Abstract
Encapsulation of bioactive compounds (e.g., phenolic acids) into nanoparticles is a well-received technique in the searching for new antimicrobial agents against multidrug-resistant pathogens. Encapsulation can be a good technique to maintain the stability of phenolic acids against environmental conditions. In this study, 3-hydroxyphenylacetic acid (3-HPAA) was encapsulated into alginate-chitosan nanoparticles with the ion gelation technique. The characterization of loaded and unloaded nanoparticles was performed via dynamic light scattering, Fourier transform infrared spectroscopy, and scanning electron microscopy. According to the results, 3-HPAA loaded nanoparticles have spherical shapes with a diameter range of 40-80 nm and an average hydrodynamic diameter of 361.0 +_ 69.8 nm. The loading of 3-HPAA was successfully achieved based on the Fourier transform infrared spectra and encapsulation percentage studies. The antimicrobial effect of the nanoparticles in solution forms was tested on P. aeruginosa, S. epidermidis, MRSA, and MSSA. The results demonstrated that the 3-HPAA loaded alginate chitosan nanoparticle solution showed elevated antimicrobial effect due to the pH change by treatment with 1% acetic acid, and it displayed bacteriocidal effects in a strain-specific and dose-dependent manner. Therefore, the 3-HPAA loaded alginate chitosan nanoparticle solution was produced successfully with the bacteriocidal effect against serious pathogenic bacteria.
Abstract
The small scale impact on the vibrational properties of "unctionally graded" (FG) nanoplate embedded in an elastic medium is examined. The formulation is based on the four-unknown refined integral plate theory on aggregate with the nonlocal elasticity theory. Contrary to other theories, this one involves only four unknown variables. The solution procedure is obtained by employing the motion differential equations of physical phase that are converted into set of "linear algebraic equations". After, these are solved by a computer code. The influences of aspect ratio, material index, nonlocal parameter and elastic medium stiffness on the different modal vibrations of FG nanoplate are explored. The results demonstrate the significant impact of different physical and geometrical parameters on the vibration behavior of FG nanoplate.
Key Words
elastic medium; FG nanoplate; four-unknown refined integral plate theory; nonlocal theory; vibration
Address
Halima Bouafia, Abdelmoumen Anis Bousahla and Houari Heireche: Laboratoire de Modélisation et Simulation Multi-échelle, Université de Sidi Bel Abbés, Algeria
Abdelbaki Chikh: Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Civil Engineering Department, Algeria/ Université Ibn Khaldoun, BP 78 Zaaroura, 14000 Tiaret, Algérie
Fouad Bourada: Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Civil Engineering Department, Algeria/ Département des Sciences et de la Technologie, Université de Tissemsilt, BP 38004 Ben Hamouda, Algérie
Abdeldjebbar Tounsi and Kouider Halim Benrahou: Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Civil Engineering Department, Algeria
Abdelouahed Tounsi: Material and Hydrology Laboratory, University of Sidi Bel Abbes, Faculty of Technology, Civil Engineering Department, Algeria/ YFL (Yonsei Frontier Lab), Yonsei University, Seoul, Korea/ Civil and Environmental Engineering Department, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia
Mesfer Mohammad Al-Zahrani: Civil and Environmental Engineering Department, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia
Muzamal Hussain: Department of Mathematics, Govt. College University Faisalabad, 38000, Faisalabad, Pakistan
Abstract
The effect of thermal stresses on the torsional vibration of non, single, and double-cracked nanorods surrounded by an elastic medium is investigated. The differential constitutive relation of the nonlocal theory is applied to the motion equation. Three-dimensional linear thermal strains raised from the thermal stresses are derived using nonlinear Green's strains. The surrounding elastic medium acts as infinite torsional springs. The crack is modeled as a rotational spring. Using Hamilton's principle, the motion equation is obtained. Effect of the crack position and severity, number of cracks, high and low temperatures, nonlocal coefficient, elastic medium stiffness, and nanorod length are examined. The temperature effect on the frequencies depends on the values of the crack parameters, crack numbers, elastic medium stiffness, and nanorod length, and it is independent of the nonlocal scale coefficient. The crack leads to a decrease in the frequencies at any temperature. The elastic medium causes an increase in the frequencies at any temperature.
