Greenhouse Gas Observation Using Mobile FTIR

Beni Adi Trisna,Jeongsoon Lee 한국기상학회 2023 한국기상학회 학술대회 논문집 Vol.2023 No.4

Theoretical Studies of Hydrogen Bond Interactions in 4-Substituted Benzoic Acids Dimers

Beni, Alireza Salimi,Chermahini, Alireza Najafi,Sharghi, Hashem Korean Chemical Society 2011 대한화학회지 Vol.55 No.3

벤조산 유도체($NH_2$, OH, H, F, Cl, CN, NO, $NO_2$) 의 두 형태를 6-311++G(d,p) 바탕 집합을 이용하여 MP2, DFT 및 HF 수준으로 연구하였으며, cis이성 질체가 더 안정하였다. 벤조산의 수소 결합 형성은 안정화 에너지를 이용하여 추산하였으며, 이합체에 대한 수소결합 에너지 계산치는 고리에서 협동 상호작용이 일어남을 보여주었다. 페닐 고리로 전자를 밀어내는 그룹(ERG)은 더 안정한 수소 결합이 형성하였다. 이합체에서 O-H 결합의 적색이동은 -565.3에서 $-589.3\;cm^{-1}$ 범위였으며, 상호 작용의 특성은 NBO 분석을 이용하여 연구하였다. Two conformations of benzoic acid derivatives ($NH_2$, OH, H, F, Cl, CN, NO, $NO_2$) have been investigated at MP2, DFT and HF level using the 6-311++G(d,p) basis set. It was found that the cis isomers are more stable. Hydrogen bonding formation of benzoic acids has been estimated from stabilization energies. The calculated hydrogen-bonding energies of dimers showed a cooperative interaction in the cyclic ones. It was found that an electron-releasing group (ERG) into the phenyl rings resulted in the formation of more stable hydrogen bonding. Red shift of O-H bond was found from -565.3 to -589.3 for dimers. The natural bond orbital (NBO) analysis was applied to characterize nature of the interaction.

Modeling the effect of intermolecular force on the size-dependent pull-in behavior of beam-type NEMS using modified couple stress theory

Yaghoub Tadi Beni,Iman Karimipöur,Mohamadreza Abadyan 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.9

Experimental observations reveal that the physical response of nanostructures is size-dependent. Herein, modified couple stress theoryhas been used to study the effect of intermolecular van der Waals force on the size dependent pull-in of nanobridges and nanocantilevers. Three approaches including using differential transformation method, applying numerical method and developing a simple lumped parametermodel have been employed to solve the governing equation of the systems. The pull-in parameters i.e. critical tip deflection andinstability voltage of the nanostructures have been determined. Effect of the van der Waals attraction and the size dependency and theimportance of coupling between them on the pull-in performance have been discussed.

Finite element vibration analysis of nanoshell based on new cylindrical shell element

Soleimani, Iman,Beni, Yaghoub T.,Dehkordi, Mohsen B. Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.1

In this paper, using modified couple stress theory in place of classical continuum theory, and using shell model in place of beam model, vibrational behavior of nanotubes is investigated via the finite element method. Accordingly classical continuum theory is unable to correctly compute stiffness and account for size effects in micro/nanostructures, higher order continuum theories such as modified couple stress theory have taken on great appeal. In the present work the mass-stiffness matrix for cylindrical shell element is developed, and by means of size-dependent finite element formulation is extended to more precisely account for nanotube vibration. In addition to modified couple stress cylindrical shell element, the classical cylindrical shell element can also be defined by setting length scale parameter to zero in the equations. The boundary condition were assumed simply supported at both ends and it is shown that the natural frequency of nano-scale shell using the modified coupled stress theory is larger than that using the classical shell theory and the results of Ansys. The results have indicated using the modified couple stress cylindrical shell element, the rigidity of the nano-shell is greater than that in the classical continuum theory, which results in increase in natural frequencies. Besides, in addition to reducing the number of elements required, the use of this type of element also increases convergence speed and accuracy.

A Productive Maize-Soybean Relay Intercropping System for Food Production and Soil Fertility in Southwest China

Chun Song,Benying Su,Taiwen Yong,Wenyu Yang 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Caesalpinia sappan L. heartwood ethanolic extract exerts genotoxic inhibitory and cytotoxic effects

Edy Meiyanto,Beni Lestari,Raisatun Nisa Sugiyanto,Riris Istighfari Jenie,Rohmad Yudi Utomo,Ediati Sasmito,Retno Murwanti 경희대학교 융합한의과학연구소 2019 Oriental Pharmacy and Experimental Medicine Vol.19 No.1

Brazilin and brazilein, the major compounds of Caesalpinia sappan L. (CS) have been reported to possess antioxidant and cytotoxic activities and could potentially be used as an antigenotoxic as well as an anticancer. This study was conducted to investigate the cytotoxic and antigenotoxic effects of CS ethanolic extract (CEE). In vivo mammalian micronucleus test of CEE at the dose of 500 mg/kg BW and 1000 mg/kg BW decreased the number of MNPCE and increased the ratio of PCE to NCE meaning that CEE performed antigenotoxic effect in an in vivo model. In contrast, CEE and doxorubicin (DOXO) performed cytotoxic effect on CHO-K1 cells under MTT assay with IC50 values of 67 μg/mL and 6 μM, respectively. Interestingly, treatment of CEE in combination with DOXO and H2O2 as genotoxic inducer decreased intracellular ROS levels. In addition, in vitro genotoxicity study by using cytokinesis-block micronucleus (CBMN) assay, both of Giemsa staining and flow cytometric analysis showed that the treatment of CEE increased the number of micronuclei and correlated with apoptotic induction results. Moreover, the combination of CEE and DOXO induced cells accumulation in Sub-G1 and G2/M phase. In conclusion, CEE performed antigenotoxic effect in an in vivo model and cytotoxic effect on CHO-K1 cells.

