Sharif Digital Repository

Kinetics and isotherms of adsorption behavior of nanoscale Zr-based metal-organic framework for the removal of three organic dyes including acidic, direct and basic ones from aqueous solutions were studied by sorption models. Nanocube-shaped UiO-66 particles with an average edge length of 215 nm, specific surface area of 1215 m2/g, total pore volume of 0.58 cm3/g, and average pore diameter of 1.8 nm were prepared by solvothermal methods. Analyzing of the equilibrium isotherms indicates that direct dye removal is best fitted with the Langmuir isotherm. Study of the adsorption kinetics also determines that direct dye adsorption follows pseudo-first-order model (R2=0.99). The kinetics of basic... 

Activated carbon (AC) is an inert adsorbent material that has widely been used in water treatment or removing of environmental pollutants from water. In order to improve the adsorption of AC, which highly depends on its pore size and surface area, we prepared highly porous adsorbent composites of activated carbon (AC)/chromium-based MOF (MIL-101(Cr)). The composite has a high specific surface area of 2440 m2 g−1 and total pore volume of 1.27 cm3 g−1. To show the efficiency of the composite as an adsorbent, the removal kinetics of anionic dyes (Direct Red 31 and Acid Blue 92) from aqueous solutions dependent on the amount of composite, adsorption time, concentration of dye and pH is... 

Herein, a magnetic zirconium-based metal-organic framework nanocomposite was synthesized by a simple solvothermal method and used as an adsorbent for the removal of direct and acid dyes from aqueous solution. To enhance its adsorption performance, poly(propyleneimine) dendrimer was used to functionalize the as-synthesized magnetic porous nanocomposite. The dendrimer-functionalized magnetic nanocomposite was characterized by field-emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption/desorption isotherms, and vibration sample magnetometer. The obtained results revealed the successful synthesis and functionalization of the... 

This paper presents a new model of call admission control which consists of a few key elements for protecting the network in different conditions of workload in a manner that, calls blocking /dropping are kept under desired level. This model consists of two traffic classes of voice and data. In order to give a priority to handoff call over new call, some parameters in this model are adjusted in a manner that handoff dropping is reduced to the least probability in the target cell and the adjacent cells. Some channels are reserved for voice and data calls in each cell to guarantee the quality of service requirements in the network. Limited fractional guard channel is used to have an optimized... 

It is not common to build a geomechanical model for depleted reservoirs as logging and coring are costly and time consuming in such reservoirs. On the other hand, in regular analysis of wellbore stability, the effect of time is completely ignored. As a result, with time there will be some errors in the evaluation of wellbore stability in depleted reservoirs. In order to determine the optimum wellbore trajectory during the reservoir life, it is necessary to have a model which can estimate the rock properties based on the first full logging suite and also consider the depletion effect. In this study, a novel model is proposed which combines a mechanical earth model, borehole circumferential... 

The aim of this paper is to investigate the vendor managed inventory (VMI) problem of a single-vendor single-buyer supply chain system, in which the vendor is responsible to manage the buyer's inventory. To include an extended applicability in real-world environments, the multiproduct economic production quantity model with backordering under three constraints of storage capacity, number of orders, and available budget is considered. The nonlinear programming model of the problem is first developed to determine the near optimal order quantities along with the maximum backorder levels of the products in a cycle such that the total VMI inventory cost of the system is minimized. Then, a genetic... 

In today's business transactions, sometimes customers are allowed to pay in a grace period, i.e., permissible delay in payment occurs. This policy is advantageous both for the suppliers and for the customers. This paper formulates a multi-product economic order quantity (EOQ) problem with an order-quantity-dependent permissible delay in payment. In this problem, the shortage is backlogged and there is a warehouse constraint. We show that the model of the problem is a constrained nonlinear-integer-program and propose a genetic algorithm (GA) to solve it. Moreover, a statistical approach is employed to calibrate the parameters of the GA. A numerical example is presented at the end to not only... 

We present enhanced electrocatalytic activity of three-dimensional graphene scaffolds by decoration with one-dimensional CoxNi1-x MOF nanostructures (0 ≤ x ≤ 1). The decreased overpotential and fast kinetics of the oxygen evolution reaction as compared with the existing materials are shown. The developed bimetallic MOF/3DG composites have great potential to be used in electrocatalytic water oxidation. This journal is © The Royal Society of Chemistry  

Call admission control schemes are crucially Important concepts ID researches on cellular mobile networks. One of them is the new thinning scheme. In this study we define a confidence interval for threshold and the numerical results show the performance of the scheme in defined interval. Also we discuss the sensitivity of the scheme (in sample-based sensitivity method) at different thresholds. The results show the better performance in confidence thresholds and sensitivity of scheme into variations of thresholds  

This study aims to develop sunitinib niosomal formulations and assess their in-vitro anti-cancer efficiency against lung cancer cell line, A549. Sunitinib, a highly effective anticancer drug, was loaded in the niosome with high encapsulation efficiency. Collagen was coated on the surface of the niosome for enhanced cellular uptake and prolonged circulation time. Different formulations were produced, while response surface methodology was utilized to optimize the formulations. The stability of the formulations was evaluated over a 2-month period, revealing the importance of collagen coating. MTT assay demonstrated dose-dependent cytotoxicity for all formulations against lung cancer cells.... 

COVID-19 affects several human genes, each with its own p-value. The combination of drugs associated with these genes with small p-values may lead to an estimation of the combined p-value between COVID-19 and some drug combinations, thereby increasing the effectiveness of these combinations in defeating the disease. Based on human genes, we introduced a new machine learning method that offers an effective drug combination with low combined p-values between them and COVID-19. This study follows an improved approach to systematic reviews, called the Systematic Review and Artificial Intelligence Network Meta-Analysis (RAIN), registered within PROSPERO (CRD42021256797), in which, the PRISMA... 

Integral abutment bridges have many advantages over bridges with expansion joints in terms of economy and maintenance costs. However, in the design of abutments of integral bridges temperature loads play a crucial role. In addition, seismic loads are readily transferred to the substructure and affect the design of these components significantly. Currently, the European and American bridge design codes consider these two load cases separately in their recommended design load combinations. In this paper, the importance and necessity of combining the thermal and seismic loads is investigated for integral bridges. A 2D finite element combined pile-soil-structure interactive model is used in this... 

Background and Purpose: Shigella is a human shigellosis and its lipopolysaccharide is identified by 4TLR. The 4TLR is a family of pseudo-TOLL receptors and many immune routes are triggered by stimulating these receptors. Many studies show increasing of 4TLR expression in Mesenchyme stem cells under the influence of lipopolysaccharide. The main objective of this study was to identify the appropriate lipopolysaccharide of Shigella strains by stimulating the immune system for vaccine studies. Materials and Methods: In this experimental study, the stem cell of human Mesenchymal derived from bone marrow was treated by three dilution of 0.1, 0.01, and 0.001 extract of Shigella strains (Flexneri,... 

This experiment investigates the effects of utilizing Rahnama cultivar with high non-starchy polysaccharide content and supplementation of xylanase enzyme in poultry feed on the productivity features, nutrient digestibility and intestinal enzymes activity of 21-47 week laying hens. The experiment was conducted quite randomly and in factorial design that included eight treatments with 4 wheat levels (zero, 23, 46 and 69% that contained 1.8, 2.0, 2.2, 2.4% of xylose respectively) and two level enzymes (with and without enzyme) and 5 replications (6 hens) in each replication. During the experiment, by xylose level increase in diet, the weight (p > 0.05) and mass of the egg (p > 0.01) decreased...