Dynamic analysis of concrete beams reinforced with Tio2 nano particles under earthquake load

Morteza Sharifi,Reza Kolahchi,Mahmood Rabani Bidgoli 한국풍공학회 2018 Wind and Structures, An International Journal (WAS Vol.26 No.1

This research studies the dynamic analysis of a concrete column reinforced with titanium dioxide (TiO2) nanoparticles under earthquake load. The effect of nanoparticles accumulation in a region of concrete column is examined using Mori-Tanaka model. The structure is simulated mathematically based on the theory of sinusoidal shear deformation theory (SSDT). By calculating strain-displacement and stress-strain relations, the system energies include potential energy, kinetic energy, and external works are derived. Then, using the Hamilton\'s principle, the governing equations for the structure are extracted. Using these equations, the response of the concrete column under earthquake load is investigated using the numerical methods of differential quadrature (DQ) and Newark. The purpose of this study is to study the effects of percentage of nanoparticles, nanoparticles agglomeration, geometric parameters and boundary conditions on the dynamic response of the structure. The results indicate that by increasing the volume percent of TiO2 nanoparticles, the maximum dynamic deflection of the structure decreases.

Oil-oil correlation by FTIR spectroscopy of asphaltene samples

Morteza Asemani,Ahmad Reza Rabbani 한국지질과학협의회 2016 Geosciences Journal Vol.20 No.2

In this paper, a new technique with easy interpretation, low cost, and reliable results is presented for oil-oil correlation purpose. In this technique, the structural characterization of asphaltene, because of its structural similarity with kerogene and resistance to secondary processes (e.g., migration, biodegradation, thermal maturity, and so on), was considered as a correlation parameter and asphaltenes structure similarity in different oil samples is the basis of geochemical correlation. FTIR spectroscopy was applied to detect and compare asphaltene structures with each other. The four oil samples from different oil fields in the Iranian sector of the Persian Gulf were investigated by FTIR spectroscopy and introduced indexes that represent structural characteristic of asphaltenes enabled us to perform geochemical correlation. To validation of this technique, the other common geochemical techniques (e.g., stable carbon isotope and biomarkers) were applied to geochemical correlation. These techniques completely supported and complemented the results of the asphaltene FTIR spectroscopy technique. The results of these three techniques show genetic relationships among these 4 oil samples and indicated that these oil samples belong to two distinct oil families. The First oil family originated from carbonate rich source rock and the second oil family was sourced from calcareous shale source rock.

Classification and Regression Tree Analysis for Molecular Descriptor Selection and Binding Affinities Prediction of Imidazobenzodiazepines in Quantitative Structure-Activity Relationship Studies

Morteza Atabati,Kobra Zarei,Esmaeil Abdinasab 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.11

The use of the classification and regression tree (CART) methodology was studied in a quantitative structure-activity relationship (QSAR) context on a data set consisting of the binding affinities of 39 imidazobenzodiazepines for the α1 benzodiazepine receptor. The 3-D structures of these compounds were optimized using HyperChem software with semiempirical AM1 optimization method. After optimization a set of 1481 zero-to three-dimentional descriptors was calculated for each molecule in the data set. The response (dependent variable) in the tree model consisted of the binding affinities of drugs. Three descriptors (two topological and one 3D-Morse descriptors) were applied in the final tree structure to describe the binding affinities. The mean relative error percent for the data set is 3.20%, compared with a previous model with mean relative error percent of 6.63%. To evaluate the predictive power of CART cross validation method was also performed.

Comparison of model predictive controller and optimized min-max algorithm for turbofan engine fuel control

Morteza Montazeri-Gh,Ali Rasti 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.11

Min-max selector structure is traditionally used as the industrial control architecture of commercial turbofan engines. However, recent studies indicate that this structure with linear compensators suffers from lack of safety guarantee in fast demands. On the other hand, model predictive control (MPC) technique, which incorporates input/output constraints in its optimization process, has the potential to fulfill the control requirements of an aircraft engine. In this paper, a practical approach is performed for design and optimization of the turbofan engine controller through a comparative study where all control modes and requirements have been taken into account simultaneously. For this purpose, a thermodynamic nonlinear model is firstly developed for the turbofan engine. The linear regulators of minmax structure are then optimized via genetic algorithm (GA). The MPC technique is formulated based on the proper discrete-time linearized state-space models at desired operating points with real-time optimization, in which the MPC tuning horizons are obtained through GA optimization procedure. The both controllers are implemented on appropriate hardware taking the real-time aspects into account. Finally, a hardware in the loop (HIL) platform is developed for the turbofan engine electronic control unit (ECU) testing. The software and HIL simulation results confirm that MPC improves the response time of the system in comparison with min-max algorithm and guarantees the engine limit protection. This study demonstrates competitive advantages of MPC in terms of limit protection assurance and fast response, despite more computational burden.

