• Environmental Engineering Research
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• 제18권4호
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• pp.247-252
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• 2013

In this work, removal of phenol from aqueous solutions by activated red mud was investigated. Scanning electron microscopy and energy dispersive X-ray spectroscopy was used to observe the morphology and surface components of activated red mud, respectively. The effects of various parameters on the removal efficiency were studied, such as contact time, pH, initial phenol concentration, and adsorbent dosage. The removal percentage of phenol was initially increased, as the solution pH increased from 3 to 7, and then decreased above neutral pH. The removal percentage of phenol was decreased by increasing the initial phenol concentrations. Adsorption results show that equilibrium data follow the Freundlich isotherm, and kinetic data was well described by a pseudo-second-order kinetic model. Experimental results show that the activated red mud can be used to treat aqueous solutions containing phenol, as a low cost adsorbent with high efficiency.

• Computers and Concrete
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• 제22권2호
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• pp.197-207
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• 2018

In the present study, group method of data handling networks (GMDH) are adopted and evaluated for shear strength prediction of both FRP-reinforced concrete members with and without stirrups. Input parameters considered for the GMDH are altogether 12 influential geometrical and mechanical parameters. Two available and very recently collected comprehensive datasets containing 112 and 175 data samples are used to develop new models for two cases with and without shear reinforcement, respectively. The proposed GMDH models are compared with several codes of practice. An artificial neural network (ANN) model and an ANFIS based model are also developed using the same databases to further assessment of GMDH. The accuracy of the developed models is evaluated by statistical error parameters. The results show that the GMDH outperforms other models and successfully can be used as a practical and effective tool for shear strength prediction of members without stirrups ($R^2=0.94$) and with stirrups ($R^2=0.95$). Furthermore, the relative importance and influence of input parameters in the prediction of shear capacity of reinforced concrete members are evaluated through parametric and sensitivity analyses.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.3981-3986
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• 2012

Anatase nanocrystalline and its tungsten-doped (0.4, 2, and 4 mol %) powders have been synthesized by microwave irradiation through hydrolysis of titanium tetra-isopropoxide (TIP) in aqueous solution. The materials are characterized by XRD, Raman, SEM-EDX, TEM, FT-IR and UV-vis techniques. The nanocrystalline $TiO_2$ particles are 30 nm in nature and doping of tungsten ion decreases their size. As seen in TEM images, the crystallites of W (4 mol %) doped $TiO_2$ are small with a size of about 10 nm. The photocatalytic activity was tested on the degradation of 4-nitrophenol (4-NP). Catalytic activities of W-doped and pure $TiO_2$ were also compared. The results show that the photocatalytic activity of the W-doped $TiO_2$ photocatalyst is much higher than that of pure $TiO_2$. Degradation decreases from 96 to 50%, during 115 min, when the initial 4-NP concentration increases from 10 to 120 ppm. Maximum degradation was obtained at 35 mg of photocatalyst.

• Transactions on Electrical and Electronic Materials
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• 제13권3호
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• pp.111-115
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• 2012

Spray pyrolysis method was applied for the preparation of indium oxide ($In_2O_3$) thin films, by varying the substrate temperature range from 400-$600^{\circ}C$. All the samples were characterized at room temperature by using X-Ray diffraction, Scanning electron microscopy, Atomic Force Microscopy, Hall Effect and UV-Visible spectrophotometry. The optimal substrate temperature required for obtaining films of high crystallographic quality was $575^{\circ}C$. By comparing optical transmittance and electrical conductivity it was observed that the best figure of merit for these films was achieved for the same temperature and electrical resistivity was in the order of ${\rho}=1.47{\times}10^{-1}[{\Omega}cm]$. Gas sensing measurements of the films in ethanol showed enhancement with surface roughness and sheet resistance.

