University of Kashan

Abstract Chitin and chitosan are considerably versatile and promising biomaterials. The deacetylated chitin derivative chitosan is a useful and interesting bioactive polymer. Despite its biodegradability, it has many reactive amino side groups, which offer possibilities of chemical modifications, formation of a large variety of beneficial derivatives, which are commercially available or can be made available via graft reactions and ionic interactions. This study looks at the contemporary research in chitin and chitosan towards structure, properties, and applications in various industrial and biomedical fields.

In this article, the homotopy analysis method is applied to solve nonlinear fractional partial differential equations. On the basis of the homotopy analysis method, a scheme is developed to obtain the approximate solution of the fractional KdV, K(2,2), Burgers, BBM-Burgers, cubic Boussinesq, coupled KdV, and Boussinesq-like B(m,n) equations with initial conditions, which are introduced by replacing some integer-order time derivatives by fractional derivatives. The homotopy analysis method for partial differential equations of integer-order is directly extended to derive explicit and numerical solutions of the fractional partial differential equations. The solutions of the studied models are calculated in the form of convergent series with easily computable components. The results of applying this procedure to the studied cases show the high accuracy and efficiency of the new technique. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2010

Abstract Three sorbents were compared in order to determine their potential for oil spill cleanup. Polypropylene nonwoven web, rice hull, and bagasse with two different particle sizes were evaluated in terms of oil sorption capacities and oil recovery efficiencies. Polypropylene can sorb almost 7 to 9 times its weight from different oils. Bagasse, 18 to 45 mesh size, follows polypropylene as the second sorbent in oil spill cleanup. Bagasse, 14 to 18 mesh size, and rice hull have comparable oil sorption capacities, which are lower than those of the two former sorbents. It was found that oil viscosity plays an important role in oil sorption by sorbents. All adsorbents used in this work could remove the oil from the surface of the water preferentially.

Nanotechnology has finally and firmly entered the realm of drug delivery. Performances of intelligent drug delivery systems are continuously improved with the purpose to maximize therapeutic activity and to minimize undesirable side-effects. This review describes the advanced drug delivery systems based on micelles, polymeric nanoparticles, and dendrimers. Polymeric carbon nanotubes and many others demonstrate a broad variety of useful properties. This review emphasizes the main requirements for developing new nanotech-nology-based drug delivery systems.

Abstract Semiconductor heterogeneous photocatalysis has been received much attention from the scientific and researchers in the last decade. The combination of two semiconductors with various energy diagram can dramatically enhance the lifetime and separation of the charge carriers, restrain photogenerated electron‐hole recombination, and considerably enhance photocatalytic performance as compared with other single or binary components. In this regard, we introduced the Dy 2 BaCuO 5 /Ba 4 DyCu 3 O 9.09 nanocomposites as active photocatalysts below UV radiation. Dy 2 BaCuO 5 /Ba 4 DyCu 3 O 9.09 nanocomposites were prepared by a simple hydrothermal method and applied as a catalyst to treat water containing organic pollutions and microorganisms. Dy 2 BaCuO 5 /Ba 4 DyCu 3 O 9.09 nanocomposites degraded Methyl Orange (MO) about 87.0% after 120 min. In addition, these nanocomposites show antimicrobial activity against Gram‐positive species, including a pathogenic strain of Enterococcus faecalis , and Staphylococcus aureus , and a Gram‐negative species, including Klebsiella pneumonia and Escherichia coli .

Mapping flood-prone areas is a key activity in flood disaster management. In this paper, we propose a new flood susceptibility mapping technique. We employ new ensemble models based on bagging as a meta-classifier and K-Nearest Neighbor (KNN) coarse, cosine, cubic, and weighted base classifiers to spatially forecast flooding in the Haraz watershed in northern Iran. We identified flood-prone areas using data from Sentinel-1 sensor. We then selected 10 conditioning factors to spatially predict floods and assess their predictive power using the Relief Attribute Evaluation (RFAE) method. Model validation was performed using two statistical error indices and the area under the curve (AUC). Our results show that the Bagging–Cubic–KNN ensemble model outperformed other ensemble models. It decreased the overfitting and variance problems in the training dataset and enhanced the prediction accuracy of the Cubic–KNN model (AUC=0.660). We therefore recommend that the Bagging–Cubic–KNN model be more widely applied for the sustainable management of flood-prone areas.