Characterization of Al/Crystallized Al-Based Metallic Glass Composites Produced by Repeated Roll Bonding Process

Morteza Alizadeh,Saba Khoramkhorshid,Amir Hossein Taghvaei,Prashanth Konda Gokuldoss 대한금속·재료학회 2017 METALS AND MATERIALS International Vol.23 No.4

Devitrified Al84Gd6Ni7Co3 glassy particles have been used to reinforce Al-matrix composites through repeated rollbonding (RRB) process. Microstructural characterization of the produced composites after various rolling cycleswas performed by scanning electron microscopy. Mechanical properties of the fabricated composites were evaluatedby the tensile and microhardness tests. The results indicate that the RRB process is successful to producecomposites with the negligible amount of flaws and porosity, and it is followed by homogeneous distribution ofAl84Gd6Ni7Co3 particles in the Al matrix after nine rolling passes. Elongation of the composites improves significantlyupon RRB cycles and the tensile strength and microhardness of them increase more than two times comparedto unreinforced Al. According to fractography results, the enhanced mechanical properties are correlatedwith formation of excellent bonding at the interface of Al84Gd6Ni7Co3 particles and Al matrix. The theoretical valuesof composites hardness and yield strength calculated based on iso-strain model show a good agreement withrespect to the experimental results.

Combined 3D Printing Technologies and Material for Fabrication of Tactile Sensors

Morteza Vatani,Yanfeng Lu,Erik D. Engeberg,Jae-Won Choi 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

Recently, 3D printing technology has taken the spotlight internationally with the recognition of the importance of the manufacturing industry. Currently, there are many mature 3D printing processes and materials. However, an absence of fabrication capability of smart structures such as sensors and actuators remains. In this research, we present a hybrid manufacturing process including directprint/ cure (DPC) and projection-based stereolithography, along with printable materials for stretchable tactile sensors. The suggested DPC system consists of a robotically controlled micro-dispensing head, and a light curing module combined with projection stereolithography (PSL) retrofitted from a commercial projector. The materials developed in this research are based on a photocurable and stretchable liquid resin filled with multi-walled carbon nanotubes (MWNTs); this polymer/nanocomposite exhibits the piezoresistive property used in tactile sensing. We also used another hybrid process to develop a tactile sensor using a commercial machine to build the sensor body while a dispensing system was used to create the sensing elements. We have characterized the fabricated sensors with several experiments to detect the locations where forces are applied to the surfaces of the sensors. It is concluded that the suggested processes and materials are promising in developing accurate and reliable stretchable tactile sensors

Facile and low-cost synthesis of flexible nano-generators based on polymeric and porous aerogel materials

Morteza Beyranvand,Ahmad Gholizadeh 한국물리학회 2020 Current Applied Physics Vol.20 No.1

Triboelectric nano-generators (TE-NGs) can be utilized as a power supply for wireless systems, sensors, and operators. In this paper, new flexible TE-NGs that use sodium carboxymethyl cellulose (CMC), poly dimethyl siloxane (PDMS), polyvinylidene fluoride (PVDF), poly (4,4′-oxydiphenylene-pyromellitimide) (KAPTON) films and also sugar as a piezoelectric material were developed and are reported. Also, the outputs of NGs made by linear power under a periodic pressure of ~ 0.2 MPa at a frequency of 3 Hz showed that the highest output of NGs are related to PDMS–KATTON, PDMS, PVDF–KAPTON, PVDF, CMC NGs, respectively. It has been also observed that NGs connected in series to each other have a higher output than paralleled NGs so that their voltages increase at higher frequencies. Besides, a significant point is that the NGs are made in a low-cost, affordable, and environmentally-friendly route, which is a superior characteristic with respect to the rest of the NGs.

