The steady 3-D raw water turbulent flow is numerically investigated. This flow is formed of solid silica sand (quartz) carried by water in stainless steel pipe. The flow in a straight pipe and flow in a pipe with a sudden contraction are analyzed using a two-way coupled Eulerian-Lagrangian approach. Erosion rate is estimated by Oka erosion model combined with the constant coefficient of restitution. The effect of solid particles mass flow rate, inlet velocity, particle diameter, internal pipe diameter, orientation, contraction coefficient, and wall pipe contraction angle on erosion rate are examined. The predicted erosion is distributed homogenously for straight pipe, while the step wall area of the contraction is the most eroded part. The
... Show MoreThe 3-parameter Weibull distribution is used as a model for failure since this distribution is proper when the failure rate somewhat high in starting operation and these rates will be decreased with increasing time .
In practical side a comparison was made between (Shrinkage and Maximum likelihood) Estimators for parameter and reliability function using simulation , we conclude that the Shrinkage estimators for parameters are better than maximum likelihood estimators but the maximum likelihood estimator for reliability function is the better using statistical measures (MAPE)and (MSE) and for different sample sizes.
Note:- ns : small sample ; nm=median sample
... Show MoreNew series of metal ions complexes have been prepared from the new ligand [2,2′‐(5,5‐dimethylcyclohexane‐1,3‐diylidene)bis(azan‐1‐yl‐1‐ylidene)dibenzoic acid] derived from 5,5‐dimethylcyclohexane‐1,3‐dione and 2‐aminobenzoic acid. Accordingly, mono‐nuclear Ni(II), Pd(II), Re (II), and Pt(IV) complexes were prepared by the reaction of previous ligand with NiCl2.6H2O, PdCl2, ReCl5, and H2PtCl6.6H2O, respectively. The compounds have been characterized by Fourier‐transform infrared (FTIR), ultraviolet–visible (UV–vis), mass, H
The green synthesis of nickel oxide nanoparticles (NiO-NP) was investigated using Ni(NO3)2 as a precursor, olive tree leaves as a reducing agent, and D-sorbitol as a capping agent. The structural, optical, and morphology of the synthesized NiO-NP have been characterized using ultraviolet–visible spectroscopy (UV-Vis), X-ray crystallography (XRD) pattern, Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) analysis. The SEM analysis showed that the nanoparticles have a spherical shape and highly crystalline as well as highly agglomerated and appear as cluster of nanoparticles with a size range of (30 to 65 nm). The Scherrer relation has been used to estimate the crystallite size of NiO-NP which ha
... Show Moresingle and binary competitive sorption of phenol and p-nitrophenol onto clay modified with
quaternary ammonium (Hexadecyltrimethyl ammonium ) was investigated to obtain the
adsorption isotherms constants for each solutes. The modified clay was prepared from
blending of local bentonite with quaternary ammonium . The organoclay was characterized
by cation exchange capacity. and surface area. The results show that paranitrophenol is
being adsorbed faster than phenol . The experimental data for each solute was fitted well with
the Freundlich isotherm model for single solute and with the combination of Freundlich-
Langmuier model for binary system .
In this article, we recalled different types of iterations as Mann, Ishikawa, Noor, CR-iteration and, Modified SP_iteration of quasi δ-contraction mappings, and we proved that all these iterations equivalent to approximate fixed points of δ-contraction mappings in Banach spaces.
Background: We aimed to investigate the accuracy of salivary matrix metalloproteinases (MMP)-8 and -9, and tissue inhibitor of metalloproteinase (TIMP)-1 in diagnosing periodontitis and in distinguishing periodontitis stages (S)1 to S3. Methods: This study was a case–control study that included patients with periodontitis S1 to S3 and subjects with healthy periodontia (controls). Saliva was collected, and then, clinical parameters were recorded, including plaque index, bleeding on probing, probing pocket depth, and clinical attachment level. Diagnosis was confirmed by assessing the alveolar bone level using radiography. Salivary biomarkers were assayed using an enzyme-linked immunosorbent assay. Results: A total of 45 patients (15
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