فهرست مقالات continuum

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  1 - Computational Design and Synthesis of Molecular Imprinted Polymers for solid-phase Extraction of Acyclovir
  gholamali haghdoost
  10.30495/jptc.2023.70690.1246
  Highly selective molecularly imprinted polymers (MIPs) for solid-phase extraction of acyclovir have been designed and prepared. In order to study the intermolecular interactions in the pre-polymerization mixture and to find a suitable functional monomer in MIP preparati چکیده کامل

  Highly selective molecularly imprinted polymers (MIPs) for solid-phase extraction of acyclovir have been designed and prepared. In order to study the intermolecular interactions in the pre-polymerization mixture and to find a suitable functional monomer in MIP preparation, a computational approach was developed. It was based on the comparison of the binding energy of the complexes between the template and functional monomers. The effect of the polymerization solvent was included using the polarizable continuum model. According to the theoretical calculation results, the MIP with acyclovir as template was prepared by precipitation polymerization method using acrylamide (AAM) as functional monomer and ethylene glycol dimethacrylate (EGDMA), as cross-linker in acetone. Having confirmed the results of computational method, three MIPs were synthesized with different functional monomers, i.e. acrylamide (AAM), allylamine (AA) and acrylonitrile (ACN), and then evaluated using LangmuirFreundlich (LF) isotherm. The results of this study have indicated the possibility of using computer aided design for rational selection of functional monomers and solvents capable of removal of acyclovir from contaminated fluids. پرونده مقاله
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  2 - اشتقاق و اعتبارسنجی توابع انتقالی طیفی پارامتریک به‌منظور برآورد ویژگی‌های هیدرولیکی خاک در گستره VIS-NIR-SWIR
  ابراهیم بابائیان مهدی همایی علی اکبر نوروزی
  ویژگی‌های هیدرولیکی خاک اهمیت زیادی در چرخۀ آبی طبیعت دارند. هدف از انجام این پژوهش، امکان‌سنجی استفاده از اطلاعات طیفی خاک در گستره مرئی، مادون قرمز نزدیک و میانی (2500-350 نانومتر) به‌منظور برآورد پارامتریک ویژگی‌های هیدرولیکی خاک بود. بدین منظور، بازتاب ابرطیفی نمونه چکیده کامل

  ویژگی‌های هیدرولیکی خاک اهمیت زیادی در چرخۀ آبی طبیعت دارند. هدف از انجام این پژوهش، امکان‌سنجی استفاده از اطلاعات طیفی خاک در گستره مرئی، مادون قرمز نزدیک و میانی (2500-350 نانومتر) به‌منظور برآورد پارامتریک ویژگی‌های هیدرولیکی خاک بود. بدین منظور، بازتاب ابرطیفی نمونه‌های خاک با استفاده از دستگاه اسپکترورادیومتر و به کمک روش‌های استاندارد اندازه‌گیری شد. پس از انجام پیش‌پردازش‌های طیفی، همبستگی بین مقادیر بازتاب در هر یک از طول موج‌های منحنی‌های حذف پیوستار طیفی با پارامترهای هیدرولیکی مدل معلم- ون‌گنوختن ( ، n و Ks*) مورد بررسی قرار گرفت. سپس با استفاده از روش رگرسیون مرحله‌ای چندگانه، روابط ریاضی مربوطه پی‌ریزی و تحت عنوان توابع انتقالی طیفی پارامتریک (PSTFs) نامگذاری شدند. بر اساس نتایج، بیشترین ضریب همبستگی بین متغیرها در طول موج‌های نزدیک به 550 و 2300 نانومتر (برای پارامترهای و n ) و 1927 نانومتر (برای پارامتر Ks*) به‌دست آمد. توابع انتقالی طیفی دقت تقریباً یکسانی در برآورد پارامترهای (54/0=R) و n(58/0=R) نشان دادند. در حالی‌که این توابع، بهترین تخمین‌ها را برای پارامتر Ks*با ضریب همبستگی (R) برابر با 76/0 نشان دادند. با استفاده از توابع انتقالی طیفی، مقدار رطوبت خاک به ازای تمامی پتانسیل‌های ماتریک با متوسط RMSE برابر cm3 cm-3 017/0 برآورد شد. بر اساس نتایج این پژوهش، اگرچه پارامترهای هیدرولیکی تخمینی با دقت بسیار بالایی همراه نبودند، لیکن این رویکرد ضمن آن‌که می‌تواند به عنوان کاربرد نوینی از طیف‌سنجی خاک مطرح شود، می‌تواند به عنوان روشی غیرمستقیم برای برآورد پارامتریک ویژگی‌های هیدرولیکی خاک نیز معرفی شود. پرونده مقاله
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  3 - ارزیابی توابع انتقالی طیفی و توابع انتقالی خاک در پیش‌بینی نگهداشت آب در خاک
  ابراهیم بابائیان مهدی همایی علی اکبر نوروزی
  ویژگی‌های هیدرولیکی خاک اثری مهم بر جریان آب، انتقال املاح و گازها در محیط خاک داشته و اهمیتی بسیاردرمطالعات هیدرولوژیک دارند. اگرچه اخیراً اطلاعات طیفی خاک در گستره مرئی، مادون قرمز نزدیک و میانی به عنوان روشی کم هزینه، سریع و غیرمخرب در تخمین ویژگی‌های مبنایی خاک مورد چکیده کامل

