140 research outputs found
of compound open channel
Distribution of velocity of flow in compound open channel due to interaction of floodplains and main channel is strongly non-uniform. Defining the distribution of flow velocity is an important factor in calculation of sediment transport and estimation of flow discharge. One of the correction factors in calculation of flow discharge and shear stress are momentum( ) and energy ( ) coefficients. In this study, the effect of and coefficients on Froude number and specific energy are assessed. Stage-discharge relationship in compound open channel was assessed using some empirical formula including Single-Channel Method (SCM), Divided-Channel Method (DCM), and modified divided-channel method (MDCM) and compared with together. When the discharge only flows in main channel all the empirical has a same result whereas by increasing the discharge and covering the floodplains by flow the results of them are different. The highest value of outcome of empirical formula is related to the SCM. Results indicated that considering the energy and momentum coefficients have significant effect on distribution of Froude number and specific energy
A comparison of artificial intelligence approaches in predicting discharge coefficient of streamlined weirs
In the present research, three different data-driven models (DDMs) are developed to predict the discharge coefficient of streamlined weirs (C-dstw). Some machine-learning methods (MLMs) and intelligent optimization models (IOMs) such as Random Forest (RF), Adaptive NeuroFuzzy Inference System (ANFIS), and gene expression program (GEP) methods are employed for the prediction of C-dstw. To identify input variables for the prediction of C-dstw by these DMMs, among potential parameters on C-dstw, the most effective ones including geometric features of streamlined weirs, relative eccentricity (lambda), downstream slope angle (beta), and water head over the crest of the weir (h(1)) are determined by applying Buckingham pi-theorem and cosine amplitude analyses. In this modeling, by changing architectures and fundamental parameters of the aforesaid approaches, many scenarios are defined to obtain ideal estimation results. According to statistical metrics and scatter plot, the GEP model is determined as a superior method to estimate C-dstw with high performance and accuracy. It yields an R-2 of 0.97, a Total Grade (TG) of 20, RMSE of 0.032, and MAE of 0.024. Besides, the generated mathematical equation for C-dstw in the best scenario by GEP is likened to the corresponding measured ones and the differences are within 0-10%
Active Tumor-Targeting by Smart Nanocarriers: A Potential Promising Approach to Overcome the Hurdles of Conventional Cancer Treatments
Cancer is one of the most momentous and intricate life-threatening health problems which despite routine and combination treatments are still accompanied by high mortality worldwide (Gorgich et al., 2017). Because tumor cells have rapid and uncontrolled proliferation compare to normal cells, they need more nutrients, which in turn for supplying it begins to alter normal cellular signaling pathways and extensive angiogenesis in the specific tumor microenvironment (TME). During tumorigenesis, tumor cells undergo intra/extracellular specific biological changes as a result of increased metabolic requirements. These changes lead to overexpression of cell surface receptors, increased membrane channels and transporters (Heidari et al., 2017; Ancey et al., 2018). Based on these facts, diagnostic and therapeutic strategies can be designed for tumor-cells targeting. © 2021. All Rights Reserved
Synthesis, characteristics, and photocatalytic activity of zinc oxide nanoparticles stabilized on the stone surface for degradation of metronidazole from aqueous solution
Background: The presence of antibiotics such as metronidazole in wastewater even at low concentrations
requires searching for a suitable process such as advanced oxidation process (AOP) to reduce the level
of pollutants to a standard level in water.
Methods: In this study, zinc oxide (ZnO) nanoparticles were synthesized by thermal method using zinc
sulfate (ZnSO4) as a precursor, then, stabilized on stone and was used as a catalyst, in order to degrade
metronidazole by photocalytic process. Effective factors on the removal efficiency of metronidazole
including the initial metronidazole concentration, contact time, pH, and 0.9 gL-1 ZnO stabilized on the
stone surface were investigated.
Results: The X-ray diffraction (XRD) studies showed that the synthesized nanomaterials have hexagonal
Wurtzite structure. Also, scanning electron microscopy (SEM) analysis revealed that the average
crystalline size of the synthesized ZnO particles was in the range of 1.9-3.2 nm. The spectra represented
a sharp absorption edge at 390 nm for ZnO nanoparticles corresponding to band gap of 3.168 eV.
The BET-BJH specific surface area of the synthesized ZnO nanoparticles was 25.504 m2/g. The EDS
spectrum of ZnO nanoparticles showed four peaks, which were identified as Zn and O. The maximum
removal efficiency was 98.36% for the synthetic solution under a specific condition (pH = 11, reaction
time = 90 minutes, ZnO concentration = 0.9 gL-1, and the initial concentration of metronidazole = 10
mgL-1). The photocatalytic degradation was found to follow pseudo-first-order degradation kinetics.
Conclusion: Therefore, the ZnO nanoparticles synthesized by thermal decomposition are suitable and
effective photocatalytic materials for degradation of pharmaceutical contaminants.
