Understanding how abiotic influences affect organisms and their interactions within ecological communities has long been of interest to ecologists. The significance of this comprehension has increased given rapid human-induced climate change. Wind speed variation is one of the less researched effects of climate change, as wind speeds worldwide are generally falling. Although wind is a fairly universal component of the environment, relatively little work has been conducted to integrate our knowledge of how wind affects interactions between different species. In this study, the influence of wind on bottom-up trophic interactions in the plant–ungulate–wolf food chain has been investigated through mathematical modeling. Positivity and boundedness of the model have been proven, and the existence of equilibrium points and their stability have been established. Saddle-node, transcritical, and Hopf bifurcations are discussed. Finally, all theoretical results are confirmed by numerical simulations.
In this research, the one of the most important model and widely used in many and applications is linear mixed model, which widely used to analysis the longitudinal data that characterized by the repeated measures form .where estimating linear mixed model by using two methods (parametric and nonparametric) and used to estimate the conditional mean and marginal mean in linear mixed model ,A comparison between number of models is made to get the best model that will represent the mean wind speed in Iraq.The application is concerned with 8 meteorological stations in Iraq that we selected randomly and then we take a monthly data about wind speed over ten years Then average it over each month in corresponding year, so we g
... Show MorePolyvinyl chloride (PVC) finds use in various industries due to its versatility but is not thermostable, serving as a barrier to causing degradation and release of hydrochloric acid (HCl) under heat stress conditions. Lead and organotin compounds have traditionally been used for stabilizer purpose to discourage such degradation but pose serious ecological as well as health risks. As a counter measure, bio-based stabilizers from plant oils have become popular as a green and sustainable alternative. This review looks back at recent developments in plant oil-based stabilizers for PVC, focusing on the mechanisms of stabilization, sustainability, and cost-effectiveness. We review plant oils such as tung oil, castor oil, and soybean oil,
... Show MoreThe essay discusses how different environmental factors affect plant growth by explaining how each factor affects the physiological processes within the plant. The essay begins by explaining the effect of temperature on plant growth, as high or low temperatures can significantly affect the rate of photosynthesis and lead to a reduction in water and nutrient absorption. It also discusses the light intensity impacting plants because the more appropriate the light intensity is, the more enhanced the plant's photosynthesis ability, and in the excess or insufficient light condition, the growth can be inhibited. Additionally, the article outlines the effect of water shortage on the plant because this leads to the closure of stomata to avoid water
... Show MoreObjectives: To assess the performance of a novel resin-modified glass-ionomer cement (pRMGIC) bonded to various tooth tissues after two-time intervals. Methods: 192 sound human molars were randomly assigned to 3 groups (n = 64): sound enamel, demineralised enamel, sound dentine. Sixty-four teeth with natural carious lesions including caries-affected dentine (CAD) were selected. All substrates were prepared, conditioned and restored with pRMGIC (30% ethylene glycol methacrylate phosphate (EGMP, experimental), Fuji II LC (control), Fuji IX, and Filtek™ Supreme with Scotchbond ™ Universal Adhesive. Shear bond strength (SBS) was determined after 24 h and three months storage in SBF at 37C. The debonded surfaces were examined using stereomi
... Show MoreSewer system plays an essential task in urban cities by protecting public health and the environment. The operation, maintenance, and rehabilitation of this network have to be sustainable and scientifically. For this purpose, it is crucial to support operators, decision makers and municipalities with performance evaluation procedure that is based on operational factors. In this paper, serviceability and performance indicator (PI) principles are employed to propose methodology comprising two enhanced PI curves that can be used to evaluate the individual sewers depending on operational factors such as flowing velocity and wastewater level in the sewers. To test this methodology; a case study of al-Rusafa in Baghdad city is
... Show MoreSewer system plays an indispensable task in urban cities by protecting public health and the environment. The operation, maintenance, and rehabilitation of this network have to be in a sustainable and scientific manner. For this purpose, it is important to support operators, decision makers and municipalities with performance evaluation procedure that is based on operational factors. In this paper, serviceability and performance indicator (PI) principles are employed to propose methodology comprising two enhanced PI curves that can be used to evaluate the individual sewers depending on operational factors such as flowing velocity and wastewater level in the sewers. In order to test this methodology; a case study of al-Ru
... Show MoreCompaction curves are widely used in civil engineering especially for road constructions, embankments, etc. Obtaining the precise amount of Optimum Moisture Content (OMC) that gives the Maximum Dry Unit weight gdmax. is very important, where the desired soil strength can be achieved in addition to economic aspects.
In this paper, three peak functions were used to obtain the OMC and gdmax. through curve fitting for the values obtained from Standard Proctor Test. Another surface fitting was also used to model the Ohio’s compaction curves that represent the very large variation of compacted soil types.
The results showed very good correlation between the values obtained from some publ
... Show MoreIn recent years, literary studies have witnessed a remarkable shift towards employing digital technologies, particularly artificial intelligence tools, in analyzing literary texts and exploring their linguistic and semantic structures. This trend has provided researchers with new possibilities for understanding texts in quantitative and qualitative ways that transcend traditional methods based solely on critical reading. The current research aims to introduce professors and students of Arabic to artificial intelligence tools that contribute to the analysis of literary texts, focusing on exploring their mechanisms for studying style, meaning, structure, and emotion. It also seeks to highlight the most prominent challenges facing researchers
... Show MoreIn this research, a modified artificial hand with direct control has been designed using electrical artificial muscle wires that receive direct sensory impulses through human hand instead of using the mechanical action to open and close this artificial hand. Each finger is designed as a chain and its movements achieved through the conventional arrangement control of the electrical muscles wires. The results indicate that it is possible to design an artificial hand using electrical muscle wire for control it with high accuracy.