  ویژگی‌های هیدرولیکی خاک اثری مهم بر جریان آب، انتقال املاح و گازها در محیط خاک داشته و اهمیتی بسیاردرمطالعات هیدرولوژیک دارند. اگرچه اخیراً اطلاعات طیفی خاک در گستره مرئی، مادون قرمز نزدیک و میانی به عنوان روشی کم هزینه، سریع و غیرمخرب در تخمین ویژگی‌های مبنایی خاک مورد استفاده قرار گرفته، لیکن مطالعات بسیار اندکی در مورد برآورد ویژگی‌های هیدرولیکی خاک به کمک داده‌های طیفی خاک صورت گرفته است. هدف از این پژوهش، ارزیابی عملکرد داده‌های طیفی خاک در مقایسه با ویژگی‌های مبنایی خاک به عنوان متغیرهای ورودی توابع انتقالی در مطالعه وضعیت نگهداشت آب در خاک بود. بدین منظور، تعداد 174 نمونه خاک جمع‌آوری و منحنی‌های بازتاب طیفی آنها در گستره 2500-350 نانومتر با استفاده از دستگاه اسپکترورادیومتر زمینی اندازه‌گیری شد. برخی ویژگی‌های فیزیکی خاک به همراه مقادیر رطوبت در پتانسیل های ماتریک 330-، 1000-، 3000-، 5000-، 10000- و 15000- سانتی‌متر به روش صفحات فشاری اندازه‌گیری شد. چهار سناریو شامل توابع انتقالی طیفی (STFs)، توابع انتقالی خاک (PTFs)، توابع انتقالی مرکب (SPTFs) و توابع انتقالیRosetta مورد بررسی و مقایسه قرار گرفت. بر پایه نتایج به‌دست آمده، همبستگی بالا و معنی‌داری در سطح 1 درصد بین ویژگی‌های مبنایی و هیدرولیکی خاک با مقادیر بازتاب طیفی به‌ویژه در گستره مادون قرمز میانی مشاهده شد. STFsدر مقایسه با دیگر توابع انتقالی، دقت بیشتری (011/0=RMSR سانتی‌متر مکعب بر سانتی‌متر مکعب، 60/0<R2) در برآورد رطوبت خاک در همه مکش‌ها به ویژه در بخش میانی و انتهای خشک منحنی رطوبتی داشت. از طرفی، SPTFs و PTFs دقت تقریباً یکسانی داشتند، با این تفاوت که در انتهای مرطوب منحنی رطوبتی (330- و 1000- سانتی‌متر)، PTFs برآورد‌های نسبتاً بهتری ارایه کردند. تخمین‌های Rosetta در مقایسه با سه تابع انتقالی دیگر، دقتی کمتر در همه مکش‌ها به ویژه در انتهای مرطوب منحنی رطوبتی داشتند. به طور کلی، نتایج این پژوهش نشان داد داده‌های طیفی خاک می‌توانند به عنوان روشی غیرمستقیم در مطالعه وضعیت نگهداشت آب در خاک مورد استفاده قرار گیرند. پرونده مقاله
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  4 - Trajectory Tracking Control of a Novel Planner Continuum Robot
  Seyed Shoja Amini ali keymasi khalaji
  10.30486/admt.2023.1959626.1353
  Researchers have a special fondness for continuum robots (CRs) due to their various applications. CRs have been modeled in different ways. One of these methods is called lumped model. Although the lumped modeling of CRs needs multiple degrees of freedom, researchers hav چکیده کامل

