This work aims to analyze a three-dimensional discrete-time biological system, a prey-predator model with a constant harvesting amount. The stage structure lies in the predator species. This analysis is done by finding all possible equilibria and investigating their stability. In order to get an optimal harvesting strategy, we suppose that harvesting is to be a non-constant rate. Finally, numerical simulations are given to confirm the outcome of mathematical analysis.

The degradation performance of aqueous solution of pesticide Alachlor has been studied at solar pilot scale plant in two photocatalytic systems: homogeneous photocatalysis by photo-Fenton and heterogeneous photocatalysis with titanium dioxide. The pilot scale system included of compound parabolic collectors specially designed for solar photocatalytic applications, and installed at University of Baghdad, Department of Environmental Engineering back yard. The influence of different concentrations, H₂O₂ (200-2400 mg/l), Fe⁺²(5- 30 mg/l) and TiO2 (100-500 mg/l) and their relationship with the degradation efficiency were studied.

      The COD removal efficienc

         Recently, emulgel has emerged as one of the most interesting topical preparations in the field of pharmaceutics. In this research clotrimazole was formulated as topically applied emulgel ; different formulas were prepared. The prepared emulgels were evaluated for their physical appearance , rheological behaviour , and in vitro drug release . The influence of the type of gelling agent (carbopol 934 and methyl cellulose), the concentration of both the emulsifying agent (2% and 4% w/w of mixture of span 20 and tween 20) and the oil phase (5% and 7.5% w/w of liquid paraffin) and the type of oil phase (liquid paraffin and cetyl alcohol), on the drug release from the prepared emulgels was invest

Concrete is widely used in construction materials since early 1800's. It has been known that concrete is weak in tension, so it requires some addition materials to have ductile behavior and enhance its tensile strength and strain capacity to improve their uses. In this study reactive powder concrete (RPC) was used with steel fiber by using different types of cement; (Ordinary Portland cement (OPC) and/or Portland- Limestone cement (PLC)) with three types of mixtures (OPC at the first mix, 50 % OPC and 50 % PLC at the second mix and PLC at the third mix). The behavior of RPC with steel fibers on compressive strength and tensile strength of concrete with different ages of curing (7, 14, 28 and 60) days and shrinkage have been studied. The clo

In this research study Hardness (shore D), Water absorption,
Flexural, Impact Test, and Fracture Toughness of polymer nano
composites. The polymer nano composites based on unsaturated
polyester resin reinforced with Kevlar fibers (K.F). The samples are
attended by hand lay – up method according to (Rule mixture) for
various volume fractions of unsaturated polyester resin, fiber and
carbon nanotube. The polyester resin was matrix strengthened with
3% volume fraction from Kevlar fiber and (0.5%, 1%, 1.5%, 2%)
volume fractions of carbon nanotube. The water absorption, hardness
(shore D), flexural test, impact test and toughness fracture properties
were studied. Results showed that the water absorption increas

Background: Numerous methods have been described for achievement of Intermaxillary fixation in the treatment of fractures of facial skeleton. Conventional methods like Erich arch bars and eyelet wires are currently the most common methods for achieving intermaxillary fixation (IMF), however, they have their own disadvantages. Since 1989, IMF using intraoral self-tapping IMF screws has been introduced for treatment of mandibular fractures. The aim of this study was to evaluate the efficacy, advantages, disadvantages and potential complications associated with using of self-tapping IMF screws in the treatment of mandibular fractures. Material and Methods: Twenty patients with favorable mandibular fractures, attended to Oral and Maxillofacial

The present researchers are trying to enhance the properties of paper sheet that used widely in many fields such as printing and packaging. The enhancement of paper quality is also possible to preserve paper documents of all kinds, as they are the true record, full of the history, achievements of the human being and the intellectual and cultural of the country. It is possible to improve its physical and mechanical properties and preserve them from damage through the use of some solutions of polymeric adhesives, which act as protective barriers against water and moisture penetration. The paper also has the advantage of porosity, which has been overcome by using three types of polymeric adhesives (Nitro Cellulose, Polyvinyl alcohol acetate, a

Stone Matrix Asphalt (SMA) is a gap-graded asphalt concrete hot blend combining high-quality coarse aggregate with a rich asphalt cement content. This blend generates a stable paving combination with a powerful stone-on-stone skeleton that offers excellent durability and routing strength. The objectives of this work are: Studying the durability performance of stone matrix asphalt (SMA) mixture in terms of moisture damage and temperature susceptibility and Discovering the effect of stabilized additive (Fly Ash ) on the performance of stone matrix asphalt (SMA) mixture. In this investigation, the durability of stone matrix asphalt concrete was assessed in terms of temperature susceptibility, resistance to moisture damage, and sensitivity t