Investigating of the effect of composite and welded connections on the cyclic behavior of steel bridges

Naseri, Ali,Roshan, Alireza Mirzagoltabar,Sabzevari, Asghar Techno-Press 2021 Coupled systems mechanics Vol.10 No.5

Connections play a significant role on the seismic performance of structures subjected to gravity and lateral loads. One of the most important strategies for plastic hinge transfer is the strengthening of connections. Composite and welded connections are commonly used in steel bridges. Each of these connections can affect the structural response to lateral loads such as cyclic loads. In this study, four steel bridge models with different types of connections, including composite and welded connections, are created in the finite element (FE) platform ABAQUS. After validation of a FE model using available experimental data, cyclic loading has been employed according to the load history proposed by Scientific Advisory Committee (SAC). The results indicate that using composite connections can increase shear capacity and improve ductility of the system. Also using composite connection can transfer stress concentrated from connection to other areas.

To What Extent Can Surface Morphology Influence the Photoelectrochemical Performance of Au:WO₃ Electrodes?

Naseri, N.,Qorbani, M.,Kim, H.,Choi, W.,Moshfegh, A. Z. American Chemical Society 2015 The Journal of Physical Chemistry Part C Vol.119 No.3

<P>Considering hydrogen as a future fuel, development of clean energy sources based on solar power is the main human challenge in recent years. Here, for the first time, Au:WO<SUB>3</SUB> photoanodes are synthesized with different Au concentrations and then applied for photoelectrochemical (PEC) water splitting. A comprehensive statistical study on the prepared photoanode surface is conducted to understand the correlation between surface morphology and PEC activity, using atomic force microscopy (AFM). The results clearly justified the maximum surface area observed for the film containing 1 mol % Au. Additionally, X-ray diffraction (XRD) analysis determined that Au nanocrystals have been formed in cubic structure with the size of 29–52 nm. X-ray photoelectron spectroscopy (XPS) revealed that the presence of Au in a combined metal/oxide state strongly affects on the Au:WO<SUB>3</SUB> photoanode performance. Photoresponse investigation of the synthesized films showed that the highest photocurrent was obtained for the sample containing 1 mol % gold with the maximum incident photon to current efficiency (IPCE) of about 20% at 360 nm wavelength. In addition, measuring the amount of hydrogen produced in the water splitting reaction supports the result that the sample containing 1 mol % Au exhibits the highest hydrogen production rate (∼3 μmol/h) as compared to other samples.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2015/jpccck.2015.119.issue-3/jp507988c/production/images/medium/jp-2014-07988c_0011.gif'></P>

Nanostructured Metal Organic Framework Modified Glassy Carbon Electrode as a High Efficient Non-Enzymatic Amperometric Sensor for Electrochemical Detection of H₂O₂

Naseri, Maryam,Fotouhi, Lida,Ehsani, Ali The Korean Electrochemical Society 2018 Journal of electrochemical science and technology Vol.9 No.1

Metal-organic frameworks have recently been considered very promising modifiers in electrochemical analysis due to their unique characteristics among which tunable pore sizes, crystalline ordered structures, large surface areas and chemical tenability are worth noting. In the present research, $Cu(btec)_{0.5}DMF$ was electrodeposited on the surface of glassy carbon electrode at room temperature under cathodic potential and was initially used as the active materials for the detection of $H_2O_2$. The cyclic voltammogram of $Cu(btec)_{0.5}DMF$ modified GC electrode shows distinct redox peaks potentials at +0.002 and +0.212 V in 0.1 M phosphate buffer solution (pH 6.5) corresponding to $Cu^{(II)}/Cu^{(I)}$ in $Cu(btec)_{0.5}DMF$. Acting as the electrode materials of a non-enzymatic $H_2O_2$ biosensor, the $Cu(btec)_{0.5}DMF$ brings about a promising electrocatalytic performance. The high electrocatalytic activity of the $Cu(btec)_{0.5}DMF$ modified GC electrode is demonstrated by the amperometric response towards $H_2O_2$ reduction with a wide linear range from $5{\mu}M$ to $8000{\mu}M$, a low detection limit of $0.865{\mu}M$, good stability and high selectivity at an applied potential of -0.2 V, which was higher than some $H_2O_2$ biosensors.

