Preferred Language
Articles
/
ijs-4923
The Effect of Mutual Interaction and Harvesting on Food Chain Model
...Show More Authors

       This paper treats the interactions among four population species. The system includes one mutuality prey, one harvested prey and two predators. The four species interaction can be described as a food chain, where the first prey helps the second harvested prey. The first and the second predator attack the first and the second prey, respectively, according to Lotka-Volterra type functional responses. The model is formulated using differential equations. One equilibrium point of the model is found and analysed to reveal a threshold that will allow the coexistence of all species. All other equilibrium points of the system are located, with their local and global stability being assessed. To back up the conclusions of the mathematical analysis, a numerical simulation examination of the model is carried out. The system's coexistence can be achieved as long as the harvesting rate of the prey population is lower than its intrinsic growth rate.

Scopus Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Jan 01 2022
Journal Name
Applied Ecology And Environmental Research
EFFECT OF SPRAYING WITH FOLIC ACID AND YEAST EXTRACT ON THE GROWTH, YIELD AND CALCIUM OXALATE CONCENTRATION OF SPINACH (SPINACIA OLERACEA L.)
...Show More Authors

View Publication
Scopus (5)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Mon Apr 24 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Synthesis Of Nanostructured TiO2 Thin Films By Pulsed Laser Deposition (PLD) And The Effect Of Annealing Temperature On Structural And Morphological Properties
...Show More Authors

  In this work, nanostructured TiO2 thin films were grown by pulsed laser deposition (PLD) technique on glass substrates. TiO2 thin films then were annealed at 400-600 °C in air for a period of 2 hours. Effect of annealing on the structural and morphological were studied. Many growth parameters have been considered to specify the optimum conditions, namely substrate temperature (300 °C), oxygen pressure (10-2 Torr), laser fluence energy density (0.4 J/cm2), using double frequency Q-switching Nd:YAG laser beam (wavelength 532nm), repetition rate  (1-6 Hz) and the pulse duration of 10 ns. The results of the X-ray test show that all nanostructures tetragonal are polycrystalline. These results show that grain size increase fr

... Show More
View Publication Preview PDF
Publication Date
Thu May 25 2023
Journal Name
Polycyclic Aromatic Compounds
Effect of Modified Nano-Graphene Oxide and Silicon Carbide Nanoparticles on the Mechanical Properties and Durability of Artificial Stone Composites from Waste
...Show More Authors

Sludge from stone-cutting (SSC) factories and stone mines cannot be used as decorative stones, stone powder, etc. These substances are left in the environment and cause environmental problems. This study aim is to produce artificial stone composite (ASC) using sludge from stone cutting factories, cement, unsaturated resin, water, silicon carbide nanoparticles (SiC-NPs), and nano-graphene oxide (NGO) as fillers. Nano graphene oxide has a hydrophobic plate structure that water is not absorbed due to the lack of surface tension on these plates. NGO has a significant effect on the properties of artificial stone due to its high specific surface area and low density in the composite. Its uniform distribution in ASC is very low due to its hydropho

... Show More
View Publication
Scopus (1)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
Effect of Welded Joints Design on the Joint Strength During Statie and Dynamie Loading with Different Current and Type of Wire Welding
...Show More Authors

The aim of this research is to study the effect of welded joint design (Butt joint and lap joint) on thejoint strength during tension and fatigue loading with different current of welding (40,50,60,70,80) ^per, and different type of wire welding. The result of this research is showed that the effect of fatigue loading on the type of joint is more than the effect of tension loading on it. And the butt joint welding is better than the lap joint welding during the fatigue loaded.The experimental results of the effect of W'elding current showed that more increasing and more decreasing the value of the heat input, during the welding was found to produce mechanical brittleness on the buttjoint welding during the static and dynamic loading. Also i

... Show More
View Publication Preview PDF
Publication Date
Mon Jun 17 2019
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Effect of Two Antigen Preparations From Group A Streptococcus on Phagocytosis and Cellular Counts of Neutrophils and Monocytes in Albino Mice
...Show More Authors

The phagocytic activity of peritoneal and blood cells counts with neutrophils and monocytes were evaluated in albino mice treated wtth two antigen preparations (A and B) from group A streptococci (GAS). Antigen A included water bathed bacteria at 70 °C for 60 minutes, while in Antigen B the bacteria was autoclaved at 121° C for 15 minutes. The animals were treated with 12 intraperitoneal doses of the antigens with intervals of three days (36 days). The 12th dose was a challenge dose (live bacteria). The first three doses of Antigen A increased the phagocytic index (PI) to a range of 76.46-78.69%, then a gradual decreased percentage was observed, especially at the challenge dose (PI=6.42%). The count of neutrophils and monocytes fol