/NiO nanocomposites were synthesized with sonication powers of 50 and 30 W, respectively. The agglomerated nanoparticles were obtained using different sonication powers, including 15, 30, and 50 W. The results showed that upon increasing the sonication power, the particle size decreased. After characterization, the optical, electrical, magnetic, and photocatalytic properties of the NC were studied. The nanocomposites showed an antiferromagnetic behavior. In this study, the photocatalytic degradations of two dyes, AR14 and AB92, were investigated in the presence of DBNO NC. Furthermore, the effects of the amount of photocatalyst, the concentration of the dye solution, the type of organic dye, and light irradiation on the photocatalytic activity of the nanocomposite were studied. The results showed that with an increasing amount of catalyst and decreasing concentration of dye, the photocatalytic activity of the nanocomposite was increased. This activity for the degradation of AR14 is higher than that of AB92. Both AR14 and AB92 dyes show higher photocatalytic degradation under UV irradiation than under Vis irradiation.

Nickel oxide (NiO) nanostructures have been prepared via a thermal decomposition method. Nanostructures were prepared by calcining β-Ni(OH)2 at various temperatures. H2(pnAA2), 1,3-propylenediamine, nickel nitrate, NaOH and acetyl acetonate were applied as starting reagents to fabricate the NiO nanostructures. The band gap was 2.83 eV, confirming the semi-conductive nature of the prepared NiO nanostructures and indicating its potential as a photocatalyst in effluent treatment. UV irradiation times, quantity of catalyst, pH and dye concentration were investigated by degrading Rhodamine B (RB, C28H31N2O3Cl) dye. These crucial factors indicated that the NiO nanostructures are an effective photocatalyst. Kinetic investigations of photodegradation revealed that the reactions followed the improved Langmuir–Hinshelwood model. The as-produced nanostructures were characterized using XRD, FESEM, FT-IR, UV-vis, VSM and BET.

In this work, two natural sources, including pomegranate peel extract and cochineal dye were employed for the synthesis of silver nanoparticles. The natural silver complex from pomegranate peel extract resulted in nano-sized structures through solution-phase method, but this method was not efficient for cochineal dye-silver precursor and the as-formed products were highly agglomerated. Therefore, an alternative facile solid-state approach was investigated as for both natural precursors and the results showed successful production of well-dispersed nanoparticles with narrow size distribution for cochineal dye-silver precursor. The products were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy dispersive X-ray microanalysis (EDX), and Transmission Electron Microscopy (TEM).

While methods of detecting outliers is frequently implemented by statisticians when analyzing univariate data, identifying outliers in multivariate data pose challenges that univariate data do not. In this paper, after short reviewing some tools for univariate outliers detection, the Mahalanobis distance, as a famous multivariate statistical distances, and its ability to detect multivariate outliers are discussed. As an application the univariate and multivariate outliers of a real data set has been detected using R software environment for statistical computing.

Abstract Proper medication dissolution must be ensured when developing or manufacturing a new solid dosage form. Quantitative analyses performed in dissolution or release tests become simpler when applying mathematical formulae which represent dissolution outcomes as a function of several dosage form properties. Methodologies utilized to examine the kinetics of drug release from controlled‐release formulations are reviewed. The analysis of variance was conducted using statistical, model‐independent, and ‐dependent techniques for the dissolution profile comparison and fitting, respectively. Model equations, including zero‐ and first‐order, Hixson‐Crowell, Weibull, Higuchi, Korsmeyer‐Peppas, Baker‐Lonsdale, Hopfenberg, etc., were employed to match the experimental data. Additional release parameters were taken to illustrate the drug release patterns. Using correlation factors and the Akaike information criterion (AIC), the best‐fitting model was discovered, as were the transport phenomena affecting the behavior of the recognized formulations.

The accurate determination of residual stresses has a crucial role in understanding the complex interactions between microstructure, mechanical state, mode(s) of failure, and structural integrity. Moreover, the residual stress management concept contributes to industrial applications, aiming to improve the product's service performance and life cycle. In this regard, the industry requests rapid, efficient, and modern methods to identify and control the residual stress state. This review article contains three main sections. The first section covers different residual stress determination methods and reports the advancements over the recent decade. The second section includes the role of residual stresses in the performance of a broad range of materials including metallic alloys, polymers, ceramics, composites, and biomaterials. This is presented by classifying different science areas dealing with residual stresses into two main groups, including “origins” and “effects” of residual stresses. The range of topics covered are “welding, machining, curing/cooling, and spray coating processes,” “medical and dental sciences,” and “fatigue and fracture mechanisms.” The third section summarizes various strategies to effectively control residual stresses through different manufacturing procedures. It is hoped that the data provided herein serves as a valuable up‐to‐date reference for engineers and scientists in the field of residual stress.

