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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Health Literacy
- نوع مقاله: Journal Article
- کلمات کلیدی: cancer,participation,Treatment decision making
- چکیده:
- چکیده انگلیسی: Background and objective: Cancer is one of the most common diseases and the second reason of death in Iran. Giving decision making authority to patients is one of the fundamental principles of the protection of patients. Patients have rights as consumers of health care services that nurses, physician and other health professionals are responsible for maintaining and protecting it. This study aimed to determine cancer patients’ involvement in treatment decisions making.
Methods:This cross-sectional study was carried out as descriptive-analytic with practical purpose in 2017 in Zahedan University of Medical Sciences. The study population included 1,000 patients who had cancer that whom 450 patients were selected by simple random sampling. To measure patient participation in treatment decisions, was used of Levente Kristona standard questionnaire. Reliability and validity of the questionnaire was confirmed (coefficient = 0.82). For data analysis used of software spss21 with descriptive statistics and chi-square tests
Results: among the patients, 197 men (53%) and 177 women (47%) with a mean age of 31 years were examined. The results of this study showed that the score of mean participation in treatment decisions among the cancer patients was 30 ± 12 and it was in low level. The patients’ participation in treatment decisions had a significant relationship with education level (P = 0.027), however, it was not statistical significant with gender, age, income, occupation and type of cancer and other demographic variables (P> 0.05).
Conclusion: In general, that patients' participation in clinical decision making is weak and low. Since patients’ participation in clinical decisions could affect the quality of treatment decisions, therefore, health care providers should attention more to this fact. Also, culturalizating and education according to patients’ knowledge and use of treatment techniques are recommended for clinical decision making promotion.
Paper Type:Research Article.- انتشار مقاله: 20-06-1395
- نویسندگان: Mohammad Khammarnia,Monir Eskandari,Arezo Alinezhade Ranjbar,Alireza Ansari-Moghadam,Mostafa Peyvand
- مشاهده
- جایگاه : پژوهشی
- مجله: Interdisciplinary Journal of Virtual Learning in Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Students,nursing,Team-Based Learning,Learning Objectives,Merrill’s First Principles of Instruction
- چکیده:
- چکیده انگلیسی: Introduction Team-based learning is one of the methods concerned in medical education. Teaching and learning have some principles known as Merrill’s first principles that are a basis for effective education. This study examined the effect of using team-based learning combined with Merrill’s Principles on achieving learning objectives in nursing students. Methods This was a semi-experimental, applied research that used pretest-posttest design with a control group. The statistical population included all undergraduate students of Ardebil University of Medical Sciences, Meshkin Shahr campus, in 2015 - 2016. The sample group comprised a class of nursing students selected by convenience sampling method (n = 47). The subjects were divided into two groups of control (n = 23) and test (n = 24) using simple random allocation. A pretest was given to both groups prior to the implementation of the training. Then, the intended plan was executed for 5 weeks and at the end, a posttest was administered. The data were analyzed by applying covariance analysis test using SPSS version 20. Results The results showed that the learning objectives scores in the test group increased from 2.68 and 1.31 to 17.83 and 12.16 for remembrance and application levels, respectively, while the increments were not significant in the control group. In other words, there was a significant difference in the achievement of learning objectives between the test and control groups (P < 0.001), implying that the test group had better learning. Conclusions By using team-based learning combined with Merrill’s First Principles, we can improve learning objectives achievements.