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 26 2019
Journal Name
Iraqi Journal Of Science
Modeling and Forecasting Periodic Time Series data with Fourier Autoregressive Model
...Show More Authors

Most frequently used models for modeling and forecasting periodic climatic time series do not have the capability of handling periodic variability that characterizes it. In this paper, the Fourier Autoregressive model with abilities to analyze periodic variability is implemented. From the results, FAR(1), FAR(2) and FAR(2) models were chosen based on Periodic Autocorrelation function (PeACF) and Periodic Partial Autocorrelation function (PePACF). The coefficients of the tentative model were estimated using a Discrete Fourier transform estimation method. FAR(1) models were chosen as the optimal model based on the smallest values of Periodic Akaike (PAIC) and Bayesian Information criteria (PBIC). The residual of the fitted models was diagn

... Show More
View Publication Preview PDF
Scopus (2)
Crossref (1)
Scopus Crossref
Publication Date
Thu Feb 06 2025
Journal Name
Journal Of Baghdad College Of Dentistry
The effect of addition of untreated and oxygen plasma treated polypropylene fibers on some properties of heat cured acrylic resin
...Show More Authors

Background: The polymethyl methacrylate is the most reliable material for the construction of complete and partial dentures, despite satisfying esthetic demand itsuffered from having unsatisfactory properties like impact strength and transverse strength. This study was designed to improve the impact strength and transverse strength of heat cure acrylic resin by adding untreated and oxygen plasma treated polypropylene fibers and investigate the effect of this additive on some properties of acrylic resin materials. Materials and methods: Untreated and oxygen plasma treated polypropylene fibers was added to PMMA powder by weight 2.5 %. Specimens were constructed and divided into 5 groups according to the using tests; each group was subdivided

... Show More
View Publication Preview PDF
Publication Date
Thu Feb 06 2025
Journal Name
Journal Of Baghdad College Of Dentistry
The effect of addition of hydroxyapatite microscopic fillers on surface roughness and some mechanical properties of heat cured acrylic resin
...Show More Authors

Background: this study aimed to evaluate the effect of addition of hydroxyapatite micro filler in three concentrations (5%, 10%, 15%) on surface roughness, impact strength, flexural strength and hardness. Material and methods: One hundred sixty acrylic samples were used in this study,40 samples were used for each test(impact strength ,flexural strength ,hardness and surface roughness).The test group divided into four subgroups(n=10) for controlgroup,5%,10% ,15%H,A.concentration addition groups .Impact testing device, flexural strength testing device, shore hardness tester and profilometer device were used to measure the four tests examined in this study. Results: the results showed a significant increase in impact strength, hardness in all

... Show More
View Publication Preview PDF
Publication Date
Thu Feb 06 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Histological and immunohistochemical evaluation of the effect of local exogenous application of VEGF on bone healing (experimental study in rat)
...Show More Authors

Background: The repair of bone defects remains a major clinical orthopaedic challenge. Bone is a highly vascularised tissue reliant on the close spatial and temporal connection between blood vessels and bone cells to maintain skeletal integrity. Angiogenesis thus plays a pivotal role in skeletal development and bone fracture repair. The role of angiogenic and osteogenic factors in the adaptive response and interaction of osteoblasts and endothelial cells during the multi step process of bone development and repair will be highlighted in this study. This study aimed to identify the role of local exogenous vascular endothelial growth factor in bone healing and to analyze the expression of VEGF by immunohistochemistry in created bone defect af

... Show More
View Publication Preview PDF
Publication Date
Sun Aug 13 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Effect of Different levels and kinds of Cytokinins on Buds proliferation of Iraqian Date Palm Cultiver (Barhi) In vitro
...Show More Authors

The present study was conducted to determined the action of several levels of cytokinis (N6-benzyladenine (BA),  6-furfurylaminopurine (kinetin), N6-(∆-isopentyladenine) (2,ip) on buds proliferation of Phoenix dactylifera L..3 ml explants of the heart of 3 years old offshoot were cultured on Murashige and Skoog medium (1962) containing 3 mg/L activated charcoal, 10 mg/L Naphthalene acetic acid  proposed by (1) as a control. Other explants were cultured on this medium supplemented with 0.1, 0.5, 1 mg/L BA. 0.1, 0.5, 1, 2, 3, 4 mg/L Kinetin. 0.1, 0.5, 1 mg/L 2,ip. Best number of buds proliferated has occurred on control medium containing 3 mg/L. 2ip.

View Publication Preview PDF