Key Words
crack; elastic medium; thermal stresses; torsional vibration
Address
Sardar S. Abdullah: School of Mechanical Engineering, Iran University of Science and Technology, Narmak, Tehran, 11369, Iran/ Mechanical Department, College of Engineering, Salahaddin University-Erbil, Erbil, 44001, Iraq
Shahrokh H. Hashemi: School of Mechanical Engineering, Iran University of Science and Technology, Narmak, Tehran, 11369, Iran/ Center of Excellence in Railway Transportation, Iran University of Science and Technology, Narmak, 11369, Tehran, Iran
Nazhad A. Hussein: Mechanical Department, College of Engineering, Salahaddin University-Erbil, Erbil, 44001, Iraq
Reza Nazemnezhad: School of Engineering, Damghan University, Damghan, Islamic Republic of Iran
Abstract
MXene (Ti3C2Tx) reinforced copper matrix composites with weight fractions of MXene from 1 to 4 wt.% were fabricated based on molecular-level and high-shear mixings and spark plasma sintering (SPS) method. The mechanical properties of the composites with different weight fractions of MXene were studied, and X-ray photoelectron spectroscopy (XPS) was used to track the state of MXene in the composite preparation process. Chemical state and interface transitions would result in an interesting ductile-brittle transition phenomenon of the composite. The Vickers hardness and compressive strength of the composites prepared by the molecular-level mixing and high-shear mixing methods have been improved (the maxima are 44.9% and 41.8%, respectively), where the addition of 1wt.% MXene results in a tensile strength increase of 29.9%. The results show that molecular-level mixing and high-shear mixing methods are hopeful to be applied to produce many kinds of MXene composites.
Key Words
copper-based composites; mechanical properties; molecular-level and high-shear mixings; MXene Ti3C2Tx
Address
Lu Liu, Guobing Ying, Cong Hu, Chen Zhang and Cheng Wang: Department of Materials Science and Engineering, College of Mechanics and Materials, Hohai University, Nanjing, 211100, China
Dong Wen: Key Laboratory of Superlight Materials & Surface Technology (Harbin Engineering University), Ministry of Education, Harbin 150001, China
Abstract
Precipitation is one of the most significant variables with an impact on the environment, agriculture, as well as the design of any hydraulic infrastructures. The rainfall analysis predicts the highest, average, and minimal values of rainfall that are expected in certain catchments for return periods. The long-term variability of rainfall over the Arbaat watershed was studied at the various stations in a duration (day, month, and year) from 1942 to 2010 rainfall runoff using the Isohyetal Map of the area besides using different plotting position formulae of rainfall ratios. This statistical analysis will offer valuable data for water resource planners for Port Sudan, farmers, and Red Sea Water Corporations engineers (RSSWC) to evaluate the availability of water and create the storage accordingly. From the rainfall-depth analysis outcomes, the rainfall pattern was found to be irregular. Although the historical data was used, the meteorological observation of Suakin, Sinkat, and Arbaat stations was stopped from work. However, Port Sudan station gave reliable results without resorting to precipitation data measured by the satellites. Besides, the outcomes of this study can provide rational guidelines and policy concerning water resources to preserve the health of several ecosystems in the regions of under study.
Key Words
annual rainfall; khor Arbaat; long-term rainfall analysis; monthly rainfall; Red Sea
Address
Ali Aldrees and Abdulaziz Alqahtani: Prince Sattam bin Abdulaziz University, College of Engineering, Department of Civil Engineering, Alkharj, 16273, Saudi Arabia
Abubakr Taha Bakheit Taha: Prince Sattam bin Abdulaziz University, College of Engineering, Department of Civil Engineering, Alkharj, 16273, Saudi Arabia/ Department of Civil Engineering, Faculty of Engineering, Red Sea University, Port Sudan, Sudan
Gasim Hayder: Department of Civil Engineering, College of Engineering, Universiti Tenaga Nasional (UNITEN), 43000 Kajang, Selangor Darul Ehsan, Malaysia
Abstract
Taking into account the decreased number of available lands, the construction of structures on soft soil leads towards the development of soil stabilizing models. This study is aimed at studying the decrement of land resources available, and the design of civil engineering structures on soft soils that will develop the soil impact of nano-SiO2 in the use of clay soil with low liquid limit, in particular shear resistance and unconfined compression. A novel nano-soil stabilizer has been created in this investigation by use of nano-SiO2 activity and ultrafine features that have enabled cement-based stabilizers to increase their characteristics in broad application possibilities. This research aims to examine the influence on soil engineering, particularly the shear strength of clay soil with a low liquid limit to the effect of adding nano-SiO2. Nano-SiO2 has 3 different percentages combined with soil (i.e., 0.5, 0.7 percent by weight of the parent soil), A direct shear test was used to evaluate the shear strength of the specimen, and then the results were analyzed by Artificial Neural Network (ANN) to increase the accuracy of outcomes. Increased nano-SiO2 concentration was shown to lead to an increased internal friction angle and cohesiveness on clay soil. The optimal content for nano-SiO2 is 0.7%. ANN could accurately demonstrate the shear strength percentages in nano-SiO2 content.