- انتشار مقاله: 11-10-1348
- نویسندگان: Mehdi Badali,Sadaf Alizadeh Derakhshi,Parisa Bagheri,Mohammad Reza Ansari
- مشاهده
- جایگاه : پژوهشی
- مجله: Challenges in Nano and Micro Scale Science and Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Nanocomposite,Random Distribution,Interphase,Micromechanics,Thermo-mechanical properties
- چکیده:
- چکیده انگلیسی: A three-dimensional micromechanics-based analytical model is developed to study thermo-mechanical properties of polymer composites reinforced with randomly distributed silica nanoparticles. Two important factors in nanocomposites modeling using micromechanical models are nanoparticle arrangement in matrix and interphase effects. In order to study these cases, representative volume element (RVE) of nanocomposites is extended to c×r×h nano-cells in three dimensions and consists of three phases including nanoparticles, polymer matrix and interphase between the nanoparticles and matrix. Nanoparticles are surrounded by the interphase in all composites. Effects of volume fraction, aspect ratio and size of nanoparticle on the effective thermo-mechanical response of the nanocomposite are studied. Also, the effects of polymer matrix properties and interphase including its elastic modulus and thickness are theoretically investigated in detail. It is revealed that when nanoparticles are randomly distributed in the matrix and interphase effects are considered, the results of present micromechanical model are in very good agreement with experimental data.
- انتشار مقاله: 01-03-1394
- نویسندگان: Reza Ansari,Mohammad Kazem Hassanzadeh Aghdam
- مشاهده
- جایگاه : پژوهشی
- مجله: Challenges in Nano and Micro Scale Science and Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Graphene sheet,Elastic properties,Agglomeration,Micromechanics,Metal matrix nanocomposite
- چکیده:
- چکیده انگلیسی: The purpose of the present work is to analyze the modulus of elasticity of graphene (Gr) sheet-reinforced metal matrix nanocomposites (MMNCs) using a homogenized model based on the Mori-Tanaka micromechanics approach. The main focus is to investigate the effects of Gr sheet agglomeration on the MMNC macroscopic elastic modulus. Also, the role of aligning Gr sheets in the mechanical performance of MMNC is explored. It is found that a small amount of Gr sheets can increase the elastic properties of the MMNCs. Addition of 5% by volume fraction of Gr sheet in an aluminum (Al) matrix improves the MMNC elastic modulus by 31%. The mechanical properties of MMNCs are very sensitive to the Gr sheet agglomeration. Formation of sheet agglomeration can significantly decrease the MMNC elastic modulus. It is observed that the Gr sheet alignment plays a superior role in enhancing the MMNC elastic properties. Generally, alignment of Gr sheets leads to the maximum level of MMNC mechanical properties in axial direction. As compared to the uniform dispersion type, aligning the 5 vol% Gr sheets can improve the elastic of Al nanocomposite by as much as 20%. The elastic modulus calculated from the present micromechanical model for different types of MMNCs is compared with available experimental data. In addition, the results from the Mori-Tanaka method are also compared with other analytical results acquired from semi-empirical Halpin-Tsai (H-T) model and the rule of mixture (ROM).
- انتشار مقاله: 05-12-1398
- نویسندگان: Roozbeh Pouyanmehr,Reza Ansari,Mohammad Kazem Hassanzadeh-Aghdam
- مشاهده
- جایگاه : پژوهشی
- مجله: Mechanics of Advanced Composite Structures
- نوع مقاله: Journal Article
- کلمات کلیدی: Impact properties,Glass/epoxy composites,Fiber metal laminates (FMLs),Hygrothermal aging,Flexural properties
- چکیده:
- چکیده انگلیسی: In this article, the effect of hygrothermal aging on mechanical properties of fiber metal laminates (FMLs) and E-glass/epoxy (GE) composites is investigated. First, FML and GE specimens were built using wet lay-up technique under vacuum pressure. Hygrothermal aging simulation was then carried out on both specimen types in distilled water at a constant temperature of 90 °C for 5 weeks. The resulting behavior of degradation for both types of specimens caused by hygrothermal aging was evaluated by bending and Charpy impact testing. As expected, because of the protective role of aluminum layers, FML specimens showed remarkably lower water absorption after hygrothermal aging compared to the glass/epoxy composites. Experimental results also revealed that the flexural properties of both the FML and GE laminates were affected by the hygrothermal aging, whereas a lower level of deterioration in impact strength was found.