An investigation of the prevalence and causes of malnutrition in Iran: A review article and meta-analysis

Morteza Motedayen,Majid Dousti,Fatemeh Sayehmiri,Aziz A Pourmahmoudi 한국임상영양학회 2019 Clinical Nutrition Research Vol.8 No.2

Malnutrition is one of the most important health issues in developing countries, which might have adverse effects on the physical and intellectual health of children. The search process was started to find Persian and English articles published until September 2017 regarding the prevalence of malnutrition in children under the age of six in Iran using national and international databases including SID, Magiran, Irandoc, IranMedex, PubMed, Medline, Scopus, and ISI Web of Science. The data were analyzed using meta-analysis methods and the random effects model. The heterogeneity of studies was analyzed using the I2 index. The data were analyzed using R and STATA software (ver. 11.2). Twenty seven articles conducted from 2002 to 2016 were collected to be included in the meta-analysis process. The total sample size was 161,941 patients in an age range of 0-6 years. The final estimate of the prevalence of different forms of malnutrition through meta-analysis of data extracted from studies in Iran was as follows: severe underweight (1%; 95% confidence interval [CI], 1–1), moderate underweight (6%; 95% CI, 5–7), mild underweight (25%; 95% CI, 21–28), severe short stature (3%; 95% CI, 2–3), moderate short stature (8%; 95% CI, 6–9), mild short stature (21%; 95% CI, 17–24), severe slimness (1%; 95% CI, 1–1), moderate slimness (5%; 95% CI, 4–5) and mild slimness (20%; 95% CI, 17–24). Considering that the prevalence of malnutrition is relatively high in Iran, health authorities should plan to improve the nutritional status of children.

Identification and Damping of Resonances in Inverter-based Microgrids

Morteza Afrasiabi,Esmaeel Rokrok 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.4

The application of shunt capacitor banks and underground cables typically induces resonance in power distribution systems. In this study, the propagation of resonance in a microgrid (MG) with inverter-based distributed generators (IBDGs) is investigated. If resonances are not properly damped, then the output current of the inverters may experience distortion via resonance propagation due to the adverse effect of resonances on MG power quality. This study presents a conceptual method for identifying resonances and related issues in multi-inverter systems. For this purpose, existing resonances are identified using modal impedance analysis. However, some resonances may be undetectable when this method is used. Thus, the resonances are investigated using the proposed method based on the frequency response of a closed-loop MG equivalent circuit. After analyzing resonance propagation in the MG, an effective virtual impedance damping method is used in the IBDG control system to damp the resonances. Results demonstrate the effectiveness of the proposed method in compensating for existing resonances.

Incidence of exercise-associated hyponatremia during a high-altitude 161-km ultramarathon

( Morteza Khodaee ),( Anahita Saeedi ),( Christine Harris-Spinks ),( Tamara Hew-Butler ) 한국운동영양학회 2021 Physical Activity and Nutrition (Phys Act Nutr) Vol.25 No.3

[Purpose] Exercise-associated hyponatremia (EAH) is a well-known condition among endurance athletes at low altitudes. The incidence of EAH during ultramarathons at high altitudes warrants further investigation. This prospective observational study was conducted on the participants of the Leadville Trail 100 run, a 161- km race held at a high altitude (2,800 m-3,840 m). [Methods] Venous blood samples were collected before and immediately after the race. The participants completed an electronic survey after the race. Our main outcome measure was the post-race serum sodium ([Na⁺]) level. [Results] Of the 672 athletes who started the race, 351 (52%) successfully completed the event within the 30- hour cut-off. Post-race blood samples were collected from 84 runners (66 finishers). Both pre- and post-race blood samples were collected from 37 participants. Twenty percent of the post-race participants had EAH. Only one post-race participant had a [Na⁺] level of <130 mmol/L. All participants with EAH were asymptomatic. One participant had an abnormal pre-race [Na⁺] level (134 mmol/L). Female participants had a significantly higher rate of EAH than male participants (40% vs. 16%; p=0.039). Age, body mass index, weight changes, race completion status, nonsteroidal anti-inflammatory drug use, and urine specific gravity were not associated with the development of EAH. Lower postrace [Na⁺] levels were associated with higher serum creatine kinase values (R²=0.1, p<0.005). [Conclusion] High altitude (3,840 m peak) does not appear to enhance the incidence of EAH after an ultramarathon footrace. This suggests that ambient temperature (low temperatures reduce risk), sex (female predilection), endurance running, and overhydration are more prominent risk factors for EAH than high altitude.