  Researchers have a special fondness for continuum robots (CRs) due to their various applications. CRs have been modeled in different ways. One of these methods is called lumped model. Although the lumped modeling of CRs needs multiple degrees of freedom, researchers have considered only a few degrees of freedom. But considering such structures led to some issues in the accuracy of the controller. Therefore, in this paper, the dynamic modeling of a CR which is based on the lumped model is developed in a general form. Additionally, a control strategy based on sliding mode back-stepping control is proposed after introducing the first and second Lyapunov functions for stability proof. Moreover, a new function in the control law is used to avoid chattering phenomena. The proposed controller can reduce the settling time, which is one of the most important factors in controlling such robots. To demonstrate the efficiency of the proposed method, three different case studies are conducted for a planar 8-DOF continuum manipulator and the simulations are compared with the feedback linearization method (FL). The simulations show the effectiveness of the proposed method for controlling the continuum robot. پرونده مقاله
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  5 - FEM Implementation of the Coupled Elastoplastic/Damage Model: Failure Prediction of Fiber Reinforced Polymers (FRPs) Composites
  I UD DIN P Hao M Aamir G Franz S Panier
  10.22034/jsm.2019.668617
  The coupled damage/plasticity model for meso-level which is ply-level in case of Uni-Directional (UD) Fiber Reinforced Polymers (FRPs) is implemented. The mathematical formulations, particularly the plasticity part, are discussed in a comprehensive manner. The plastic p چکیده کامل

  The coupled damage/plasticity model for meso-level which is ply-level in case of Uni-Directional (UD) Fiber Reinforced Polymers (FRPs) is implemented. The mathematical formulations, particularly the plasticity part, are discussed in a comprehensive manner. The plastic potential is defined in effective stress space and the damage evolution is based on the theory of irreversible thermodynamics. The model which is illustrated here has been implemented by different authors previously but, the complete pre-requisite algorithm ingredients used in the implicit scheme implementation are not available in the literature. This leads to the complexity in its implementation. Furthermore, this model is not available as a built-in material constitutive law in the commercial Finite Element Method (FEM) softwares. To facilitate the implementation and understanding, all the mathematical formulations are presented in great detail. In addition, the elastoplastic consistent operator needed for implementation in the implicit solution scheme is also derived. The model is formularized in incremental form to be used in the Return Mapping Algorithm (RMA). The quasi-static load carrying capability and non-linearity caused by the collaborative effect of damage and plasticity is predicted with User MATerial (UMAT) subroutine which solves the FEM problem with implicit techniques in ABAQUS. پرونده مقاله
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  6 - Multiscale Analysis of Transverse Cracking in Cross-Ply Laminated Beams Using the Layerwise Theory
  W Jin Na J.N Reddy
  A finite element model based on the layerwise theory is developed for the analysis of transverse cracking in cross-ply laminated beams. The numerical model is developed using the layerwise theory of Reddy, and the von Kármán type nonlinear strain field is چکیده کامل

