In this work, the occurrence conditions of both local Bifurcation and persistence were studied, Saddle-node bifurcation appears near fourth point, near the first point, the second point and the third point a transcritical bifurcation occurred but no pitchfork bifurcation happened near any of the four equilibrium points. In addition to study conditions for Hopf-bifurcation near positive stable point that is the fourth point. Besides discuss persistence occurrence as globally property of the food chain of three species include prey, first predator and top predator with impact of toxin in all species and harvesting effect on the predator’s only. Numerical results for the set of hypothetical of parameters come to confirm our analytical results about illustration the occurrence of local bifurcation and persistence of this model.
Stick- slip is the continuous stopping& release of the Bit/BHA due to the irregular down-hole rotation prompted by the existing relationship between the friction torque and the torque applied from the surface to free the bit.
Friction coefficient between BHA and wellbore is the main player of stick slip amount, which can be mitigated by support a good lubricators as additives in drilling mud.
Mathematical (or empirical) solves should be done through adjusting all parameters which supposed to reduce stick- slip as low as possible using different models, one of the main parameters is drilling mud. As per Nanoparticles drilling fluid is a new technology that offers high performance
... Show MoreQuantitative real-time Polymerase Chain Reaction (RT-qPCR) has become a valuable molecular technique in biomedical research. The selection of suitable endogenous reference genes is necessary for normalization of target gene expression in RT-qPCR experiments. The aim of this study was to determine the suitability of each 18S rRNA and ACTB as internal control genes for normalization of RT-qPCR data in some human cell lines transfected with small interfering RNA (siRNA). Four cancer cell lines including MCF-7, T47D, MDA-MB-231 and Hela cells along with HEK293 representing an embryonic cell line were depleted of E2F6 using siRNA specific for E2F6 compared to negative control cells, which were transfected with siRNA not specific for any gene. Us
... Show MoreModern radiotherapy facilities like 3-Dimensional conformal radio therapy (3DCRT), Intensity Modulated Radiotherapy (IMRT), were recently suggested in Co-60 machine with Multi-leaf Collimator (MLC). In this study, two reference chambers NE-2571#1205 and NE2581#537 were used for absolute dose measurement in Equinox accelerator. A comparison of dose measurement by two different IAEA protocols TRS-277 and TRS-398 has been studied. Analyzing TRS-398, a common shaped empirical formula was developed for the four Co-60 units of four Medical Colleges in Bangladesh with fitting parameters. It was found that an average discrepancy in the determination of absorbed dose in water among the two different protocols TRS-277 and TRS-398 were 1
... Show MoreBiodiesel production process was attracted more attention recently due to the surplus quantity of glycerol (G) as a byproduct from the process. Glycerol Utilization must take in to consideration to fix this issue also, to ensure biodiesel industry sustainability. Highly amount of Glycerol converted to more benefit material Glycerol carbonate (GC) was one of the most allurement compound derived from glycerol by transesterification of glycerol with dimethyl carbonate (DMC). Various parameters have highly impact on transesterification was investigated like catalyst loading (1-5) %wt., molar ratio of DMC: glycerol (5:1 – 1:1), reaction time (30 - 150) min and temperature (40 – 80) ᴼC. The Optimum glycerol carbonate yie
... Show MoreSolid‐waste management, particularly of aluminum (Al), is a challenge that is being confronted around the world. Therefore, it is valuable to explore methods that can minimize the exploitation of natural assets, such as recycling. In this study, using hazardous Al waste as the main electrodes in the electrocoagulation (EC) process for dye removal from wastewater was discussed. The EC process is considered to be one of the most efficient, promising, and cost‐effective ways of handling various toxic effluents. The effect of current density (10, 20, and 30 mA/cm2), electrolyte concentration (1 and 2 g/L), and initial concentration of Brilliant Blue dye (15 and 30 mg/L) on
The efficacy of five insect growth regulators has been tested against white fly larva Alearoclava jasimini on citrus tree orchards. Data from field tl'ia ls con finned that percent mortalities were 43.7, 33.9, 23.7, 20.8 and 12.3 for Admiral ( I miL) pyriproxefen, Nomol t 1 5 SC (!milL) Teflubenzuren , Match 050 EC ( I milL ) Lufenuren , cascade I 0 F.C (
0.9mi/L) flufenoxaron, and Dimiline 10 EC ( I milL) Difluben- zuron. The result indicated that Admiral and Nomolt have a continuous effect for one month , so the treatment needs to be repeated for each four weeks. Also, Admiral and Nomolt effect against eggs hatching by 41. 3 % and
In this paper the concept of (m, n)- fully stable Banach Algebra-module relative to ideal (F − (m, n) − S − B − A-module relative to ideal) is introducing, we study some properties of F − (m, n) − S − B − A-module relative to ideal and another characterization is given
ABSTRACT Background: work-related musculoskeletal disorders represent an important occupational health issues among dentists especially neck and low back complaints. Biomarkers of tissue damage as results of occupational physical demands could be used for detection of work related musculoskeletal disorders. Aim: The aim of this study was to assess work- related musculoskeletal disorders, physical work load index, selected salivary biomarkers (Creatine kinase and C - reactive protein) and to find the relation among them. Subjects and Methods: Study participants are consisted of 112 dentists. They were selected from college of dentistry /Baghdad University, health care center in Bagdad city. They were of both gender and aged between 40-45 yea
... Show MoreIn the mist of developments in the course of scientific research in general and humanities in particular and the accompanying changes in the visions and policies inspired by the need for these sciences to follow the qualitative methods in dealing with many of the topics or problems that require for their solution to obtain qualitative information which can be provided by resorting to quantitative research. Therefore, a new trend has emerged in many public relations› researchers who believe that qualitative research methods should be used by establishing scientific foundations and methodological classification based on the use of these methods and determining the nature of the subjects applied in them to reach results that are character
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