The present study is on the fabrication of new photocatalytic nanocomposites (Dy2O3-SiO2) employing a basic agent, tetraethylenepentamine (Tetrene), through a simple, efficient and, quick sonochemical approach. The features of the fabricated photocatalytic nanocomposite were examined employing a variety of microscopic and spectroscopic methods such as XRD, EDS, TEM, FTIR, DRS, and FESEM. The outcomes of morphological studies demonstrated that by proper tuning of sonication time and ultrasonic power (10 min and 400 W), a porous nanocomposite composed of sphere-shaped nanoparticles with a particle size in the range of 20 to 60 nm could be fabricated. The energy gap for the binary Dy2O3-SiO2 nanophotocatalyst was determined to be 3.41 eV, making these nanocomposite favorable for removing contaminants. The photocatalytic performance of the optimal nanocomposite sample was tested for photodecomposition of several contaminants including erythrosine, thymol blue, eriochrome black T, Acid Red 14, methyl orange, malachite green, and Rhodamine B. The binary Dy2O3-SiO2 nanophotocatalyst exhibited superior efficiency toward the decomposition of the studied contaminants. It was able to degrade the erythrosine pollutant more effectively (92.9%). Optimization studies for the photocatalytic decomposition of each contaminant demonstrated that the best performance could be achieved at a specific amount of contaminant and nanocatalyst. Trapping experiments illustrated that hydroxyl radicals were more effectively involved in the decomposition of contaminant molecules by Dy2O3-SiO2 nanophotocatalyst.

Mechanical, morphological, rheological, and crystallinity properties of pure polypropylene (PP)/glass fiber (GF) and PP/GF composites containing maleic anhydride polyolefin (POE-g-MA) at three different weight percentages (10, 20 and 30 wt%) were investigated. The test specimens were provided using 3D printing (FDM) and compression molding (CM) methods. Given brittleness and insufficient flexibility of the prepared filaments, POE-g-MA was used at different weight percentages, leading to enhanced filament flexibility. The test specimens were also provided using the CM method to compare the results with those of FDM method. Tensile tests were performed to evaluate mechanical properties of the specimens. Results showed that, addition of GF increased the modulus and strength of the composite while lowering its flexibility; on the other hand the composite exhibited decreased modulus and strength and increased flexibility upon adding the POE-g-MA. The specimens prepared via CM method exhibited higher values of strength and modulus, as compared to those prepared via 3D printing. Results of rheological studies further showed that the introduction of POE-g-MA tends to increase the storage modulus, loss modulus and viscosity, while lowering the value of tan δ. X-ray diffraction (XRD) analysis results indicated higher crystallinity of the specimens prepared via the CM method rather than 3D printing.

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper introduces an approach for the real-time extraction of the frequency, phase angle, and symmetrical components of the grid signal, which is of great importance for many applications in power systems such as power quality and protection. The proposed method is based on the concept of the adaptive notch filter that provides a fast and accurate estimation of the symmetrical components in the presence of frequency and amplitude variations. In addition, the system offers a high degree of immunity and insensitivity to power system disturbances, harmonics, and other types of pollutions that exist in the grid signal. The simplicity of the structure makes the method suitable for both software and hardware implementations. Moreover, this very simple and very powerful tool can be used as a synchronization technique, which further simplifies the control issues currently challenging the integration of distributed energy technologies into the electricity grid. Mathematical derivations are presented to describe the principles of operation, and experimental results confirm the validity of the analytical work. </para>

This paper reports the successful synthesis of various copper sulfide nanostructures via coprecipitation and hydrothermal routes using new starting reagents such as Na2SO3 as a reducing agent for converting Cu2+ to Cu+ and PMP dye–Cu(II) and carminic acid–Cu(II) complexes as new copper precursors for synthesizing quantum dots in aqueous medium. The as-synthesized products were extensively characterized by techniques including XRD, EDS, SEM, TEM, AFM, and DRS. Effects of different parameters such as temperature, surfactant, solvent, concentration, copper precursor, sulfide source, etc., on morphology and particle size of as-synthesized nanostructures were investigated. Moreover, the efficiency of various as-synthesized nanostructures in thin layer solar cells was evaluated. The results showed that particle size and morphology have a salient effect on solar cell efficiency. Also, utilizing prepared Cu2S quantum dots as a barrier layer in dye-sensitized solar cells (DSSCs) presented a remarkable increase in the efficiency of solar cells from 6.08% to 8.34% (∼37% improvement).