  A finite element model based on the layerwise theory is developed for the analysis of transverse cracking in cross-ply laminated beams. The numerical model is developed using the layerwise theory of Reddy, and the von Kármán type nonlinear strain field is adopted to accommodate the moderately large rotations of the beam. The finite element beam model is verified by comparing the present numerical solutions with the elasticity solutions available in the literature; an excellent agreement is found. The layerwise beam model is then used to investigate the influence of transverse cracks on material properties and the response in cross-ply laminates using a multiscale approach. The multiscale analysis consists of numerical simulations at two different length scales. In the first scale, a mesoscale, a systematic procedure to quantify the stiffness reduction in the cracked ply is proposed exploiting the laminate theory. In the second scale, a macroscale, continuum damage mechanics approach is used to compute homogenized material properties for a unit cell, and the effective material properties of the cracked ply are extracted by the laminate theory. In the macroscale analysis, a beam structure under a bending load is simulated using the homogenized material properties in the layerwise finite element beam model. The stress redistribution in the beam according to the multiplication of transverse cracks is taken into account and a prediction of sequential matrix cracking is presented. پرونده مقاله
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  7 - A Mathematical Formulation to Estimate the Fundamental Period of High-Rise Buildings Including Flexural-Shear Behavior and Structural Interaction
  E Noroozinejad Farsangi H Melatdoust A Bin Adnan
  The objective of the current study is to develop a simple formula to estimate the fundamental vibration period of tall buildings for using in equivalent lateral force analysis specified in building codes. The method based on Sturm-Liouville differential equation is pres چکیده کامل

  The objective of the current study is to develop a simple formula to estimate the fundamental vibration period of tall buildings for using in equivalent lateral force analysis specified in building codes. The method based on Sturm-Liouville differential equation is presented here for estimating the fundamental period of natural vibration. The resulting equation, based on the continuum representation of tall buildings with various lateral resisting systems for natural vibration of the buildings, is proved to be the forth-order Sturm-Liouville differential equation, and a quick method for determining the fundamental period of natural vibration of the building is presented. Making use of the coupled wall theory for natural vibration, the method is extended to deal with vibration problem of other buildings braced by frame, walls or/and tube. The proposed formulation will allow a more consistent and accurate use of code formulae for calculating the earthquake-induced maximum base shear in a building. Use of the method is economical with respect to both computer time and equipment and can be used to verify the results of the finite element analyses where the time-consuming procedure of handling all the data can always be a source of errors. پرونده مقاله
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  8 - Quantum chemistry study on the regioselective behavior of 1,3-dipolar cycloaddition reaction of azides with various substituted cyclooctynes
  Marzieh Omrani Tayebeh Hosseinnejad
  The 1,3-Dipolar cycloaddition reactions are the classic reaction in modern synthetic organic chemistry.The Huisgen cycloaddition is the reaction of a dipolarophile with a 1,3-dipolar compound that leads to 5-membered heterocycles. With the goal of identifying alkyne-lik چکیده کامل

  The 1,3-Dipolar cycloaddition reactions are the classic reaction in modern synthetic organic chemistry.The Huisgen cycloaddition is the reaction of a dipolarophile with a 1,3-dipolar compound that leads to 5-membered heterocycles. With the goal of identifying alkyne-like reagents for use in azide-alkyne Huisgen cycloaddition reactions, we used density functional theory (DFT) and polarized continuum model (PCM) computations. In this respect, we investigated the structure and energy of transition states in the reaction path and assessed the trends in the calculated activation barriers for the1,3-dipolar cycloaddition of azides with various substituted cyclooctynes in the gas and solution phases to interpret theoretically the origin of regioselectivity in the synthesis of disubstituted 1,2,3-triazole derivatives. پرونده مقاله
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  9 - نقد و تحلیل پی رفت در منظومۀ غنائی مجنون و لیلی امیر خسرو دهلوی
  دکتر پوران یوسفی پور کرمانی
  از مهم‌ترین نظریه های ادبی، نظریه ی ساختارگرایی (structuralism) است که به بررسی و تحلیل ساختارهای عام در نظام‌های معناداری همچون زبان، ادبیات، داستان، اسطوره و ... می پردازد. تحلیل ساختاری داستان و روایت از زیباترین تحلیل‌های ادبی در نقد ادبی معاصر به شمار می آید. مجنون چکیده کامل

