Taking into account the significance of food chains in the environment, it demonstrates the interdependence of all living things and has economic implications for people. Hunting cooperation, fear, and intraspecific competition are all included in a food chain model that has been developed and researched. The study tries to comprehend how these elements affect the behavior of species along the food chain. We first examined the suggested model's solution properties before calculating every potential equilibrium point and examining the stability and bifurcation nearby. We have identified the factors that guarantee the global stability of the positive equilibrium point using the geometric approach. Additionally, the circumstances that would guarantee the continued existence of all living beings were computed. The theoretical findings were supported by numerical simulations, which also showed how altering parameter values affected the food chain's dynamic behavior.
Adsorption of o-Nitrophenol (o-Nph), m- Nitrophenol (m-Nph) and p- Nitrophenol (pNph) on the sedimentary sand of the Tigress River which is known locally by “Zemeej†from aqueous solution at 288, 298, 308, 318 and 328 k0 . This study indicates that o-Nph and mNph take multi-layered S type according to Giles classification while p-Nph takes a multilayered L type according to the same classification. The isotherms treated by Freundlich model and show a good response to this model because the heterogeneous nature of the surface. The adsorption for all materials was endothermic as shown from ΔH values and explained through the porous nature of the surface, the remaining thermodynamic functions ΔG and ΔS w
... Show MoreFlame thermal spray technique has been used to produce a cermets composite coating based on powders of ceramic oxides (
AhOJ) reinforced by mineral powders as bonding material ( Ni - AI ) at different rates on Inconel substrates , after preparing it by grit blasting.
After completing the best parameters of coating such as distance of spraying , surface roughness and angle of spraying , the tests of porosity , hardness , microstructure and thermal cycling have been made.
The experimental results show that all properties of coating were effected after heat treatment. The best value of heat treatmen t is at (I 000°C) for (l.Shr) in which the &
... Show MoreThe aim of this research is to develop qualitative workouts based on certain sensory perceptions for the development of offensive basketball abilities and to determine their impact on female pupils. Several findings, based on the au-thor's extensive expertise instructing basketball materials and our closeness to the sample, revealed deficits in some sensory perceptions “in the game of basketball”, which impair the accuracy of passing the ball to the best team-mate. It also affects the pace of dribbling and the difficulty of selecting the op-timal moment and distance to fire. Therefore, the researcher designs qualita-tive activities based on many sensory experiences, including distance, speed, force, and direction shift. In addition, the
... Show Moreفي هذا البحث نحاول تسليط الضوء على إحدى طرائق تقدير المعلمات الهيكلية لنماذج المعادلات الآنية الخطية والتي تزودنا بتقديرات متسقة تختلف أحيانا عن تلك التي نحصل عليها من أساليب الطرائق التقليدية الأخرى وفق الصيغة العامة لمقدرات K-CLASS. وهذه الطريقة تعرف بطريقة الإمكان الأعظم محدودة المعلومات "LIML" أو طريقة نسبة التباين الصغرى"LVR
... Show MoreIn this research, annealed nanostructured ZnO catalyst water putrefaction system was built using sun light and different wavelength lasers as stimulating light sources to enhance photocatalytic degradation activity of methylene blue (MB) dye as a model based on interfacial charges transfer. The structural, crystallite size, morphological, particle size, optical properties and degradation ability of annealed nanostructured ZnO were characterized by X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM) and UV-VIS Spectrometer, respectively. XRD results demonstrated a pure crystalline hexagonal wurtzite with crystalline size equal to 23 nm. From AFM results, the average particle size was 79.25nm. All MB samples and MB with annealed nanostr
... Show MoreThis study was carried out in Baghdad (Al-Jadiriya) in 2006 by detecting ability of aquatic reed plant to remove heavy metals (Chromium) from waste water by batch process of adsorption with considering that acidic solution is best selection for such process with constant initial chromium concentration(60 mg/l),speed of shaking(300 rpm), temperature (30 Co) and constant contact time (4 h) but with different weights of adsorbent (reed) (0.5 ,1 ,2 ,3 and 4 )gm for each 100 ml volume of sample . The results showed that the percentage of the removed chromium were ( 8% ,17.5% ,31% ,40% and 50%) respectively for each sample according to the mass of adsorb
... Show MoreIn this research various of 2,5-disubstituted 1,3,4-oxadiazole (Schiff base, oxo-thiazolidine , and other compounds) were synthesized from 2,5-di(4,4?- amino-1,3,4-oxadiazole ) which use quently synthesized from mixture of 4-amino benzoic acid and hydrazine in the presence of polyphosphorus acid. The synthesized compounds were characterized by using some Spectral data (UV, FT-IR, and 1H-NMR).