinity stress on sorghum seedling parameters, a laboratory experiment accompanied in Seed Science Laboratory Faculty of Agriculture Mansoura University from June 2017 to July 2017. This exploration intended to study performance of seedling parameters of five grain sorghum cultivars viz. Dorado, hybrid 306, Giza 15, Mecca hybrid and H-305 to soaking in humic acid under salinity concentrations of 3, 6, 9, 12 and 15 dS/m-1beside the control, and humic acid soaking. The results showed that seed soaking in humic acid recorded the tallest shoot and root, weight of fresh shoot and root, weight of dry shoot and the lowest percentages of relative dry weight and highest salinity tolerance index. Seed soaking in humic acid exceeded shoot and root length (cm), weight of fresh shoot and root, weight of dry shoot and tolerance index by 14.3, 92.6, 8.7, 4.5, 4.7 and 40.8%, respectively compared without soakingin humic acid.The tallest shoot and the fresh shoot weight were produced from germinating Giza 15 cultivar. In addition, the tallest roots and highest values of stress tolerance index were recorded from sown Mecca hybrid and Giza 15 cultivars without significant differences. It could be stated that sown Mecca hybrid surpassed H-305 cultivar in root length by 36.3 %. Moreover, Giza 15 cultivar surpassed H-305 in shoot length, shoot fresh weight and stress tolerance index by 30.6, 10.1 and 29.1 %, respectively. The results clearly revealed that accumulative salinity concentrations from 3, 6, 9, 12 and 15 dSm-1 significantly produced the shortest shoot, root, weight of fresh shoot, root, weight of dry shoot, and root, highest percentages of seedling height reduction, and stress tolerance index, except the percentage of relative dry weight increased with salinity levels increased. The shortest shoot and root (cm), were recorded from the highest salinity concentrations of 15 dSm-1. The gradually increases in salinity till of 15 dSm-1 significantly diminished the length of shoot and root, the fresh weight of shoot and root, the dry weight of shoot and root, seedling height reduction percentages, and stress tolerance index by 51.7, 17.7,4.7, 59.5, 38.7 and 57.4, respectively compared the control treatment. Accordingly, sown Mecca hybrid or Giza 15 cultivar with soaking in humic acid under salinity of 6 dSm-1maximized seedling parameters and could recommended to cultivated in saline new reclaimed soils

An Aeroelastic Analysis of a Thin Flexible Membrane

Studies have shown that significant vehicle mass and cost savings are possible with the use of ballutes for aero-capture. Through NASA's In-Space Propulsion program, a preliminary examination of ballute sensitivity to geometry and Reynolds number was conducted, and a single-pass coupling between an aero code and a finite element solver was used to assess the static aeroelastic effects. There remain, however, a variety of open questions regarding the dynamic aeroelastic stability of membrane structures for aero-capture, with the primary challenge being the prediction of the membrane flutter onset. The purpose of this paper is to describe and begin addressing these issues. The paper includes a review of the literature associated with the structural analysis of membranes and membrane utter. Flow/structure analysis coupling and hypersonic flow solver options are also discussed. An approach is proposed for tackling this problem that starts with a relatively simple geometry and develops and evaluates analysis methods and procedures. This preliminary study considers a computationally manageable 2-dimensional problem. The membrane structural models used in the paper include a nonlinear finite-difference model for static and dynamic analysis and a NASTRAN finite element membrane model for nonlinear static and linear normal modes analysis. Both structural models are coupled with a structured compressible flow solver for static aeroelastic analysis. For dynamic aeroelastic analyses, the NASTRAN normal modes are used in the structured compressible flow solver and 3rd order piston theories were used with the finite difference membrane model to simulate utter onset. Results from the various static and dynamic aeroelastic analyses are compared

Response of Some Sunflower Hybrids (Helianthus annuus l.) to Different Nitrogen Fertilizer Rates and Plant Densities

In order to improve sunflower productivity, this investigation aimed to study the performance of some genotypes to different doses of nitrogen and plant population density on seed yield and yield components. Two field Experiments carried out on the Experimental Farm of the Sakha Agriculture Research Station during 2015 and 2016 seasons. The objective of this study aimed to investigate the performance of some sunflower hybrids to different nitrogen fertilizer rates and plant population densities to growth, yield components, seed yield and its quality.The results indicated that tallest plants, highest leaves number/plant, number of achenes/head and highest values of head diameter were obtained from MS.sirena F1 genotype. Biest Brima genotype recorded the highest values of leaf area. The highest weight of 1000 seed and seed yield/ha were recorded from Nsovak genotype.The increases in nitrogen fertilizer rates to 168 Kg N/ha produced tallest plants,thick stems (cm), the highest leaves number/plant, leaf area (cm2), number of achenes/head, head diameter (cm), 1000 achene weight (gm) and achene yield (Kg/ha) in both seasons. It could observed that increasing nitrogen fertilizer from 72 to 168 Kg N/ha significantly increased seed yield by 12.0 and 11.6 % in the first and second seasons, respectively. Increasing hill spacing from 15, 20 and 25 cm produced thickness stem, highest number of leaves/plant, highest values of leaf area, maximum number of achenes/head, head diameter and weight of 1000 achene. The tallest plants and highest and achene yield were produced from 20cm hill spacing. It could concluded that increasing nitrogen fertilizer from 72 to 168 Kg N/ha and sown Nsovak genotype at dense hill spacing of 15 cm between plants maximized seed yield per unite area