  از مهم‌ترین نظریه های ادبی، نظریه ی ساختارگرایی (structuralism) است که به بررسی و تحلیل ساختارهای عام در نظام‌های معناداری همچون زبان، ادبیات، داستان، اسطوره و ... می پردازد. تحلیل ساختاری داستان و روایت از زیباترین تحلیل‌های ادبی در نقد ادبی معاصر به شمار می آید. مجنون و لیلی جزو متون کهنی محسوب می‌شود که در ردۀ روایت‌های اسطوره‌ای به‌حساب می آید. بهترین تحلیل ساختاری مجنون و لیلی، با توجه به ساختار روایی آن‌که از داستان‌های حماسی و غنائی تشکیل‌شده است، روش ساختاری در تحلیل داستان های اسطوره ای است. در این مقاله که بخشی از یک پژوهش گسترده در پیوند با تحلیل ساختاری لیلی و مجنون است، تلاش شده چگونگی کاربرد پی‌رفت در این اثر ارزشمند بررسی شود. نخست لازم است هر داستان به یک پی رفت تقلیل یابد، به‌طوری‌که هر پی رفت چند کارکرد (حداکثر پنج) یا نقش ویژه را تشکیل دهد. کارکردهای درون هر پی رفت لازم است دربرگیرندۀ یک کنش روایی باشد و در پیشبرد توالی داستان (قصه) نقشی مهم ایفا کند. مهم‌ترین پی‌رفت‌های داستان لیلی و مجنون نیز عبارت است به مکتب رفتن لیلی و مجنون، عاشق شدن آن دو به هم، خواستگاری و مخالفت پدر لیلی، مرگ لیلی و مجنون، آرامش پس از مرگ لیلی و مجنون پرونده مقاله
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  10 - Solvent influence on the interaction of cis-PtCl2(NH3)2 complex and graphene: A theoretical study
  Reza Fazaeli E Ebrahimi Mokarram H Aghaei K Zare Mohammad Yousefi
  10.22034/jna.2018.575396.1104
  In this investigation the interaction of cis-PtCl2(NH3)2 complex and graphene were investigated with MPW1PW91 method in gas and solvent phases. The solvent effect were examined by the self-consistent reaction field theory (SCRF) based on Polarizable Continuum Model (PCM چکیده کامل

  In this investigation the interaction of cis-PtCl2(NH3)2 complex and graphene were investigated with MPW1PW91 method in gas and solvent phases. The solvent effect were examined by the self-consistent reaction field theory (SCRF) based on Polarizable Continuum Model (PCM). The selected solvents were chloroform, chlorobenzene, bromoethane, dimethyldisulfide, and dichloroethane. The solvent effect on the frontier orbital energy and HOMO-LUMO gap were studied. Negative value solvation energy of the between cis-Pt(NH3)2Cl2 …. graphene complex signifies the more stability of the complex in solution in compared to gas phase.The characterization of the interaction between two fragments was clarified with energy decomposition analysis (EDA). Pt-C(Graphene) and H(NH3)...C(Garaphen) interactions in the graphene … cis-PtCl2(NH3)2 complex were analyzed using quantum theory of atoms in molecules analysis (QTAIM). cis-Pt(NH3)2Cl2 and graphene fragments contribute in HOMO and LUMO of complex, respectively.In the basis of QTAIM analysis, the characteristics of the Pt…C(Graphene) and H(NH3)… C(Graphene) interactions was intermediate between closed-shell and shared interactions.EDA and structural parameters predict stronger interaction between cis-Pt(NH3)2Cl2 and graphene in gas phase. پرونده مقاله
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  11 - Solvent influence on the interaction of cis-PtCl2(NH3)2 complex and graphene: A theoretical study
  Elham Ebrahimi Mokarram Reza Fazaeli Hossein Aghaei Mohammad Yousefi Karim Zare
  10.22034/jna.2019.664400
  In this study the interaction of cis-PtCl2(NH3)2 complex and graphene were investigated with MPW1PW91method in gas and solvent phases. The solvent effect was examined by the self-consistent reaction fieldtheory (SCRF) based on Polarizable Continuum Model (PCM). The sele چکیده کامل