- انتشار مقاله: 02-08-1395
- نویسندگان: Moslem Najafi,Reza Ansari,Abolfazl Darvizeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Mechanics of Advanced Composite Structures
- نوع مقاله: Journal Article
- کلمات کلیدی: Impact properties,Glass/epoxy composites,Fiber metal laminates (FMLs),Flexural properties,Iso-thermal aging
- چکیده:
- چکیده انگلیسی: The aim of this study is to investigate effects of isothermal aging on mechanical properties of fiber metal laminates (FMLs) and glass/epoxy composites. For this purpose, both materials were fabricated using the wet lay-up manufacturing technique under vacuum pressure. Both the glass/epoxy composites and the FML specimens were then subjected to isothermal aging (130°C, dried air) for up to 5 weeks. After the isothermal aging, the specimens’ weight loss, caused by thermo-oxidative conditioning, was evaluated. Bending and Charpy impact tests were conducted on both the unaged and aged specimens to examine the isothermal conditioning’s effect on the mechanical properties of studied materials. Experimental results revealed that isothermal aging severely affected impact strength in the form of embrittlement and reduced ductility. However, no significant reduction was found in the flexural stiffness of isothermally aged FML and glass/epoxy specimens.
- انتشار مقاله: 02-08-1395
- نویسندگان: Moslem Najafi,Reza Ansari,Abolfazl Darvizeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Ultrafine Grained and Nanostructured Materials
- نوع مقاله: Journal Article
- کلمات کلیدی: Nonlinear Vibration,Piezoelectric microcantilever,Atomic-force microscopy,Fluid-solid interaction analysis
- چکیده:
- چکیده انگلیسی: Nowadays, atomic-force microscopy plays a significant role in nanoscience and nanotechnology, and is widely used for direct measurement at atomic scale and scanning the sample surfaces. In tapping mode, the microcantilever of atomic-force microscope is excited at resonance frequency. Therefore, it is important to study its resonance. Moreover, atomic-force microscopes can be operated in fluid environments such as their applications in chemical and biological sensors. Additionally, piezoelectric microcantilevers are used to enhance atomic-force microscope scanning. Motivated by these considerations, presented herein is a finite element investigation into the nonlinear vibration behavior of piezoelectric microcantilever of atomic-force microscopes in fluid environment. For this purpose, a 3D finite element model coupled with a computational fluid dynamics model is introduced based upon a fluid-solid interaction analysis. First, the reliability of present fluid-solid interaction analysis is revealed by comparison with experimental data available in the literature. Then, numerical results are presented to study the influences of fluid dynamic viscosity and density on the resonance frequency, resonance amplitude and time response of piezoelectric microcantilever. It was shown that increasing the fluid density and dynamic viscosity results in the decrease of resonance frequency. For example, for density equal to 1000 kg/m3 , increasing the viscosity of fluid environment from 0.1 to 1, 10 and 20 mPa.s leads to decrease of resonance frequency about 3%, 29% and 42%, respectively. Also, the resonance amplitude of microcantilever increases as the density increases, while increasing dynamic viscosity has a decreasing effect on the resonance amplitude.
- انتشار مقاله: 20-03-1396
- نویسندگان: Masoud Ahmadi,Reza Ansari,Mansour Darvizeh,Hessam Rouhi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Ultrafine Grained and Nanostructured Materials
- نوع مقاله: Journal Article
- کلمات کلیدی: Carbon Nanotube,Elastic properties,Multiscale modeling,Higher-order Cauchy-Born rule,Finite deformation
- چکیده:
- چکیده انگلیسی: This paper deals with the calculation of the elastic properties for single-walled carbon nanotubes (SWCNTs) under axial deformation and hydrostatic pressure using the atomistic-based continuum approach and the deformation mapping technique. A hyperelastic model based on the higher-order Cauchy-Born (HCB) rule being applicable at finite strains and accounting for the chirality and material nonlinearity is presented. Mechanical properties of several carbon nanotubes (CNTs) are computed and compared with the existing theoretical results and a good agreement is observed. Moreover, by comparison with atomistic calculations, it is found that the present model can reproduce the energetics of axially deformed CNTs. The model is then adopted to study the dependence of the elastic properties on chirality, radius and strain which yields an upper bound on the stability limit of axially and circumferentially stretched nanotubes. The influence of chirality is found to be more prominent for smaller tubes and as the diameter increases, the anisotropy induced by finite deformations gets nullified. It is discerned that the constitutive properties of the CNT can vary with deformation in a nonlinear manner. It is also found that the CNT displays a martial softening behavior at finite tensile strains and a hardening behavior at slightly compressive strains.