• Journal of Menopausal Medicine
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• 제24권3호
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• pp.169-175
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• 2018

Objectives: The rate of metabolic syndrome (MetS) in women diagnosed as they age is one of the main concerns of health cares. Recently new strategies used to prevent progressions of MetS toward the diagnosis of diabetes have focused on plant flavonoids. This study was aimed to investigate the beneficial effects of flavonoids fraction of Mespilus germanica leaves (MGL) on MetS in ovariectomized (OVX) rats. Methods: Twenty-four adult female Wistar rats, weighing 200 to 250 g, were divided into 3 groups: Sham surgery, OVX + Salin, or OVX + Flavonoid. Three weeks after ovariectomy, animals displayed MetS criteria received flavonoid injection (10 mg/kg, intraperitoneally) for 21 days. Then the body weight, body mass index, waist circumference, visceral fat, fasting blood glucose, serum insulin, lipid profiles and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) were measured. Results: Treatment with flavonoids fraction of MGL significantly decreased serum level of insulin (P = 0.011), glucose (P = 0.024), $TNF-{\alpha}$ (P = 0.010), also MetS Z score (P = 0.020) and homeostasis model assessment of insulin resistance (P = 0.007). Lipid profiles and visceral fat showed insignificant reduction. Conclusions: Flavonoids of MGL attenuates some of the MetS components possibly via reduction in $TNF-{\alpha}$ inflammatory cytokine.

• Advances in concrete construction
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• 제5권5호
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• pp.423-436
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• 2017

Today, pozzolans are widely used in construction for various reasons such as technical and economic efficiency. In this research, in order to evaluate some of important properties of concrete, silica fume and fly ash have been used as a replacement for cement in different mass percentages. Concrete mixtures were made from a water-cement ratio of (0.45) and cured under similar conditions. The main focus of this study was to evaluate the permeability and mechanical properties of concrete made from binary and ternary cementitious mixtures of fly ash and silica fume. In this study permeability of concrete was studied by evaluating the sorptivity, water absorption, water penetration depth, electrical resistivity and rapid chloride permeability (RCP) tests. Mechanical properties of concrete were evaluated with compressive strength, splitting tensile strength and modulus of elasticity. Scanning electronic microscopy (SEM) was used to characterize the effects of silica fume and fly ash on the pore structure and morphology of concrete with cement based matrix. The results indicated that the incorporation of silica fume and fly ash increased the mechanical strength and improved the permeability of concrete.

• 한국어병학회지
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• 제34권2호
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• pp.169-176
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• 2021

Parasitic infection is among the most common problems for carp cultivation. They are also important for the principal entrance of other hazardous infections as well. This study was carried out for determining of parasitic fauna of two major carp known as silver and grass carp with the comparison of prevalence value and intensity rate of parasites among them, alongside the relationship between the biometric characteristics and host sex with the infection level. For this purpose, a total of 94 fish samples were caught randomly using a fishing net, from Guilan ponds during spring and summer of the year 2018 and transported alive to the laboratory. Upon arriving, the biometric characteristics and genus of each carp were measured individually. Specimens were then acquired from the skin, gills, and eyes of the carp and examined according to standard parasitology methods. Recovered parasites were observed under a light microscope and then fixed for identification. As the result, the occurrence and intensity in the higher length group were comparatively greater than the lower one. Also, the prevalence and intensity of total parasites in male carp were higher than in females. In this research, Dactylogyrus hypophthalmichthys and Dactylogyrus aristhichtys were observed in silver carp and Dactylogyrus lamellatus was detected in grass carp. In the paper below, we found that the host specificity varies in different species of Dactylogyrus isolated from grass carp and silver carp.

• 호남수학학술지
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• 제26권1호
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• pp.77-83
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• 2004

A class of topological algebras, which we call it a fundamental one, has already been introduced generalizing the famous Cohen factorization theorem to more general topological algebras. To prove the generalized versions of Cohen's theorem to locally multilplicatively convex algebras, and finally to fundamental topological algebras, the completness of the background spaces is one of the main conditions. The local convexity of the completion of a locally convex space is a well known fact and here we have a discussion on the completness of fundamental metrizable topological vector spaces.

• 호남수학학술지
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• 제23권1호
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• pp.5-14
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• 2001

Let E be an injective module over a commutative Noetherian ring A. In this paper we will show that if I is regular ideal, then the sequence of sets $$Ass_A((I^n)^{{\star}(E)}/I^n),\;n{\in}N$$ is ultimately constant. Also we obtain some related results. (Here for an ideal J of A, $J^{{\star}(E)}$ denotes the integral closure of J relative to E.

• 호남수학학술지
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• 제27권2호
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• pp.205-209
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• 2005

In this paper we discuss on the uniquenss of the solution of partial differential equations: (1) $${\frac{{\partial}w}{{\partial}{\bar{z}}}}=F(z,\;w,\;{\frac{{\partial}w}{{\partial}z}}}+G(z,\;w.{\bar{w})$$ in the sobolev space $W_{1,p}(D)$.