  In this study the interaction of cis-PtCl2(NH3)2 complex and graphene were investigated with MPW1PW91method in gas and solvent phases. The solvent effect was examined by the self-consistent reaction fieldtheory (SCRF) based on Polarizable Continuum Model (PCM). The selected solvents were chloroform,chlorobenzene, bromoethane, dimethyldisulfide, and dichloroethane. The solvent effect on thefrontier orbital energy and HOMO-LUMO gap were studied. The characterization of the interactionbetween two fragments was clarified with energy decomposition analysis (EDA). Pt-C(Graphene) andH(NH3)...C(Garaphen) interactions in the graphene … cis-PtCl2(NH3)2 complex were analyzed usingquantum theory of atoms in molecules analysis (QTAIM). پرونده مقاله
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  12 - Data Envelopment Analysis from simulation on the Lattice QCD using CCR model
  محمد حسین درویش متولی
  One of the most serious principles in production theory in economic is the principle of "efficiency". Simply put, efficiency can be defined as the demand that the desired goals (outputs) are achieved with the minimum use of the available resources (inputs). In order to, چکیده کامل

  One of the most serious principles in production theory in economic is the principle of "efficiency". Simply put, efficiency can be defined as the demand that the desired goals (outputs) are achieved with the minimum use of the available resources (inputs). In order to, distinguish the relative efficiency of organizational units with multiple inputs to produce multiple outputs, "Data Envelopment Analysis" (DEA) method was introduced by Charnes, Cooper and Rhodes. In fact, DEA is a linear mathematical programming which calculates the efficiency of an organization within a group relative to observed best practice within that group. Unlike common statistical analysis which are based on central tendencies, it is a methodology directed at the frontier. Recently, DEA has become one of the most favorite fields in operations research. The background was a motivation for us to in this paper, via running the CCR model in "DEA-Solver Software", present data envelopment analysis from simulation on the lattice QCD with temporal extent N_τ=4,6, respectively. Astonishingly, results are derived for both cases, indicating the fact that efficient data set belong to the areas of high temperature (deconfinement phase). It is very interesting to highlight that even an efficient data has not reported at low temperature (confinement phase). Note that the data obtained at the critical temperature is also efficient. As expected from practical lattice QCD, the DEA-CCR model presented in this paper also confirms the fact which the best data set arises from simulation in continuum limit a→0. Indeed, by taking the limit of vanishing lattice spacing, the efficiency of algorithms can be further. پرونده مقاله
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  13 - Comparison of Equivalent Continuum and Discontinuum Methods in Stability Analysis of a Natural Underground Karst
  Mahnaz Laghaei Alireza Baghbanan Masoud Torkan Siavash Norouzi Meysam Lak
  Stability analysis of the underground karsts around excavated and supported tunnels is one of the most important tasks in terms of safety evaluation of tunnels and underground excavations. In this paper, the stability and the stabilization method of a natural hole which چکیده کامل

  Stability analysis of the underground karsts around excavated and supported tunnels is one of the most important tasks in terms of safety evaluation of tunnels and underground excavations. In this paper, the stability and the stabilization method of a natural hole which existed before excavation above a transportation tunnel were investigated. The hole was modeled in form of continuous and discontinuous media. Several realizations with different crack patterns were generated in order to eliminate random effect. The stability was analyzed numerically. The results show that the equivalent continuum method induces overestimation upon strength parameters and consequently results in higher uncertainty compared to the discontinuum method which is a better representation of the problem. The generated models in discontinuous medium were highly unstable and showed prominent signs of collapse. As per the agreement between the discontinuous models with the real problem’s conditions, this instability and collapse of rock blocks may disturb the tunnel lining and yield to catastrophes. The results of using concrete foam as the filling and the whole support confirm the proper applicability of this approach alongside its practicability under the conditions specific to this project. پرونده مقاله
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  14 - Solvent Effects on Medicinal Structure and 15N NMR Shielding of Medazepam
  Arezoo Tahan Fatemeh Alimohammadi
  10.22034/jchr.2020.1892885.1102
  The Density Functional Theory (DFT) and Tomasi’s Polarized Continuum Model (PCM) were used to investigate the effects of solvent dielectric constant on the structural stability and 15N NMR tensors of Medazepam (MDZ) drug. The results revealed that the structural s چکیده کامل