- انتشار مقاله: 10-12-1395
- نویسندگان: Abolfazl Shahabodini,Reza Ansari,Mansour Darvizeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Ultrafine Grained and Nanostructured Materials
- نوع مقاله: Journal Article
- کلمات کلیدی: Density functional theory,Nanostructure,Elastic properties,Porous graphene
- چکیده:
- چکیده انگلیسی: Importance of covalent bonded two-dimensional monolayer nanostructures and also hydrocarbons is undeniably responsible for creation of new fascinating materials like polyphenylene polymer, a hydrocarbon super honeycomb network, so-called porous graphene. The mechanical properties of porous graphene such as its Young’s modulus, Poisson’s ratio and the bulk modulus as the determinative properties are calculated in this paper using ab initio calculations. To accomplish this aim, the density functional theory on the basis of generalized gradient approximation and the Perdew–Burke–Ernzerhof exchange correlation is employed. Density functional theory calculations are used to calculate strain energy of porous graphene with respect to applied strain. Selected numerical results are then presented to study the properties of porous graphene. Comparisons are made between the properties of porous graphene and those of other analogous nanostructures. The results demonstrated lower stiffness of porous graphene than those of graphene and graphyne, and higher stiffness than that of graphdyine and other graphyne families. Unlikely, Poisson’s ratio is observed to be more than that of graphene and also less than that of graphyne. It is further observed that the presence of porosity and also formation of C-H bond in the pore sites is responsible for these discrepancies. Porous graphene is found to behave as the isotropic material.
- انتشار مقاله: 29-10-1394
- نویسندگان: Reza Ansari,Shahram Ajori,Sina Malakpour
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Ultrafine Grained and Nanostructured Materials
- نوع مقاله: Journal Article
- کلمات کلیدی: Natural frequency,Surface effect,Nanoshell,Exact Method
- چکیده:
- چکیده انگلیسی: It has been revealed that the surface stress effect plays an important role in the mechanical behavior of
structures (such as bending, buckling and vibration) when their dimensions are on the order of
nanometer. In addition, recent advances in nanotechnology have proposed several applications for
nanoscale shells in different fields. Hence, in the present article, within the framework of surface
elasticity theory, the free vibration behavior of simply-supported cylindrical nanoshells with the
consideration of the aforementioned effect is studied using an exact solution method. To this end, first,
the governing equations of motion and boundary conditions are obtained by an energy-based
approach. The surface stress influence is incorporated into the formulation according to the Gurtin-
Murdoch theory. The nanoshell is modeled according to the first-order shear deformation shell theory.
After that, the free vibration problem is solved through an exact solution approach. To this end, the
dimensionless form of governing equations is derived and then solved under the simply-supported
boundary conditions using a Navier-type solution method. Selected numerical results are presented
about the effects of surface stress and surface material properties on the natural frequencies of
nanoshells with different radii and lengths. The results show that the surface energies significantly
affect the vibrational behavior of nanoshells with small magnitudes of thickness. Also, it is indicated
that the natural frequency of the nanoshell is dependent of the surface material properties.- انتشار مقاله: 16-07-1394
- نویسندگان: Hessam Rouhi,Reza Ansari,Mansour Darvizeh
- مشاهده