Keywords: Zinc oxide, Metronidazole, Ultraviolet rays, Nanoparticle
Analysis of antibody production in Saccharomyces cerevisiae: effects of ER protein quality control disruption
Enhancing antibody folding and secretion by tailoring the Saccharomyces cerevisiae endoplasmic reticulum
An Analysis Characterizing the composition of the Corneal Limbal Epithelial Stem Cell Niche (LSCN)
Limbal epithelial stem cells (LESCs) are required for the long-term maintenance of the corneal epithelium and are required to regenerate the corneal epithelium after injury.The loss or damage to LESCs or the LSCN can lead to Limbal stem cell deficiency (LSCD). LSCD causes corneal erosions, neovascularization, and conjunctivalization of the cornea, which leads to ocular pain and vision loss. Hyaluronan (HA) is a constituent of the LSC Niche (LSCN) that is necessary for maintaining LESCs in their stem cell state. My research this summer focused on characterizing the HA-specific LSCN by identifying HA-bound proteins and proteoglycans (PGs) within the limbal region of human and porcine corneas. HA bound proteins and proteoglycans (PGs) were extracted from the central corneas and limbal region. Firstly, we dissected the corneas and used chaotropic agents and mechanical trituration to homogenize the tissues. Then, an anion exchange chromatography was used to isolate HA bound proteins and PGs. Finally, samples were desalted and concentrated.Total protein/PG extracts were analyzed by Western Blotting and agarose gel electrophoresis. Additionally, human corneas were processed for histological analysis. Inter-Alpha Inhibitor (IaI), a molecule that forms specific HA matrices with anti-inflammatory properties, was identified in our samples by both Western blotting and immunohistochemistry. Future studies will work on characterizing the role of this HA/IaI or HA/TSG-6/IaI matrix within the corneal limbus. Characterizing the role of the LSCN is vital for establishing novel mechanisms for treating LSCDBiology and Biochemistry, Department ofHonors Colleg
Prediction of discharge coefficient of triangular labyrinth weirs using Adaptive Neuro Fuzzy Inference System
Calculation of Longitudinal Dispersion Coefficient and Modeling the Pollution Transmission in Rivers (Case studies: Severn and Narew Rivers)
Introduction: The study of rivers’ water quality is extremely important. This issue is more important when the rivers are one of the main sources of water supply for drinking, agriculture and industry. Unfortunately, river pollution has become one of the most important problems in the environment. When a source of pollution is transfused into the river, due to molecular motion, turbulence, and non-uniform velocity in cross-section of flow, it quickly spreads and covers all around the cross section and moves along the river with the flow. The governing equation of pollutant transmission in river is Advection Dispersion Equation (ADE). Computer simulation of pollution transmission in rives needs to solve the ADE by analytical or numerical approaches. The ADE has analytical solution under simple boundary and initial conditions but when the flow geometry and hydraulic conditions becomes more complex such as practical engineering problems, the analytical solutions are not applicable. Therefore, to solve this equation several numerical methods have been proposed. In this paper by getting the pollution transmission in the Severn River and Narew River was simulated.
Materials and Methods: The longitudinal dispersion coefficient is proportional of properties of Fluid, hydraulic condition and the river geometry characteristics. For fluid properties the density and dynamic viscosity and for hydraulic condition, the velocity, flow depth, velocity and energy gradient slope and for river geometry the width of cross section and longitudinal slope can be mentioned. Several other parameters are influencive, but cannot be clearly measured such as sinuosity path and bed form of river. To derive the governed equation of pollution transmission in river, it is enough to consider an element of river and by using the continuity equation and Fick laws to balancing the inputs and outputs the pollution discharge. To calculate the dispersion coefficient several ways as empirical formulas and artificial intelligent techniques have been proposed. In this study LDC is calculated for the Severn River and Narew River and some selected empirical formulas have been assessed to calculate the LDC.
Dispersion Routing Method: As mentioned previously, calculating the LDC is more important, so firstly, the longitudinal dispersion was calculated from the concentration profile by Dispersion Routing Method (DRM). Using the DRM included the four stage.1-considering of initial value for LDC .2-calculating the concentration profile at the downstream station by using the upstream concentration profile and LDC.3- Performing a comparison between the calculated profile and measured profile.4- if the calculating profile is not a suitable cover, the measured profile of the process will be repeated until the calculated profile shows a good covering on the measured profile.
Numerical Method: The ADE includes two different parts advection and dispersion. The pure advection term is related to transmission modeling without any dispersing and the dispersion term is related to the dispersion without any transmission. To discrete the ADE the finite volume method was used. According to physical properties of these two terms and the recommendation of researchers a suitable scheme should be considered for numerical solution of ADE terms. Among the finite volume schemes, the quickest scheme was selected to discrete the advection term, because of this scheme has suitable ability to model the pure advection term. The quickest scheme is an explicit scheme and the stability condition should be considered. To discrete the dispersion term, the central implicit scheme was selected. This scheme is unconditionally stable.
Results and Discussion: The results of longitudinal dispersion coefficient for the Severn River and Narew River were calculated using the DRM method and empirical formulas. The results of LDC calculation showed that the minimum and maximum values for the Severn River was equal to the 12.5 and 41.5 respectively and for the Narew River were reported as 18.0 and 56.0 respectively. The value of the LDC derived using the DRM was used as one of the input parameters for developing the computer program. For validation of numerical model, a comparison was conducted with results of analytical solution. This comparison showed that the performance of numerical method is quite suitable. For assessing the performance of numerical model the pollution transmission in the both mentioned rivers was simulated. The calculated LDC and time steps and distance steps was considered as 4m and 2s. The results of simulation showed that the performance of developed computer model is suitable for practical purposes.
Conclusion: In this paper the Finite volume method such as numerical model for Discretization the ADE and also estimating the LDS the Dispersion routing method has been used. To primary evaluating of the model the compression between the model result and analytical solution of ADE has been done. To assess the accuracy of the model in engineering work the results of the model compared with two rivers data observations (Severn and Narew). Final result showed that the performance of model is suitable
Improving Modelling of Discharge Coefficient of Triangular Labyrinth Lateral Weirs Using SVM, GMDH and MARS Techniques
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