  The Density Functional Theory (DFT) and Tomasi’s Polarized Continuum Model (PCM) were used to investigate the effects of solvent dielectric constant on the structural stability and 15N NMR tensors of Medazepam (MDZ) drug. The results revealed that the structural stability of MDZ in polar protic solvents was higher than that in the polar aprotic and non-polar solvents; and its value depended on the solvent dielectric constant and its structure. so that in most cases, relative stability increased by increasing the solvent dielectric constant and the most stable structures were observed in water media at DFT level and in methanol at MP2 level. In this regard, natural bond orbital (NBO) interpretation showed that the tetravalent N1 nucleus of diazepine ring in the MDZ structure had the highest value of negative charge and the resonance energy related to LP (1) N1 → σ* and π* delocalizations among heteroatoms of MDZ structure in the tested solvents. The findings reported that with an increase in the solvent dielectric constant, the resonance energy related to LP (1) N1 → σ* and π* delocalizations increased and the highest value of resonance energy was observed in water media. Furthermore, NMR results represented that the N1 nucleus had a higher value of chemical shielding than the trivalent N4 nucleus in all of the tested media. However, it may be concluded that by increasing the accumulation of negative charge and lone pair electrons participation of nitrogen nuclei in the resonance delocalizations, isotropic chemical shielding around them increase. پرونده مقاله
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  15 - Thermal Effect on the Torsional Buckling of Double Walled Carbon Nanotube Embedded in Pasternak Foundation
  علی قربانپور آرانی محمد شریف زارعی مهدی محمدی‌مهر
  In this study the effect of thermal stress on the torsional buckling of double walled carbon nanotubes is investigated. Moreover based on nonlocal continuum mechanic the buckling governing equations are obtained and equilibrium of Equations is generalized to double wall چکیده کامل

  In this study the effect of thermal stress on the torsional buckling of double walled carbon nanotubes is investigated. Moreover based on nonlocal continuum mechanic the buckling governing equations are obtained and equilibrium of Equations is generalized to double wall nanotubes. Also in this study the elastic medium, small scale effect and van der Walls force are considered. Also for simulation of the interaction between the polymer matrix and external tube Pasternak model is used. The numerical results indicate that critical buckling load occurs in the middle modes. Moreover for the Winkler related the Pasternak model the buckling occurs earlier. Results show that for rigid elastic medium in both case of Pasternak and Winkler models the buckling load is independent of their values Moreover from the result it can be seen that the buckling load has been increase as the thermal effect change. پرونده مقاله
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  16 - Bending Sector Graphene Sheet Based on the Elastic Winkler-Pstrnak with the Help of Nonlocal Elasticity Theory Using Developed Kantorovich Method
  شهریار دستجردی مهرداد جبارزاده
  In this study, the elastic bending of sector graphene sheet has been studied based on elasticity using Eringen Nonlocal Elasticity Theory. In order to do this, the balance equations governing the sector graphene sheet have been solved in terms of displacements with rega چکیده کامل

  In this study, the elastic bending of sector graphene sheet has been studied based on elasticity using Eringen Nonlocal Elasticity Theory. In order to do this, the balance equations governing the sector graphene sheet have been solved in terms of displacements with regard to nonlocal relationship of stress, shear theory of the first order, and obtained linear strains using developed Kantorovich method. In this method, the obtained partial differential equations are converted into two categories that can be solved using analytical and numerical methods. Developed Kantorovich method is a method with a high rate of convergence, in which the expected convergence is achieved with just three to four repetitions. With regard to the fact that no research has yet been conducted in this regard, the results, considering the nonlocal coefficient equal to zero, have been compared with other articles in order to check the validity. In the end, the effect of nonlocal coefficient variations on the results in terms of thickness, boundary conditions, hardness of elastic base and difference between nonlocal and local elasticity analysis has been studied. پرونده مقاله