Probabilistic seismic assessment of RC box-girder bridges retrofitted with FRP and steel jacketing

Naseri, Ali,Roshan, Alireza Mirzagoltabar,Pahlavan, Hossein,Amiri, Gholamreza Ghodrati Techno-Press 2020 Coupled systems mechanics Vol.9 No.4

Due to susceptibility of bridges in the past earthquakes, vulnerability assessment and strengthening of bridges has gained a particular significance. The objective of the present study is to employ an analytical method for the development of fragility curves, as well as to investigate the effect of strengthening on the RC box-girder bridges. Since fragility curves are used for pre-and post-earthquake planning, this paper has attempted to adopt the most reliable modeling assumptions in order to increase the reliability. Furthermore, to acknowledge the interaction of soil, abutment and pile, the effect of different strengthening methods, such as using steel jacketing and FRP layers, the effect of increase in the bridge pier diameter, and the effect of vertical component of earthquake on the vulnerability of bridges in this study, a three-span RC box-girder bridge was modeled in 9 different cases. Nonlinear dynamic analyses were carried out on the studied bridges subjected to 100 ground motion records via OpenSEES platform. Therefore, the fragility curves were plotted and compared in the four damage states. The results revealed that once the interaction of soil and abutment and the vertical component of the earthquake are accounted for in the calculations, the median fragility is reduced, implying that the bridge becomes more vulnerable. It was also confirmed that steel jackets and FRP layers are suitable methods for pier strengthening which reduces the vulnerability of the bridge.

Effects of curvature radius on vulnerability of curved bridges subjected to near and far-field strong ground motions

Naseri, Ali,Roshan, Alireza MirzaGoltabar,Pahlavan, Hossein,Amiri, Gholamreza Ghodrati Techno-Press 2020 Structural monitoring and maintenance Vol.7 No.4

The specific characteristics of near-field earthquake records can lead to different dynamic responses of bridges compared to far-field records. However, the effect of near-field strong ground motion has often been neglected in the seismic performance assessment of the bridges. Furthermore, damage to horizontally curved multi-frame RC box-girder bridges in the past earthquakes has intensified the potential of seismic vulnerability of these structures due to their distinctive dynamic behavior. Based on the nonlinear time history analyses in OpenSEES, this article, assesses the effects of near-field versus far-field earthquakes on the seismic performance of horizontally curved multi-frame RC box-girder bridges by accounting the vertical component of the earthquake records. Analytical seismic fragility curves have been derived thru considering uncertainties in the earthquake records, material and geometric properties of bridges. The findings indicate that near-field effects reasonably increase the seismic vulnerability in this bridge sub-class. The results pave the way for future regional risk assessments regarding the importance of either including or excluding near-field effects on the seismic performance of horizontally curved bridges.

Frequency of K-RAS and N-RAS Gene Mutations in Colorectal Cancers in Southeastern Iran

Naseri, Mohsen,Sebzari, Ahmadreza,Haghighi, Fatemeh,Hajipoor, Fatemeh,Razavi, Fariba Emadian Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.9

Background: K-RAS and N-RAS gene mutations cause resistance to treatment in patients with colorectal cancer. Based on this, awareness of mutation of these genes is considered a clinically important step towards better diagnosis and appropriate treatment. Materials and Methods: Fifty paraffin-embedded blocks of colorectal cancer were obtained from Imam Reza Hospital of Birjand, Iran. Following DNA extraction, the samples were analyzed for common mutations of exons 2, 3 and 4 of KRAS and NRAS genes using real time PCR and pyrosequencing. Results: According to this study, the prevalence of mutations was respectively 28% (14 out of 50) and 2% (1 out of 50) in KRAS and NRAS genes. All the mutations were observed in patients >50 years old. Conclusions: Mutations were found in both KRAS and NRAS genes in colorectal cancers in Iranian patients. Determining the frequency of these mutations in each geographical region may be necessary to benefit from targeted cancer therapy.

Insights into the Mechanical Properties and Correlation Between Strain Path and Crystallographic Texture of the AA2024 Alloy During Severe Plastic Deformation

Majid Naseri,Mohsen Reihanian,Ahmad Ostovari Moghaddam,Davood Gholami,Mohammad Alvand,Ehsan Borhani,Evgeny Trofimov 대한금속·재료학회 2024 METALS AND MATERIALS International Vol.30 No.2

This study examined mechanical properties of AA2024 alloy and its correlation between strain path and crystallographictexture. Accumulative roll bonding (ARB) and cross accumulative roll bonding (CARB) were used to severely deformAA2024 alloys. Electron backscatter diffraction (EBSD) studies demonstrated that nano/ultrafine grains were formed by thestrain routes after eight cycles. It was also found that the lamellar boundary spacing and the mean boundary spacing were~ 360 ± 10 nm and 845 ± 10 nm after eight ARB cycles. In contrast to the ARB, the CARB specimen had equiaxed microstructurescharacterized by grains with a size of 150 and 100 nm. The CARB processed specimen exhibited a mean misorientationangle of 41.83° and a fraction of high angle grain boundaries of 78%, these values were 34.57° and 67% for ARB treatedspecimen, respectively. It was observed that the evolved texture is greatly affected by the strain paths. The ARB processedspecimen revealed strong Copper {112} <111>, Dillamor {4 4 11} <11 11 8>, S {123} <634>, and Brass {011} <211>components. In contrast, the CARB processed specimen showed major texture with prominent Copper {112} <111>, Brass{011} <211>, Rotated Cube {001} <110>, S {123} <634>, and Goss {011} <100> components. In the CARB specimen, theGoss/Brass texture ratio was intensified and the mechanical properties were superior (tensile strength: 535 MPa, microhardness:182 HV, elongation: 11.9%) compared with the ARB processed specimen (tensile strength: 455 MPa, microhardness:145 HV, elongation: 9.2%). Further, the change in strain path did not significantly affect the intensity of Goss and Cubecomponents, ruling out any further recrystallization tendency.