OBJECTIVE: This study was performed to determine the effects of probiotic supplementation on clinical and metabolic status of patients with rheumatoid arthritis (RA). METHODS: Sixty patients with RA aged 25-70 years were assigned into two groups to receive either probiotic capsules (n = 30) or placebo (n = 30) in this randomized, double-blind, placebo-controlled trial. The patients in the probiotic group received a daily capsule that contained three viable and freeze-dried strains: Lactobacillus acidophilus (2 × 10(9) colony-forming units [CFU]/g), Lactobacillus casei (2 × 10(9) CFU/g) and Bifidobacterium bifidum (2 × 10(9) CFU/g) for 8 weeks. The placebo group took capsules filled with cellulose for the same time period. Fasting blood samples were taken at the beginning and the end of the study to quantify related markers. RESULTS: After 8 weeks of intervention, compared with the placebo, probiotic supplementation resulted in improved Disease Activity Score of 28 joints (DAS-28) (-0.3 ± 0.4 vs. -0.1 ± 0.4, P = 0.01). In addition, a significant decrease in serum insulin levels (-2.0 ± 4.3 vs. +0.5 ± 4.9 μIU/mL, P = 0.03), homeostatic model assessment-B cell function (HOMA-B) (-7.5 ± 18.0 vs. +4.3 ± 25.0, P = 0.03) and serum high-sensitivity C-reactive protein (hs-CRP) concentrations (-6.66 ± 2.56 vs. +3.07 ± 5.53 mg/L, P < 0.001) following the supplementation of probiotics compared with the placebo. Subjects who received probiotic capsules experienced borderline statistically significant improvement in total- (P = 0.09) and low-density lipoprotein-cholesterol levels (P = 0.07) compared with the placebo. CONCLUSION: Overall, the results of this study indicated that taking probiotic supplements for 8 weeks among patients with RA had beneficial effects on DAS-28, insulin levels, HOMA-B and hs-CRP levels.

Scrophularia striata, commonly known as figwort, is one of the most important medicinal plants that mainly grows in cold regions of the Zagros Mountains (West of Iran). Although the chemical composition of this plant species has not yet been explored, people living in Ilam province (W Iran) have used it for many years to treat different illnesses. The present study aims to analyze the effect of some ecological factors on the antioxidant potential and the amount of phenol present in this plant species, using a random factorial design with two factors (elevation and region) and three replicates. The fruits of the plant were gathered from three different elevations. They were collected from three regions of the Ilam province (Badreh, Dareshahr, and Dehloran) in June 2016, when the fruits appear. Moreover, to analyze different soil chemical and physical features, soil samples were gathered from a depth of 0.5 m under the shrubs. The antioxidant action of the methanol extract from the plant samples and the total amount of phenol compounds were measured using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and the Folin-Ciocalteu method, respectively. The results showed that the effects of site and elevation, and the interaction between these factors, on the antioxidant potential and total phenol amount were significant with a probability of error of 1%. The maximum extract efficiency (19.37 ± 3.07%), antioxidant potential (126.5656 ± 0.96 µg/mL), and total amount of phenol (55.7689 ± 3.17 µg/mL) were obtained from Dareshahr at an elevation of 600 m above mean sea level. The minimum amount of total phenol (24.6544 ± 3.21 µg/ml) was recorded at the lowest elevation of Badreh, at which phosphorus, potassium, organic carbon, organic material, nitrogen, acidity, lime, and silt were present at the lowest amount. However, the antioxidant activity and total amount of phenol had a strong direct correlation in the two districts of Dareshahr and Badreh, but were reversely and strongly correlated in Dehloran. Therefore, it can be stated that Scrophularia striata has the potential for antioxidant activity, however, the complexity of the effect of ecological factors on one hand, and the emergence of different chemical processes in the plant under such effects on the other hand, has led to the synthesis of different compounds with antioxidant potential in the plant in different regions.

In this paper, fractional order PID (FOPID) controller was proposed for load frequency control (LFC) in an interconnected power system. This controller had five parameters to be tuned; thus, it provided two more degrees of freedom in comparison with the conventional PID. For proper tuning of the controller parameters, imperialist competitive algorithm (ICA) was used. ICA is a new evolutionary algorithm with proved efficiency. In this study, simulation investigations were carried out on a three-area power system with different generating units. These results showed that FOPID controller was robust to the parameter changes in the power system. Also, the simulation results certified much better performance of FOPID controller for LFC in comparison with conventional PID controllers.

Polymer-based materials are extensively used in various applications such as aircrafts, civilian structures, oil and gas platforms and electronics. They are, however, inherently damage prone and over time, the formation of cracks and microscopic damages influences the thermo-mechanical and electrical properties, which eventually results in the total failure of the materials. This paper provides an overview of the principal causes of cracking in polymer and composites and summarizes the recent progress in the development of non-destructive techniques in crack detection. Furthermore, recent progress in the development of bio-inspired self-healing methods in autonomic repair is discussed.