Vibration analysis of boron nitride nanotubes by considering electric field and surface effect

Zeighampour, Hamid,Beni, YaghoubTadi Techno-Press 2021 Advances in nano research Vol.11 No.6

In this paper, the vibrations of boron nitride nanotubes (BNNTs) are investigated by considering the electric field. To consider the size effect at nanoscale dimensions, the surface elasticity theory is exploited. The equations of motion of the BNNTs are obtained by applying Hamilton's principle, and the clamped-guided boundary conditions are also considered. The governing equations and boundary conditions are discretized using the differential quadrature method (DQM), and the natural frequency is obtained by using the eigenvalue problem solution. The results are compared with the molecular dynamic simulation in order to validate the accurate values of the surface effects. In the molecular dynamics (MD) simulation, the potential between boron and nitride atoms is considered as the Tersoff type. The Timoshenko beam model is adopted to model BNNT. The vibrations of two types of zigzag and armchair BNNTs are considered. In the result section, the effects of chirality, surface elasticity modulus, surface residual tension, surface density, electric field, length, and thickness of BNNT on natural frequency are investigated. According to the results, it should be noted that, as an efficient non-classical continuum mechanic approach, the surface elasticity theory can be used in scrutinizing the dynamic behavior of BNNTs.

Electro-mechanical vibration of nanoshells using consistent size-dependent piezoelectric theory

Narges Ebrahimi,Yaghoub Tadi Beni 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.22 No.6

In this paper, the free vibrations of a short cylindrical nanotube made of piezoelectric material are studied based on the consistent couple stress theory and using the shear deformable cylindrical theory. This new model has only one length scale parameter and can consider the size effects of nanostructures in nanoscale. To model size effects in nanoscale, and considering the nanotube material which is piezoelectric, the consistent couple stress theory is used. First, using Hamilton's principle, the equations of motion and boundary condition of the piezoelectric cylindrical nanoshell are developed. Afterwards, using Navier approach and extended Kantorovich method (EKM), the governing equations of the system with simple-simple (S-S) and clamped-clamped (C-C) supports are solved. Afterwards, the effects of size parameter, geometric parameters (nanoshell length and thickness), and mechanical and electric properties (piezoelectric effect) on nanoshell vibrations are investigated. Results demonstrate that the natural frequency on nanoshell in nanoscale is extremely dependent on nanoshell size. Increase in size parameter, thickness and flexoelectric effect of the material leads to increase in frequency of vibrations. Moreover, increased nanoshell length and diameter leads to decreased vibration frequency.

The effect of small scale and intermolecular forces on the pull-in instability and free vibration of functionally graded nano-switches

Hosein Ataei,Yaghoub Tadi Beni,Milad Shojaeian 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.4

Pull-in instability and free vibration of cantilever and clamped-clamped beam-type nanoactuators, which are made of Functionally graded materials (FGMs), are investigated using the Modified strain gradient theory (MSGT) under the influence of electrostatic and intermolecular forces. It is assumed that the functionally graded nano-beam made of nickel and silicon nitride and mechanical properties of the nano-beam vary continuously and smoothly in the thickness direction by a simple power-law distribution. Differential quadrature method (DQM), Differential transformation method_Pade approximant (DTM_Pade) and Lumped parameter model (LPM) are used to solve the nonlinear governing equation of the nano-beam, and the obtained results from these methods are compared together. In the end, the effects of size, variation of the length scale parameter, and the volume fraction are discussed and examined. The results show that there are a good agreement between the MSGT and the experimental results, so it can be conclude that the size effect has a substantial impact on the pull-in instability and free vibration results of the beam-type micro/nanoactuator.

The effect of progesterone and 17-β estradiol on membrane-bound HLA-G in adipose derived stem cells

Akram Moslehi,Batool Hashemi-beni,Azam Moslehi,Maryam Ali Akbari,Minoo Adib 대한생리학회-대한약리학회 2016 The Korean Journal of Physiology & Pharmacology Vol.20 No.4

Membrane-bound HLA-G (mHLA-G) discovery on adipose derived stem cells (ADSCs) as a tolerogenic and immunosuppressive molecule was very important. Many documents have shown that HLA-G expression can be controlled via some hormones such as progesterone (P4) and estradiol (E2). Therefore, this study was designed to evaluate progesterone and estradiol effects on mHLA-G in ADSCs at restricted and combination concentrations. Three independent cell lines were cultured in complete free phenol red DMEM and subcultured to achieve suԀ cient cells. These cells were treated with P4, E2 and P4 plus E2 at physiologic and pregnancy concentrations for 3 days in cell culture conditions. The HLA-G positive ADSCs was measured via monoclonal anti HLA-G-FITC/ MEMG-09 by means of flow cytometry in nine groups. Data were analyzed by one way ANOVA and<em> </em>Tukey’s<em> post hoc</em> tests. There were no signì cant values of the mean percentage of HLA-G positive cells in E2-treated and the combination of P4 plus E2-treated ADSCs compared to control cells (p value>0.05) but P4 had a signì cant increase on mHLA-G in ADSCs (p value<0.05). High P4 concentration increased mHLA-G but E2 and the combination of P4 plus E₂ could not change mHLA-G on ADSCs.