Energy analysis of the integration of HRV and direct evaporative cooling for energy efficiency in buildings: a case study in Iraq

Al-Naseri Husham,Fryer Robert,Samir Ali 대한설비공학회 2023 International Journal of Air-Conditioning and Refr Vol.31 No.1

Responding to climate change and adapting to global warming requires creative solutions. In Iraq, the most reliable and popular tool to have buildings cooled is airconditioning units (AC). While an evaporative cooler is not enough to achieve thermal comfort in a very hot climate, AC units consume a lot of energy which causes a significant load on the grid in Iraq resulting in increasing the emissions of CO 2 . This paper investigates the potential energy-saving associated with adopting a new arrangement of heat recovery ventilation (HRV) unit and evaporative cooler to achieve thermal comfort with far less energy. Two sets of efficiencies of both HRV and the evaporative cooler have been considered, and two different envelope performances are also investigated. To properly size the proposed system, an iterative process has been used until the smallest size of the proposed system enough to cool the building is determined. The proposed system has achieved considerable energy savings comprising a reduction of up to 66% in the cooling load energy consumption and a reduction of up to 44% in the overall energy consumption. Responding to climate change and adapting to global warming requires creative solutions. In Iraq, the most reliable and popular tool to have buildings cooled is airconditioning units (AC). While an evaporative cooler is not enough to achieve thermal comfort in a very hot climate, AC units consume a lot of energy which causes a significant load on the grid in Iraq resulting in increasing the emissions of CO2. This paper investigates the potential energy-saving associated with adopting a new arrangement of heat recovery ventilation (HRV) unit and evaporative cooler to achieve thermal comfort with far less energy. Two sets of efficiencies of both HRV and the evaporative cooler have been considered, and two different envelope performances are also investigated. To properly size the proposed system, an iterative process has been used until the smallest size of the proposed system enough to cool the building is determined. The proposed system has achieved considerable energy savings comprising a reduction of up to 66% in the cooling load energy consumption and a reduction of up to 44% in the overall energy consumption.

Effect of Motor Imagery on the F-Wave Parameters in Hemiparetic Stroke Survivors

Mahshid Naseri,Peyman Petramfar,Alireza Ashraf 대한재활의학회 2015 Annals of Rehabilitation Medicine Vol.39 No.3

Objective To assess the effect of motor imagery, as a rehabilitation method in stroke, on F-wave parameters that undergo changes during upper motor neuron involvement. Methods Twenty-one fully conscious hemiparetic stroke survivors with a completely plegic hand (power 0/5) and a minimum interval of 72 hours since stroke were recruited into this study. The mean F-wave latency, amplitude, and persistence in the median and ulnar nerves were measured in both the affected and non-affected sides at rest and in the paretic hand during a mental task. Comparison was made between data from the affected hand and the non-affected hand as well as between data from the affected hand at baseline and during motor imagery. Results Patients had significantly different F-wave persistence between the affected and non-affected sides (paired t-test, p<0.001). Motor imagery could improve F-wave persistence in both the investigated nerves (paired t-test, p=0.01 for ulnar nerve and p<0.001 for median nerve) and F-response amplitude in the median nerve (paired t-test, p=0.01) of the affected limb. Conclusion The amplitude and persistence of F-wave were improved during motor imagery, representing F-wave facilitation. This result suggests that motor imagery can restore motor neuron excitability, which is depressed after stroke.

Designing a Model for Selecting and Monitoring Supplier Cooperation Strategy

Poorya Naseri,Mortaza Abbasi,Karim Atashgar 대한산업공학회 2024 Industrial Engineeering & Management Systems Vol.23 No.2

This article examines selection of the cooperation model with the supplier and monitoring the cooperation strategy over time by continuously monitoring the performance of the supplier over time. For this purpose, a multivariate fuzzy profile monitoring model by considering risk conditions in two stages for monitoring the suppliers unforeseen costs. In the first step, criteria are extracted to evaluate the delivery process, quality, as well as the risk function according to library resources and the opinion of experts of the industry. in the first phase of monitoring using the T^2 method, the parameters of the model based on successive differences are calculated and monitored separately for the multivariate multiple profile of the delivery process and quality, taking risk into account, and in the second phase of the method The likelihood ratio is used to monitor the profiles in a fuzzy manner over time, so that if there is an alarm, the control chart will show it in the shortest possible time. In the last stage, using the results of the fuzzy profiles and using tool of the fuzzy inference system, it is used to monitor the unforeseen costs and make a decision about the supplier and monitor the cooperation strategy.