Address
Qiao Yanzhen: School of Mines, Hulunbuir University, Hailar, Inner Mongolia, 021000, China
Yousef Zandi and Abouzar Rahimi: Department of Civil Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran
Sara Pourkhorshidi: Civil Engineering Department, Sahand University of Technology, Tabriz, Iran
Angel Roco-Videla: Programa Magister en Ciencias Químico-biológicas. Facultad de Ciencias de la Salud. Universidad Bernardo O'Higgins, Santiago, Chile/ Departamento de Ingeniería Civil, Facultad de Ingeniería. Universidad Católica de la Santísima Concepción, Concepción, Chile
Mohamed Amin Khadimallah: Prince Sattam Bin Abdulaziz University,College of Engineering,Civil Engineering Department,Al-Kharj,16273,Saudi Arabia/ Laboratory of Systems and Applied Mechanics,Polytechnic School of Tunisia,University of Carthage,Tunis,Tunisia
Mohammed Jameel: Department of Civil Engineering, College of Engineering, King Khalid University, Abha, Saudi Arabia
Ehsan Kasehchi: Department of Civil Engineering Roudehen Branch Islamic Azad University Roudehen Iran
Hamid Assilzadeh: Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam
Abstract
The rotor disk produces an azimuthal velocity component in the space between the rotor and stator of a turbine disk, also known as the rim seal cavity. As part of an empirically study, the rim seal cavity is subjected to a test aimed to count the number of unstable structures and evaluate their rotational speed. An Electronic Control Unit (ECU) has a leak test aperture that is sealed by a sealing device that is selectively disposed in the leak test aperture. Designing pump and compressor machines and units requires the development of dependable seal assemblies that maintain tightness over a long period of time and in a wide variety of pressures and temperature. In the field of electrochemical machining (ECM), heat-resistant and high-strength materials may be machined into complicated forms using this well-known technology. ECM presents some issues as the electrochemical copying of grooves, insulating groove features, slots and mini-holes can cause water leakage due to the poor sealing device of the closed integral structure turbine disk. Sealing devices of rotor turbine disks are heavy components with low-cycle fatigue analysis to their life curves. However, there is rare analysis to detect their defects in various rotor regions (temperature, considering stress, mission profile). This study by use of hydro-thermal loading has attempted to focus on the mechanical seals rings and basic productive and operating requirements. Taking the damage and wear, the clearance has been altered that cause a raising in leakage. Generally, the leakage grows more rapidly than linearly with the after-damage clearance. Also, damage and wear were related to the labyrinth seal itself, resulting that the bending curvature and the percentage of bent tooth length were also relevant in defining the leakage in the case of bending damage.
Key Words
ECM; hydro-thermal loading; sealing device; soft computing; turbine disk
Address
Yan Cao, Qingming Fan, Yu Bai, Junde Guo and Leijie Fu: School of Mechatronic Engineering, Xi'an, 710021 China
Yousef Zandi and Abouzar Rahimi: Department of Civil Engineering,Tabriz Branch, Islamic Azad University, Tabriz, Iran
Mohamed Amine Khadimallah: Prince Sattam Bin Abdulaziz University, College of Engineering, Civil Engineering Department, Al-Kharj, 16273, Saudi Arabia/ Laboratory of Systems and Applied Mechanics, Polytechnic School of Tunisia, University of Carthage, Tunis, Tunisia
Mohammed Jameel: Department of Civil Engineering, College of Engineering, King Khalid University, Abha, Saudi Arabia
Hamid Assilzadeh: Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam
Abstract
This paper investigates impact of thickness stretching phenomenon on the scale-dependent behavior of nano panel in electromagnetic environment in the framework of HOSNDT. Unlike classic theories of shells and plates, the radial displacement is assumed variable along the thickness direction as summation of bending, shear and thickness stretching displacements in which the last term is assumed trigonometrically variable along the thickness direction. Generalized magneto-electro-elastic equations are derived using the virtual work principle. The main novelty of the present paper is application of thickness stretching formulation on the results. The bending results are calculated using analytical method with actuating the nano panel with initial electromagnetic potentials. An extended numerical investigation is presented to examine influence of significant parameters on the static results.
Key Words
electromagnetic potentials; higher-order shear and normal deformation theory; panel; scale-dependent theory; thickness-stretching effect
Address
Allam Maalla: School of Engineering, Guangzhou College of Technology and business, Guangzhou 510850, Guangdong, China
Jun Song: School of Civil Engineering, Shandong Jiaotong University, Jinan, 250357, Shandong, PR China
